WO2004010489A1 - 縦型接合型電界効果トランジスタ、及び縦型接合型電界効果トランジスタの製造方法 - Google Patents
縦型接合型電界効果トランジスタ、及び縦型接合型電界効果トランジスタの製造方法 Download PDFInfo
- Publication number
- WO2004010489A1 WO2004010489A1 PCT/JP2003/009412 JP0309412W WO2004010489A1 WO 2004010489 A1 WO2004010489 A1 WO 2004010489A1 JP 0309412 W JP0309412 W JP 0309412W WO 2004010489 A1 WO2004010489 A1 WO 2004010489A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- semiconductor
- semiconductor portion
- conductivity type
- drift
- region
- Prior art date
Links
- 230000005669 field effect Effects 0.000 title claims description 125
- 238000000034 method Methods 0.000 title claims description 62
- 239000004065 semiconductor Substances 0.000 claims abstract description 2007
- 239000010410 layer Substances 0.000 claims description 311
- 239000002019 doping agent Substances 0.000 claims description 157
- 238000004519 manufacturing process Methods 0.000 claims description 59
- 239000012535 impurity Substances 0.000 claims description 43
- 239000000758 substrate Substances 0.000 claims description 37
- 239000000463 material Substances 0.000 claims description 15
- 238000005530 etching Methods 0.000 claims description 13
- 230000005684 electric field Effects 0.000 claims description 12
- 230000000694 effects Effects 0.000 claims description 6
- 239000011229 interlayer Substances 0.000 claims description 4
- 230000002093 peripheral effect Effects 0.000 claims 2
- 230000000149 penetrating effect Effects 0.000 claims 1
- 102000004129 N-Type Calcium Channels Human genes 0.000 abstract description 70
- 108090000699 N-Type Calcium Channels Proteins 0.000 abstract description 70
- 108091006146 Channels Proteins 0.000 description 214
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 132
- 229910010271 silicon carbide Inorganic materials 0.000 description 131
- 229910052751 metal Inorganic materials 0.000 description 30
- 239000002184 metal Substances 0.000 description 30
- 230000015556 catabolic process Effects 0.000 description 26
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 15
- 230000004048 modification Effects 0.000 description 15
- 238000012986 modification Methods 0.000 description 15
- 229920002120 photoresistant polymer Polymers 0.000 description 15
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 14
- 230000003647 oxidation Effects 0.000 description 14
- 238000007254 oxidation reaction Methods 0.000 description 14
- 229910052710 silicon Inorganic materials 0.000 description 14
- 239000010703 silicon Substances 0.000 description 14
- 238000010586 diagram Methods 0.000 description 11
- 238000000407 epitaxy Methods 0.000 description 10
- 238000009792 diffusion process Methods 0.000 description 9
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 8
- 239000000969 carrier Substances 0.000 description 8
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 7
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 7
- 229910052814 silicon oxide Inorganic materials 0.000 description 7
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 6
- 229910052782 aluminium Inorganic materials 0.000 description 6
- 239000010949 copper Substances 0.000 description 6
- 238000005468 ion implantation Methods 0.000 description 6
- 230000001590 oxidative effect Effects 0.000 description 6
- 229910021420 polycrystalline silicon Inorganic materials 0.000 description 6
- 229920005591 polysilicon Polymers 0.000 description 6
- 230000015572 biosynthetic process Effects 0.000 description 5
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 5
- 229910052721 tungsten Inorganic materials 0.000 description 5
- 239000010937 tungsten Substances 0.000 description 5
- 239000004020 conductor Substances 0.000 description 4
- 229910052757 nitrogen Inorganic materials 0.000 description 4
- 230000000737 periodic effect Effects 0.000 description 4
- 239000010936 titanium Substances 0.000 description 4
- JBRZTFJDHDCESZ-UHFFFAOYSA-N AsGa Chemical compound [As]#[Ga] JBRZTFJDHDCESZ-UHFFFAOYSA-N 0.000 description 3
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 3
- 229910001218 Gallium arsenide Inorganic materials 0.000 description 3
- JMASRVWKEDWRBT-UHFFFAOYSA-N Gallium nitride Chemical compound [Ga]#N JMASRVWKEDWRBT-UHFFFAOYSA-N 0.000 description 3
- 229910052786 argon Inorganic materials 0.000 description 3
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- 229910052796 boron Inorganic materials 0.000 description 3
- 238000005229 chemical vapour deposition Methods 0.000 description 3
- 229910052802 copper Inorganic materials 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 239000011261 inert gas Substances 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- 239000001301 oxygen Substances 0.000 description 3
- 229910000838 Al alloy Inorganic materials 0.000 description 2
- 229910002601 GaN Inorganic materials 0.000 description 2
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 2
- 229910052785 arsenic Inorganic materials 0.000 description 2
- RQNWIZPPADIBDY-UHFFFAOYSA-N arsenic atom Chemical compound [As] RQNWIZPPADIBDY-UHFFFAOYSA-N 0.000 description 2
- 239000007772 electrode material Substances 0.000 description 2
- 125000005842 heteroatom Chemical group 0.000 description 2
- 238000009413 insulation Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 229910052698 phosphorus Inorganic materials 0.000 description 2
- 239000011574 phosphorus Substances 0.000 description 2
- 230000003068 static effect Effects 0.000 description 2
- 229910052719 titanium Inorganic materials 0.000 description 2
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 229910021478 group 5 element Inorganic materials 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 229910000077 silane Inorganic materials 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
- H01L29/66007—Multistep manufacturing processes
- H01L29/66053—Multistep manufacturing processes of devices having a semiconductor body comprising crystalline silicon carbide
- H01L29/66068—Multistep manufacturing processes of devices having a semiconductor body comprising crystalline silicon carbide the devices being controllable only by the electric current supplied or the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched, e.g. three-terminal devices
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/02—Semiconductor bodies ; Multistep manufacturing processes therefor
- H01L29/06—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions
- H01L29/0603—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions characterised by particular constructional design considerations, e.g. for preventing surface leakage, for controlling electric field concentration or for internal isolations regions
- H01L29/0607—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions characterised by particular constructional design considerations, e.g. for preventing surface leakage, for controlling electric field concentration or for internal isolations regions for preventing surface leakage or controlling electric field concentration
- H01L29/0611—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions characterised by particular constructional design considerations, e.g. for preventing surface leakage, for controlling electric field concentration or for internal isolations regions for preventing surface leakage or controlling electric field concentration for increasing or controlling the breakdown voltage of reverse biased devices
- H01L29/0615—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions characterised by particular constructional design considerations, e.g. for preventing surface leakage, for controlling electric field concentration or for internal isolations regions for preventing surface leakage or controlling electric field concentration for increasing or controlling the breakdown voltage of reverse biased devices by the doping profile or the shape or the arrangement of the PN junction, or with supplementary regions, e.g. junction termination extension [JTE]
- H01L29/063—Reduced surface field [RESURF] pn-junction structures
- H01L29/0634—Multiple reduced surface field (multi-RESURF) structures, e.g. double RESURF, charge compensation, cool, superjunction (SJ), 3D-RESURF, composite buffer (CB) structures
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/02—Semiconductor bodies ; Multistep manufacturing processes therefor
- H01L29/06—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions
- H01L29/10—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions with semiconductor regions connected to an electrode not carrying current to be rectified, amplified or switched and such electrode being part of a semiconductor device which comprises three or more electrodes
- H01L29/1025—Channel region of field-effect devices
- H01L29/1029—Channel region of field-effect devices of field-effect transistors
- H01L29/1058—Channel region of field-effect devices of field-effect transistors with PN junction gate
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/02—Semiconductor bodies ; Multistep manufacturing processes therefor
- H01L29/06—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions
- H01L29/10—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions with semiconductor regions connected to an electrode not carrying current to be rectified, amplified or switched and such electrode being part of a semiconductor device which comprises three or more electrodes
- H01L29/1066—Gate region of field-effect devices with PN junction gate
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
- H01L29/66007—Multistep manufacturing processes
- H01L29/66075—Multistep manufacturing processes of devices having semiconductor bodies comprising group 14 or group 13/15 materials
- H01L29/66227—Multistep manufacturing processes of devices having semiconductor bodies comprising group 14 or group 13/15 materials the devices being controllable only by the electric current supplied or the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched, e.g. three-terminal devices
- H01L29/66409—Unipolar field-effect transistors
- H01L29/66446—Unipolar field-effect transistors with an active layer made of a group 13/15 material, e.g. group 13/15 velocity modulation transistor [VMT], group 13/15 negative resistance FET [NERFET]
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
- H01L29/66007—Multistep manufacturing processes
- H01L29/66075—Multistep manufacturing processes of devices having semiconductor bodies comprising group 14 or group 13/15 materials
- H01L29/66227—Multistep manufacturing processes of devices having semiconductor bodies comprising group 14 or group 13/15 materials the devices being controllable only by the electric current supplied or the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched, e.g. three-terminal devices
- H01L29/66409—Unipolar field-effect transistors
- H01L29/66893—Unipolar field-effect transistors with a PN junction gate, i.e. JFET
- H01L29/66901—Unipolar field-effect transistors with a PN junction gate, i.e. JFET with a PN homojunction gate
- H01L29/66909—Vertical transistors, e.g. tecnetrons
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
- H01L29/68—Types of semiconductor device ; Multistep manufacturing processes therefor controllable by only the electric current supplied, or only the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched
- H01L29/76—Unipolar devices, e.g. field effect transistors
- H01L29/772—Field effect transistors
- H01L29/80—Field effect transistors with field effect produced by a PN or other rectifying junction gate, i.e. potential-jump barrier
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
- H01L29/68—Types of semiconductor device ; Multistep manufacturing processes therefor controllable by only the electric current supplied, or only the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched
- H01L29/76—Unipolar devices, e.g. field effect transistors
- H01L29/772—Field effect transistors
- H01L29/80—Field effect transistors with field effect produced by a PN or other rectifying junction gate, i.e. potential-jump barrier
- H01L29/808—Field effect transistors with field effect produced by a PN or other rectifying junction gate, i.e. potential-jump barrier with a PN junction gate, e.g. PN homojunction gate
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
- H01L29/68—Types of semiconductor device ; Multistep manufacturing processes therefor controllable by only the electric current supplied, or only the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched
- H01L29/76—Unipolar devices, e.g. field effect transistors
- H01L29/772—Field effect transistors
- H01L29/80—Field effect transistors with field effect produced by a PN or other rectifying junction gate, i.e. potential-jump barrier
- H01L29/808—Field effect transistors with field effect produced by a PN or other rectifying junction gate, i.e. potential-jump barrier with a PN junction gate, e.g. PN homojunction gate
- H01L29/8083—Vertical transistors
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/02—Semiconductor bodies ; Multistep manufacturing processes therefor
- H01L29/12—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by the materials of which they are formed
- H01L29/16—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by the materials of which they are formed including, apart from doping materials or other impurities, only elements of Group IV of the Periodic System
- H01L29/1608—Silicon carbide
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/02—Semiconductor bodies ; Multistep manufacturing processes therefor
- H01L29/12—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by the materials of which they are formed
- H01L29/20—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by the materials of which they are formed including, apart from doping materials or other impurities, only AIIIBV compounds
- H01L29/2003—Nitride compounds
Definitions
- the present invention relates to a vertical junction field effect and a vertical junction field effect manufacturing method.
- JFET Junction Field Effect Transistor
- the JFET has a channel region located between the source electrode and the drain electrode and in contact with the Good electrode, and has a thickness of a depletion layer formed by a pn junction formed by the Good semiconductor layer and the channel semiconductor layer. This is a device that controls the drain current flowing through the channel region by varying the voltage applied to the gate electrode.
- MOS FET metal oxide film / semiconductor field effect transistor
- IGBTs insulated gate bipolar transistors
- thyristors are the mainstream.
- an electrostatic induction transistor which is a type of JFET, has been developed and commercialized as a power semiconductor.
- the SIT has a device structure similar to that of the JFET, but the static characteristics of the JFET are pentode characteristics having saturation, whereas the static characteristics of the SIT are triode characteristics characterized by non-saturation. Disclosure of the invention
- Gap semiconductor materials are attracting attention as semiconductor materials capable of realizing superior power semiconductor devices with higher breakdown voltage, lower loss, higher output and higher frequency operation than silicon.
- SiC silicon carbide
- GaN gallium nitride
- Gap semiconductor materials are attracting attention as semiconductor materials capable of realizing superior power semiconductor devices with higher breakdown voltage, lower loss, higher output and higher frequency operation than silicon.
- high breakdown voltage and low loss a loss of more than two orders of magnitude can be expected for lkV breakdown voltage compared to silicon.
- a promising low-loss device has not been developed for a MOS structure device because the surface mobility immediately below the oxide film is small.
- an advantage of the MOS structure is that it is a voltage-driven normally-off type. Therefore, the inventors have focused on JFET, whose characteristics are characterized by the mobility inside the crystal, which has not been widely developed in silicon, and have come to study a high-voltage low-loss device. In addition, J FET for normally-off devices is possible. In addition, it was determined that a structure in which a current flows in a direction from the front surface to the back surface of the substrate was preferable as a power device, and a vertical JFET was examined.
- an object of the present invention is to provide a vertical junction field effect transistor having low loss while maintaining high drain withstand voltage, and a method of manufacturing the vertical junction field effect transistor.
- the vertical junction field effect transistor according to the present invention includes a drain semiconductor section, a drift semiconductor section, a buried semiconductor section, a channel semiconductor section, a source semiconductor section, and a gate.
- the drift semiconductor unit is provided on the main surface of the drain semiconductor unit, and has first, second, third, and fourth regions extending in a predetermined axial direction intersecting the main surface.
- the embedded semiconductor section has a conductivity type and a reverse conductivity type of the drift semiconductor section, and is provided on the first, second, and third regions of the drift semiconductor section.
- the channel semiconductor section is provided along the embedded semiconductor section, has a conductivity type opposite to that of the embedded semiconductor section, and is electrically connected to the fourth region of the drift semiconductor section.
- the source semiconductor unit is provided on the first region of the drift semiconductor unit and the channel semiconductor unit.
- the gate semiconductor portion has a conductivity type opposite to that of the drain semiconductor portion, and is provided on the third and fourth regions and the channel semiconductor portion.
- the good semiconductor portion has a plurality of convex portions extending in a direction from the third region to the fourth region, a channel semiconductor portion is provided between the convex portions, and the convex portion is an embedded semiconductor. Connected to the unit.
- the buried semiconductor portion and the channel semiconductor portion can be arranged on the drift semiconductor portion.
- the sum of the loss of the channel semiconductor portion and the loss of the drift semiconductor portion becomes the basic loss of the device. For this reason, if the breakdown voltage of the device is made high by only the channel semiconductor portion, the impurity concentration of the channel becomes low, the channel length becomes long, and the loss of the device becomes large.
- the channel semiconductor portion can have a high impurity concentration and a short channel length, so that the loss of the channel semiconductor portion can be reduced.
- the drift semiconductor section can obtain a desired drain withstand voltage depending on the impurity concentration and the thickness thereof, and the loss can be minimized.
- the vertical junction field-effect transistor includes a drain semiconductor part, a drift semiconductor part, a buried semiconductor part, a channel semiconductor part, a source semiconductor part, and a plurality of gate semiconductor parts.
- the drift semiconductor portion is provided on a main surface of the drain semiconductor portion, and has first, second, third, and fourth regions extending in a predetermined axial direction intersecting the main surface.
- the embedded semiconductor section has a conductivity type opposite to that of the drift semiconductor section, and is provided on the first, second, and third regions of the drift semiconductor section.
- the channel semiconductor section is provided along the embedded semiconductor section, and has a conductivity type opposite to that of the embedded semiconductor section. It has a conductivity type and is electrically connected to the fourth region of the drift semiconductor portion.
- the source semiconductor unit is provided on the first region of the drift semiconductor unit and the channel semiconductor unit.
- the plurality of gate semiconductor units have a conductivity type opposite to that of the drain semiconductor unit, and are provided on the third and fourth regions and the channel semiconductor unit.
- Each of the plurality of gate semiconductor portions extends in a direction from the third region toward the fourth region, and a channel semiconductor portion is provided between the plurality of gate semiconductor portions. It is connected to the embedded semiconductor section.
- the channel semiconductor portion is provided between the plurality of gate semiconductor portions, the channel semiconductor portion is controlled from both sides. Therefore, the thickness of the channel can be increased and the loss can be reduced.
- the vertical junction field-effect transistor includes a drain semiconductor section, a drift semiconductor section, a buried semiconductor section, a channel semiconductor section, and a gate semiconductor section.
- the drift semiconductor portion is provided on the main surface of the drain semiconductor portion, and has first, second, third, and fourth regions extending in a predetermined axial direction intersecting the main surface.
- the embedded semiconductor portion is provided on the main surface of the drift semiconductor portion, and is provided on first, second, and third regions extending in a predetermined axial direction intersecting with the main surface.
- the channel semiconductor portion is provided along the buried semiconductor portion, has a conductivity type opposite to that of the buried semiconductor portion, and is electrically connected to the fourth region of the drift semiconductor portion.
- the gate semiconductor unit has a conductivity type opposite to that of the drift semiconductor unit, and is provided on the third and fourth regions and the channel semiconductor unit.
- the gate semiconductor portion has a plurality of protrusions extending in a direction from the third region to the fourth region, a channel semiconductor portion is provided between the protrusions, and the drift semiconductor portion has It is connected to the embedded semiconductor section.
- the drift semiconductor portion has a fifth region extending in the axial direction intersecting the main surface of the drain semiconductor portion, has a conductivity type opposite to that of the drain semiconductor portion, and is provided on the fifth region.
- the semiconductor device further includes the obtained second semiconductor unit.
- the second semiconductor portion extends in a predetermined axial direction from the buried semiconductor portion along the source semiconductor portion. According to such a transistor, since the channel semiconductor portion is provided between the buried semiconductor portion and the gate semiconductor portion, the channel semiconductor portion is controlled from both sides. Therefore, the thickness of the channel can be increased and the loss can be reduced.
- the vertical junction field-effect transistor further includes a first semiconductor unit.
- the first semiconductor unit is provided on the first and second regions of the drift semiconductor unit and the channel semiconductor unit, and has the same conductivity type as the source semiconductor unit.
- the dopant concentration of the first semiconductor portion is preferably lower than the dopant concentration of the channel semiconductor portion.
- the first semiconductor portion is provided between the channel semiconductor portion and the source semiconductor portion.
- the thickness tolerance of the channel semiconductor portion accompanying the etching can be absorbed. Therefore, individual differences in the electrical characteristics of the vertical junction field effect transistor can be reduced.
- the vertical junction field-effect transistor includes a drain semiconductor section, a drift semiconductor section, an embedded semiconductor section, a plurality of gate semiconductor sections, a channel semiconductor section, a connection semiconductor section, and a
- the semiconductor device includes one grouped semiconductor part, a second grouped semiconductor part, and a source semiconductor part.
- the drift semiconductor portion is provided on a main surface of the drain semiconductor portion, and has first to fifth regions extending in a predetermined axial direction intersecting with a reference surface extending along the main surface.
- the buried semiconductor section has a conductivity type opposite to that of the drift semiconductor section, and is provided along the reference plane on the first to fourth regions of the drift semiconductor section.
- the plurality of gate semiconductor units are provided along the reference plane on the second to fourth regions of the drift semiconductor unit, and have the same conductivity type as the buried semiconductor unit.
- the channel semiconductor section is provided between the embedded semiconductor section and the plurality of gate semiconductor sections and between the plurality of gate semiconductor sections, and has a conductivity type opposite to that of the embedded semiconductor section.
- the connection semiconductor portion has the same conductivity type as the buried semiconductor portion and the channel semiconductor portion, extends in a predetermined axial direction, and connects the buried semiconductor portion and the plurality of gate semiconductor portions.
- the first collective semiconductor unit connects the channel semiconductor unit on the first region of the drift semiconductor unit.
- the second collective semiconductor section connects the channel semiconductor section on the fifth region of the drift semiconductor section.
- the source semiconductor unit is provided on the first region of the drift semiconductor unit, and is connected to the first collective semiconductor unit.
- a channel region is provided between the buried semiconductor portion and a plurality of gate semiconductor portions. Therefore, the number of channel regions that can be controlled by the gate semiconductor portion can be increased. Further, the buried semiconductor section and the channel semiconductor section can be arranged on the drift semiconductor section. Therefore, a desired drain withstand voltage can be obtained depending on the thickness of the drift semiconductor portion.
- the vertical junction field effect transistor includes a drain semiconductor part, a drift semiconductor part, a buried semiconductor part, a plurality of gate semiconductor parts, a channel semiconductor part, and a connection semiconductor part. , A first integrated semiconductor section, a second integrated semiconductor section, a source semiconductor section, and a third connecting semiconductor section.
- the drift semiconductor portion is provided on the main surface of the drain semiconductor portion, and has first to fifth regions extending in a predetermined axial direction intersecting with a reference surface extending along the main surface.
- the buried semiconductor section has a conductivity type opposite to that of the drift semiconductor section, and is provided along the reference plane on the first to fourth regions of the drift semiconductor section.
- the plurality of gate semiconductor units are provided along the reference plane on the second to fourth regions of the drift semiconductor unit, and have the same conductivity type as the buried semiconductor unit.
- the channel semiconductor section is provided between the buried semiconductor section and the plurality of gate semiconductor sections and between the plurality of gate semiconductor sections, and has a conductivity type opposite to that of the buried semiconductor section.
- the connection semiconductor section has the same conductivity type as the channel semiconductor section, and connects a plurality of gate semiconductor sections.
- the first collective semiconductor unit connects the channel semiconductor unit on the first region of the drift semiconductor unit.
- the second collective semiconductor unit connects the channel semiconductor unit on the fifth region of the drift semiconductor unit.
- the source semiconductor section is provided on the first region of the drift semiconductor section, and is connected to the first collective semiconductor section.
- the drift semiconductor portion has a sixth region provided on the main surface and extending in a direction intersecting the main surface.
- the third connection semiconductor part is a conductive type of the drain semiconductor part. And has a reverse conductivity type and is provided on the sixth region.
- the third connection semiconductor section is provided along the first collective semiconductor section.
- the plurality of gate semiconductor units are electrically connected to the embedded semiconductor unit via the third connection semiconductor unit. This allows both the buried semiconductor portion and the plurality of gate semiconductor portions to be used as gates. Therefore, the thickness of the controllable channel is increased.
- the thickness of the gate semiconductor portion and the thickness of the channel semiconductor portion are smaller than the distance between the buried semiconductor portion on the first region of the drift semiconductor portion and the source semiconductor portion. Is preferred.
- the thicknesses of the plurality of gate semiconductor portions and the channel semiconductor portion on the second to fourth regions of the drift semiconductor portion are different from those of the drift semiconductor portion. It is preferable that the distance between the buried semiconductor portion and the source semiconductor portion on the first region is smaller than that.
- the embedded semiconductor portion can be separated from the source semiconductor portion. Thereby, the breakdown voltage between the gate and the source is improved. Also, since the distance between the channel semiconductor portion and the source semiconductor portion is set in the vertical direction, even if this distance is increased, the chip size of the transistor does not increase.
- the interval between the protrusions of the gate semiconductor portion is determined such that the vertical junction field effect transistor exhibits normally-off characteristics.
- the distance between the protrusions of the gate semiconductor portion and the distance between the protrusions of the gate semiconductor portion and the buried semiconductor portion are determined by the vertical junction field effect transistor.
- the effect transistor is determined so as to exhibit normally-off characteristics.
- the distance between each gate semiconductor portion and the distance between the gate semiconductor portion and the buried semiconductor portion are determined by the vertical junction field-effect transistor.
- the combined field effect transistor is determined so as to exhibit normally-off characteristics.
- each gate semiconductor portion is designed such that a depletion layer generated by a diffusion potential between the buried semiconductor portion and the channel semiconductor portion having the opposite conductivity type spreads over the entire channel semiconductor portion. It is easy to reduce the impurity concentration and the thickness of the channel semiconductor portion. Therefore, even if no gate voltage is applied, the channel semiconductor portion can be depleted, and a normally-off transistor can be realized.
- the channel semiconductor portion has a structure in which low-concentration layers and high-concentration layers are alternately stacked.
- the drift semiconductor portion of the vertical junction field effect transistor extends along a reference plane intersecting the main surface of the drain semiconductor portion and has the same conductivity type as the conductivity type of the drain semiconductor portion.
- the loss of the drift semiconductor portion can be reduced. That is, when a voltage is applied so that a drain current flows through the gate semiconductor portion, the drain current controlled by the channel semiconductor portion reaches the drain semiconductor portion via the conductive semiconductor region of the drift semiconductor portion. on the other hand, When a voltage is applied such that a drain current does not flow through the good semiconductor portion, the impurity concentration and the thickness of each semiconductor region are reduced so that both the conductive semiconductor region and the non-conductive semiconductor region of the drift semiconductor portion are depleted. It has been determined and is in a state equivalent to a kind of dielectric.
- the thickness of the drift semiconductor portion can be reduced to half as compared with the case where the drift semiconductor portion has no conductive semiconductor region and non-conductive semiconductor region. Therefore, in order to realize a desired drain breakdown voltage, the impurity concentration of the conductive semiconductor region can be increased, and the thickness of the drift semiconductor portion can be reduced to half. As a result, the loss of the drift semiconductor part can be reduced.
- the drain semiconductor portion, the drift semiconductor portion, the buried semiconductor portion, and the like are formed by wide-gap semiconductor materials such as SiC and GaN. It is preferable to form each semiconductor portion such as a gate semiconductor portion, a channel semiconductor portion, a connection semiconductor portion, and a source semiconductor portion. Wide gap semiconductors have excellent characteristics as power device semiconductor materials, such as a large band gap and a high maximum dielectric breakdown strength as compared with silicon. Therefore, particularly low loss can be realized as compared with silicon.
- a method of manufacturing a vertical junction field-effect transistor includes a step of forming a first semiconductor layer of a first conductivity type on a substrate of a first conductivity type, The surface has first to fourth regions arranged in order in a predetermined axial direction, and a second conductivity type dopant is applied to the first to third regions of the main surface of the first semiconductor layer. And forming a buried semiconductor portion, and forming a second semiconductor layer of the first conductivity type on the first semiconductor layer, and forming the first conductivity type on the second semiconductor layer.
- a source semiconductor layer Forming a source semiconductor layer, etching at least a source semiconductor layer on at least one of the second, third, and fourth regions of the main surface of the first semiconductor layer so as to reach the first semiconductor layer; Exposing a predetermined region of the second semiconductor layer, the predetermined region includes: a plurality of first portions extending in a predetermined axial direction; And a second part defined to include the part Forming a first semiconductor portion of the second conductivity type by introducing a second conductivity type dopant for the gate semiconductor portion into the plurality of first portions.
- a second conductivity type dopant for a gate semiconductor portion is introduced into a second portion to form a second semiconductor portion of a second conductivity type. It is preferable that the method further includes a step of forming the second semiconductor portion, wherein the depth of the second semiconductor portion is smaller than the depth of the first semiconductor portion.
- the first semiconductor portion is formed so as to be connected to the buried semiconductor portion.
- the method for manufacturing a vertical junction field-effect transistor includes a first semiconductor layer forming step of forming a first conductive type first semiconductor layer on a first conductive type substrate,
- the main surface of the semiconductor layer has first to fourth regions arranged in order in a predetermined axial direction, and the first to third regions of the main surface of the first semiconductor layer have the second conductivity type.
- a second conductivity type dopant for the gate semiconductor portion is introduced at a predetermined depth into the second semiconductor layer on the second and third regions on the main surface of the first semiconductor layer to form the second conductivity type.
- a second semiconductor region forming step of forming a second semiconductor region repeating the second semiconductor layer forming step and the second semiconductor region step until a desired number of second semiconductor layers is obtained; Forming a channel semiconductor portion for forming a gate semiconductor portion and a channel semiconductor portion of the channel semiconductor portion.
- a second semiconductor layer of a first conductivity type having a predetermined thickness is formed on the first semiconductor layer. And forming a channel semiconductor portion by introducing a dopant of the second conductivity type such that the concentration is maximized at a predetermined depth in the second semiconductor layer, thereby forming a plurality of stacked gate semiconductor portions and a channel semiconductor portion. It is preferable to form a part.
- the first dopant and the second dopant are so formed that the concentration becomes maximum at a predetermined depth in the second semiconductor layer. It is preferable to alternately introduce these dopants to simultaneously form a plurality of stacked gate semiconductor portions and channel semiconductor portions.
- a second semiconductor connection region of the second conductivity type is formed so as to connect the insides of the second semiconductor layers to each other. It is preferable to include a connection region forming step.
- a conductive semiconductor layer of the same conductivity type as the substrate of the first conductivity type is formed. It is preferable that a non-conductive semiconductor layer of a conductivity type opposite to that of the layer is formed on the conductive semiconductor layer, and the first semiconductor layer is formed so that the conductive semiconductor layer is electrically connected to the channel semiconductor portion.
- a non-conductive semiconductor layer of the opposite conductivity type to the substrate of the first conductivity type is formed. It is preferable that a conductive semiconductor layer having a conductivity type opposite to that of the conductive semiconductor layer is formed on the non-conductive semiconductor layer, and the first semiconductor layer is formed so that the conductive semiconductor layer is electrically connected to the channel semiconductor portion. .
- the conductive semiconductor layer and the non-conductive semiconductor layer are formed in a direction intersecting the main surface of the substrate. It is preferable to form the first semiconductor layer by forming.
- the vertical junction field-effect transistor further includes a source electrode electrically connected to the source semiconductor portion and the second semiconductor portion, and the embedded semiconductor portion is connected via the second semiconductor portion. It is preferable to be electrically connected to the source electrode.
- the buried semiconductor portion and the source semiconductor portion are connected to the same source electrode. It is electrically connected.
- the capacitance between gate and drain Since the component is a capacitance component between the gate and the source, high-frequency operation is possible.
- a vertical junction field-effect transistor includes a drain semiconductor section, a drift semiconductor section, a buried semiconductor section, a channel semiconductor section, a source semiconductor section, A first gate semiconductor portion, a first gate electrode, and a source electrode.
- the drift semiconductor unit is provided on the main surface of the drain semiconductor unit, and has first, second, third, and fourth regions extending in a direction crossing the main surface.
- the buried semiconductor portion has a conductivity type opposite to that of the drift semiconductor portion, and is provided on the first, second, and fourth regions of the drift semiconductor portion.
- the channel semiconductor portion is provided along the embedded semiconductor portion on the first and second regions, has a conductivity type different from the conductivity type of the embedded semiconductor portion, and is electrically connected to the third region of the drift semiconductor portion.
- the source semiconductor section is provided on the first region of the drift semiconductor section and the channel semiconductor section.
- the first gut semiconductor section has the same conductivity type as the embedded semiconductor section, is electrically connected to the embedded semiconductor section, and is provided on the fourth region of the drift semiconductor section.
- the first gate electrode is electrically connected to the first good semiconductor part on the fourth region of the drift semiconductor part.
- the source electrode is electrically connected to the source semiconductor portion on the first region of the drift semiconductor portion, is electrically insulated from the first gate electrode on the first gate electrode, and is connected to the drift semiconductor portion. Are provided on the first, second, third and fourth regions.
- the buried semiconductor portion and the channel semiconductor portion, and the first gate electrode and the source electrode can be arranged on the drift semiconductor portion.
- the sum of the loss of the channel semiconductor portion and the loss of the drift semiconductor portion becomes the basic loss of the device. Therefore, if the breakdown voltage of the device is increased by only the channel semiconductor portion, the impurity concentration of the channel becomes lower, the channel length becomes longer, and the device loss increases. Therefore, the following effects can be obtained by providing a channel semiconductor portion for controlling the drain current and a drift semiconductor portion for bearing the breakdown voltage of the device as in the structure of the present invention.
- the channel semiconductor can increase the impurity concentration and shorten the channel length. The loss of the semiconductor part can be reduced.
- the vertical junction field-effect transistor preferably further includes a second gate semiconductor unit.
- the second gate semiconductor unit has a conductivity type opposite to that of the drain semiconductor unit, and is provided on the second region or the second and third regions of the drift semiconductor unit.
- a channel semiconductor section is provided between the first gate semiconductor section and the second gate semiconductor section.
- a second gut electrode electrically connected to the second gate semiconductor unit and electrically insulated below the source electrode is provided on the second region or the second and third regions of the drift semiconductor unit.
- the channel semiconductor portion is provided between the first buried semiconductor portion and the second good semiconductor portion, the channel semiconductor portion is controlled from both sides. Therefore, the thickness of the channel can be increased and the loss can be reduced.
- the second gate semiconductor portion is connected to the gate electrode by electrically connecting the first gate semiconductor portion and the source semiconductor portion with the source electrode.
- Feedback capacitance (capacitance between gate and drain) ⁇ mutual conductance is often used as an index indicating the operating frequency of a transistor.
- connection semiconductor portion is provided in the vertical junction field-effect transistor.
- the connection semiconductor portion has the same conductivity type as the buried semiconductor portion, penetrates the channel semiconductor portion so as to electrically connect the second gate semiconductor portion and the buried semiconductor portion, and is connected to the first portion of the drift semiconductor portion. It is scattered on the area of 2. According to this structure, the drift semiconductor portion The fourth region and the first gate semiconductor portion can be eliminated, and the device area can be reduced with the same loss.
- the vertical junction field-effect transistor further includes a first semiconductor unit.
- the first semiconductor unit is provided on the first region of the drift semiconductor unit and the channel semiconductor unit, and has the same conductivity type as the source semiconductor unit.
- the impurity concentration of the first semiconductor portion is preferably lower than the impurity concentration of the channel semiconductor portion.
- the first semiconductor portion is provided between the channel semiconductor portion and the source semiconductor portion.
- the thickness tolerance of the channel semiconductor portion accompanying the etching can be absorbed. Therefore, individual differences in the electrical characteristics of the vertical junction field effect transistor can be reduced.
- a vertical junction field-effect transistor has a structure in which at least one of the first and second gate electrodes serves as a gate electrode on the outer periphery of a basic cell (block) or a chip composed of a plurality of transistors. Provided. In the transistor having such a structure, it is preferable that the first gate semiconductor portion and the source semiconductor portion are electrically connected to each other by a source electrode. In such a vertical junction field-effect transistor, a good electrode and a source electrode can be formed at the same time, and as a result, the manufacturing process can be simplified.
- a heterojunction semiconductor material is provided as a second gate electrode so that the second gate semiconductor portion and the channel semiconductor portion form a heterojunction. May be used. According to the transistor having such a structure, the step of forming the second gate semiconductor portion is not required, and the manufacturing process is simplified.
- the thickness of the channel semiconductor portion provided on the second region of the drift semiconductor portion is equal to the thickness of the buried portion provided on the first region of the drift semiconductor portion. It is preferable that the distance be smaller than the distance between the embedded semiconductor portion and the source semiconductor portion. According to such a transistor, the buried semiconductor portion and the second gate half The conductor can be separated from the source semiconductor. As a result, the breakdown voltage between the gate and the source is improved. Further, since the distance between the channel semiconductor portion and the source semiconductor portion is set in the vertical direction, even if this distance is increased, the chip size of the transistor does not increase.
- the thickness of the channel semiconductor portion on the buried semiconductor portion or the drain semiconductor located between the buried semiconductor portion and the second gut semiconductor portion is determined so that the vertical junction field effect transistor exhibits normally-off characteristics.
- the thickness of the channel semiconductor portion can be determined by etching. For this reason, a channel is formed so that a depletion layer generated by a diffusion potential between each gate semiconductor part or the buried semiconductor part and the semiconductor part and the channel semiconductor part having the opposite conductivity type spreads over the entire channel semiconductor part. It becomes easy to reduce the impurity concentration and the thickness of the semiconductor portion. Therefore, even if no gate voltage is applied, the channel semiconductor portion can be depleted, and a normally-off transistor can be realized.
- the channel semiconductor portion has a structure in which low-concentration layers and high-concentration layers are alternately stacked.
- the drift semiconductor portion of the vertical junction field effect transistor extends along a reference plane intersecting the main surface of the drain semiconductor portion and has the same conductivity type as the drain semiconductor portion.
- the conductive semiconductor region, the non-conductive semiconductor region, and the first to fourth regions of the power drift semiconductor portion are formed in the same direction as the direction in which the first to fourth regions are arranged or in the direction intersecting with the direction.
- the loss of the drift semiconductor portion can be reduced. That is, when a voltage is applied so that a drain current flows through the gate semiconductor portion, the drain current controlled by the channel semiconductor portion reaches the drain semiconductor portion via the conductive semiconductor region of the drift semiconductor portion. On the other hand, when a voltage is applied so that the drain current does not flow through the good semiconductor portion, the impurity concentration and the thickness of each semiconductor region are so set that both the conductive semiconductor region and the non-conductive semiconductor region of the drift semiconductor portion are depleted. Is determined, and it becomes a state equivalent to a kind of dielectric.
- the thickness of the drift semiconductor portion can be reduced to half as compared with the case where the drift semiconductor portion has no conductive semiconductor region and non-conductive semiconductor region. Therefore, to achieve a desired drain breakdown voltage, the impurity concentration of the conductive semiconductor region can be increased, and the thickness of the drift semiconductor portion can be reduced to half. As a result, the loss of the drift semiconductor portion is reduced.
- the drain semiconductor portion, the drift semiconductor portion, and the first gate are formed by a wide-gap semiconductor material such as SiC or GaN. It is preferable to form each semiconductor portion such as a semiconductor portion and a channel semiconductor portion. Wide gap semiconductors have excellent characteristics as power device semiconductor materials, such as a large band gap and a high maximum dielectric breakdown strength compared to silicon. Therefore, a low loss can be realized especially as compared with silicon.
- a drift semiconductor layer having first, second, third, and fourth regions is formed on a substrate of a first conductivity type. Forming the drift semiconductor layer in the first, second, and fourth regions of the drift semiconductor layer. A step of forming a buried semiconductor portion by introducing an impurity having a conductivity type opposite to the conductivity type, and a channel semiconductor having a conductivity type different from the conductivity type of the buried semiconductor portion on the buried semiconductor portion and the drift semiconductor layer. Forming a source portion on the first region of the drift semiconductor layer; and forming a portion of the drift semiconductor layer on the fourth region having the same conductivity type as that of the buried semiconductor portion.
- the second region or the second and third regions of the drift semiconductor layer are formed before the step of forming the first gate semiconductor portion. Further comprising the step of introducing an impurity having the same conductivity type as the first gate semiconductor portion to form a second gate semiconductor portion, wherein the second gate semiconductor portion is electrically connected to the second gate semiconductor portion.
- the second gate electrode is formed in a step of forming the first gut electrode.
- a method of manufacturing a vertical junction field-effect transistor includes forming a drift semiconductor layer having first, second, third, and fourth regions on a substrate of a first conductivity type. Forming a buried semiconductor portion by introducing an impurity having a conductivity type opposite to that of the drift semiconductor layer into the first, second, and fourth regions of the drift semiconductor layer; Forming a channel semiconductor portion having a conductivity type different from the conductivity type of the buried semiconductor portion on the drift semiconductor layer; forming a source semiconductor portion on the first region of the drift semiconductor layer; Introducing a dopant having the same conductivity type as the buried semiconductor portion into the second region or the second and third regions of the layer to form a second gate semiconductor portion; Embedded semi-conductor on part of the fourth area of the layer By introducing part of the conductivity type the same conductivity type as consisting impurity, and forming a first gate semiconductor portion, which is electrically connected to the second gate one bets semiconductor portion
- the method preferably includes a step of forming forming
- a drift semiconductor layer having first, second, third, and fourth regions is formed on a substrate of a first conductivity type.
- Forming a buried semiconductor portion by introducing impurities having a conductivity type opposite to that of the drift semiconductor layer into the first, second, and fourth regions of the drift semiconductor layer;
- Embedded in a part of the second region of the semiconductor layer Forming a connection semiconductor portion for electrically connecting the buried semiconductor portion and the second gate semiconductor portion by introducing an impurity having the same conductivity type as the conductivity type of the conductor portion; and Forming a second good electrode electrically connected to the
- the method of manufacturing the vertical junction field effect transistor prior to the step of forming the source semiconductor portion, a first semiconductor having the same conductivity type as the source semiconductor portion on the channel semiconductor portion is provided.
- the method further includes a step of forming a semiconductor portion, wherein the impurity concentration of the first semiconductor portion is preferably lower than the impurity concentration of the channel semiconductor portion.
- a step of forming a drift semiconductor layer includes forming a conductive semiconductor layer having the same conductivity type as a drain semiconductor portion, and forming a conductive semiconductor layer opposite to the conductive semiconductor layer.
- the non-conductive semiconductor layer is formed in the conductive semiconductor layer, and the drift semiconductor layer is formed so that the conductive semiconductor layer is electrically connected to the channel semiconductor portion.
- a method for manufacturing a vertical junction field-effect transistor is as follows. In the step of forming a drift semiconductor layer, a drift semiconductor portion and a non-conductive semiconductor layer of the opposite conductivity type are formed; It is preferable that a conductive semiconductor layer of a conductivity type opposite to that of the nonconductive semiconductor layer is formed in the nonconductive semiconductor layer, and the drift semiconductor layer is formed so that the conductive semiconductor layer is electrically connected to the channel semiconductor portion. .
- FIG. 1A is a perspective view of a vertical J FET according to the first embodiment.
- Figure 1B shows
- FIG. 2 is a cross-sectional view of the vertical J FET according to the first embodiment, taken along the line II.
- FIG. 2A is a perspective view in a drain semiconductor film forming step.
- FIG. 2B is a perspective view in a drift semiconductor film forming step.
- FIG. 2C is a perspective view showing a step of forming a buried semiconductor portion.
- FIG. 3A is a perspective view in a channel semiconductor film forming step.
- FIG. 3B is a perspective view in a source semiconductor film forming step.
- FIG. 4A is a perspective view in a source semiconductor part forming step.
- FIG. 4B is a perspective view in the step of forming the p + type semiconductor region.
- FIG. 5A is a perspective view in the step of forming the p + type semiconductor portion.
- FIG. 5B is a perspective view in the thermal oxidation step.
- FIG. 6A is a perspective view in an opening forming step.
- FIG. 6B is a perspective view in an electrode forming step.
- FIG. 7A is a perspective view showing a shallow concave portion forming step.
- FIG. 7B is a perspective view showing a deep concave portion forming step.
- FIG. 8 is a perspective view in a gate semiconductor part forming step.
- FIG. 9 is a perspective view of a vertical JFET according to the fourth embodiment.
- FIG. 10 is a perspective view of a vertical JFET according to the fourth embodiment.
- FIG. 11A is a perspective view in a step of forming a p + type semiconductor film.
- FIG. 11B is a perspective view in a source semiconductor film forming step.
- FIG. 11C is a perspective view of the step of forming the p + type semiconductor portion.
- FIG. 12 is a perspective view of a vertical JFET according to the sixth embodiment.
- FIG. 13A is a perspective view of a vertical JFET according to the seventh embodiment.
- FIG. 13B is a cross-sectional view of the vertical JFET of the seventh embodiment, taken along the line II-II.
- FIG. 14A is a perspective view in the step of forming the p + type semiconductor layer.
- FIG. 14B is a perspective view in the step of forming the p + type connection semiconductor layer.
- FIG. 15A is a perspective view of the step of forming the p + type gate semiconductor portion.
- FIG. 15B is a perspective view in the step of forming the p + -type gut semiconductor portion.
- FIG. 16A is a perspective view showing a channel semiconductor film forming step.
- FIG. 16B is a perspective view of the source semiconductor film forming step.
- FIG. 17A is a perspective view showing a source semiconductor part forming step.
- FIG. 17B is a perspective view of the thermal oxidation step.
- FIG. 18A is a perspective view in an opening forming step.
- FIG. 18B is a perspective view in an electrode forming process.
- FIG. 19A is a perspective view of a vertical JFET according to the ninth embodiment.
- FIG. 19B is a cross-sectional view of the vertical JFET of the ninth embodiment, taken along the line III-III.
- FIG. 2OA is a perspective view in a second p + type semiconductor layer forming step.
- FIG. 20B is a perspective view in the step of forming the P + type connection semiconductor layer.
- FIG. 21A is a perspective view of the vertical JFET according to the first embodiment.
- FIG. 21B is a perspective view of the pulse-doped semiconductor portion of the vertical JFET in the first embodiment.
- FIG. 22A is a perspective view of a vertical type FET showing another embodiment having a pulse dope structure.
- FIG. 22B is a perspective view of a vertical J FET showing still another form having a pulse dope structure.
- FIG. 23 is a perspective view of a vertical JFET according to the 12th embodiment.
- FIG. 24A is a perspective view of a vertical JFET according to the twelfth embodiment.
- FIG. 24B is a perspective view of the vertical JFET in the 12th embodiment.
- FIG. 25 is a sectional view of a vertical JFET according to the thirteenth embodiment.
- FIG. 26 is a cross-sectional view of a vertical JFET showing another mode having a super junction structure.
- FIG. 27 is a cross-sectional view of a vertical JFET showing yet another mode having a super junction structure.
- FIG. 28A is a schematic diagram showing a positional relationship between a semiconductor region of a vertical JFET and a gut semiconductor portion in the fourteenth embodiment.
- FIG. 28B is a schematic diagram showing a vertical JFET according to the thirteenth embodiment.
- FIG. 28C is a schematic diagram showing a vertical JFET according to still another embodiment.
- FIG. 29A is a perspective view of a vertical JFET in a drift region forming step.
- FIG. 29B is a perspective view of the vertical J FET in the p + type semiconductor region forming step.
- FIG. 29C is a perspective view of the vertical J FET in the source region forming step.
- FIG. 30 is a cross-sectional view of the vertical J FET according to the sixteenth embodiment.
- FIG. 31A is a cross-sectional view of the step of forming the drain semiconductor film.
- FIG. 31B is a cross-sectional view of the drift semiconductor film forming step.
- FIG. 31C is a cross-sectional view of the Good semiconductor part forming step.
- FIG. 32A is a cross-sectional view in a step of forming a channel semiconductor film.
- FIG. 32B is a cross-sectional view of the source semiconductor film forming step.
- FIG. 32C is a cross-sectional view of the step of forming the source semiconductor unit.
- FIG. 33A is a cross-sectional view in a step of forming the p + -type gate semiconductor portion.
- FIG. 33B is a cross-sectional view of the thermal oxidation step.
- FIG. 33C is a sectional view of the opening forming step.
- FIG. 34A is a cross-sectional view in a gate electrode formation step.
- FIG. 34B is a sectional view of the insulating film forming step.
- FIG. 34C is a cross-sectional view of the step of forming the opening.
- FIG. 35 is a cross-sectional view in a source electrode forming step.
- FIG. 36 is a cross-sectional view of the vertical J FET according to the eighteenth embodiment.
- FIG. 37A is a cross-sectional view in a step of forming a channel semiconductor film.
- Figure 37B shows FIG. 6 is a cross-sectional view in a step of forming an n-type semiconductor film.
- FIG. 37C is a cross-sectional view of a step of forming the source semiconductor unit.
- FIG. 38 is a perspective view of a vertical JFET according to the twentieth embodiment.
- FIG. 39 is a cross-sectional view of the vertical JFET according to the twenty-first embodiment.
- FIG. 4OA is a cross-sectional view in the step of forming the p + type gate semiconductor portion.
- FIG. 40B is a cross-sectional view after the p + -type gut semiconductor portion is formed.
- FIG. 41 is a cross-sectional view of a vertical JFET according to the second embodiment.
- FIG. 42A is a cross-sectional view of the vertical JFET according to the twenty-fourth embodiment.
- Fig. 4 2 is a cross-sectional view of the vertical JFET according to the twenty-fourth embodiment.
- B is a cross-sectional view of the vertical JFET of the twenty-fourth embodiment, taken along the line IV-IV.
- FIG. 43A is a sectional view of a vertical JFET according to the twenty-fifth embodiment.
- FIG. 43B is a cross-sectional view of the pulse-doped semiconductor portion of the vertical JFET in the twenty-fifth embodiment.
- FIG. 44 is a cross-sectional view of the vertical JFET according to the twenty-sixth embodiment.
- FIG. 45 is a cross-sectional view of a vertical JFET showing another embodiment having a super junction structure.
- FIG. 46 is a cross-sectional view of a vertical JFET showing still another mode having a super-joined structure.
- FIG. 47A is a schematic diagram showing a positional relationship between a semiconductor region of a vertical JFET and a gate semiconductor portion in the twenty-seventh embodiment.
- FIG. 47B is a schematic diagram showing a vertical J FET in the twenty-seventh embodiment.
- FIG. 47C is a schematic diagram showing a vertical JFET according to still another embodiment.
- FIG. 48A is a perspective view of a vertical JFET in a drift region forming step.
- FIG. 48B is a perspective view of the vertical JFET in the step of forming the p + -type semiconductor region.
- FIG. 48C is a perspective view of the vertical JFET in the source region forming step.
- FIG. 1A is a perspective view of a vertical J FE Tla according to a first embodiment.
- the vertical JFET la is composed of an n + -type drain semiconductor section 2, an n-type drift semiconductor section 3, a p + -type buried semiconductor section 4, and an n-type channel semiconductor section 5. And an n + type source semiconductor section 7 and a p + type gate semiconductor section 8.
- the vertical JFET 1a has a vertical structure in which majority carriers move in a direction from one surface to the other surface of the element (hereinafter, referred to as "current direction").
- Figure 1A shows the coordinate system. These coordinates are specified so that the current direction of the JFET is aligned with the y-axis.
- the n + -type drain semiconductor unit 2 has a pair of opposing surfaces. Further, the n + -type drain semiconductor portion 2 can be a substrate to which a dopant is added. In a preferred embodiment, the substrate is formed of SiC (silicon carbide). As dopants added to SiC, donor impurities such as N (nitrogen), P (phosphorus), and As (arsenic), which are elements of Group 5 of the periodic table, can be used.
- the n + -type drain semiconductor portion 2 has a drain electrode 2 a on one (back surface) of a pair of surfaces. The drain electrode 2a is formed of a metal.
- the n-type drift semiconductor portion 3 is provided on the other (front surface) of the pair of surfaces of the n + -type drain semiconductor portion 2.
- the n-type drift semiconductor unit 3 has first to fourth regions 3a, 3b, 3c, 3d arranged in the y-axis direction on the surface thereof.
- Each of the first to fourth regions 3a, 3b, 3c, 3d extends in a predetermined axial direction ((-axis direction in FIG. 1), and in a preferred embodiment, a rectangular region It is.
- a p + type embedded semiconductor unit 4 is provided on the first, second, and third regions 3a, 3b, and 3c. No.
- the channel semiconductor section 5 is provided on the region 3d of FIG.
- the conductivity type of the drift semiconductor portion 3 is the same as the conductivity type of the drain semiconductor portion 2, and the dopant concentration of the drift semiconductor portion 3 is lower than the dopant concentration of the drain semiconductor portion 2.
- the drift semiconductor section 3 is formed of SiC (silicon carbide) to which a dopant is added.
- the p + type embedded semiconductor unit 4 is provided on the first, second, and third regions 3a, 3b, and 3c.
- the conductivity type of the buried semiconductor portion 4 is opposite to the conductivity type of the drift semiconductor portion 3.
- the buried semiconductor section 4 has a higher p-type dopant concentration than the drift semiconductor section 3 has an n-type dopant concentration.
- the p + type buried semiconductor portion 4 is formed of SiC (silicon carbide) to which a dopant is added.
- acceptor impurities such as B (boron) and A 1 (aluminum), which are elements of Group 3 of the periodic table, can be used.
- the n-type channel semiconductor portion 5 is formed on the first to third regions 3a, 3b, 3c and the p + type buried semiconductor portion 4 and on the fourth region 3d. Is provided.
- the n-type channel semiconductor portion 5 extends in a predetermined axial direction (the y-axis direction in FIG. 1A) along the p + -type embedded semiconductor portion 4.
- the n-type channel semiconductor section 5 is electrically connected to the n-type drift semiconductor section 3 in the fourth region 3d. Since the conductivity type of the channel semiconductor portion 5 is opposite to the conductivity type of the buried semiconductor portion 4, a pn junction is formed at the interface between the buried semiconductor portion 4 and the channel semiconductor portion 5.
- the dopant concentration of the n-type channel semiconductor portion 5 is lower than the dopant concentration of the n + -type drain semiconductor portion 2.
- the n- type channel semiconductor section 5 is formed of SiC to which a dopant is added.
- the n + -type source semiconductor unit 7 is provided on the first region 3a and the n-type channel semiconductor unit 5.
- the source semiconductor portion 7 has the same conductivity type as the conductivity type of the drain semiconductor portion 2.
- the source semiconductor section 7 is connected to the drift semiconductor section 3 via the channel semiconductor section 5.
- a source electrode 7a is provided on the n + type source semiconductor section 7,
- Source electrode 7a is formed of metal.
- An insulating film 9 serving as a silicon oxide film is provided on the n- type source semiconductor unit 7, and the n- type source semiconductor unit 7 is connected to the source electrode 7 a via an opening of the insulating film 9.
- the p + type gate semiconductor unit 8 is provided on the third and fourth regions 3c and 3d and the channel semiconductor unit 5 as shown in FIG. 1B.
- the p + type gate semiconductor portion 8 has convex portions 8b, 8c, 8d extending from the third region 3c toward the fourth region 3d (y-axis direction in the figure).
- the protrusions 8 b, 8 c, and 8 d extend to reach the embedded semiconductor section 4.
- the protrusions 8b, 8c, 8d are electrically connected to the embedded semiconductor unit 4 on the third region 3c.
- An n-type channel semiconductor portion 5 is provided between the convex portions 8b, 8c, 8d.
- the conductivity type of the good semiconductor portion 8 is opposite to the conductivity type of the channel semiconductor portion 5, a pn junction is formed at the interface between the gate semiconductor portion 8 and the channel semiconductor portion 5.
- the drain current flowing through the n-type channel semiconductor section 5 is controlled by the P + type buried semiconductor section 4 and the p + type gate semiconductor section 8.
- the p-type dopant concentration of the gate semiconductor section 8 is higher than the n-type dopant concentration of the channel semiconductor section 5.
- the p + type gate semiconductor section 8 is formed of SiC to which a dopant is added.
- the channel length (in the y-axis direction in the figure) is greater than 10 times the channel thickness (in the z-axis direction in the figure).
- a gate electrode 8 a is provided on the surface of the p + -type gate semiconductor unit 8.
- Gate electrode 8a is formed of metal.
- Source electrode 7a is formed of metal.
- An insulating film 9, such as a silicon oxide film, is provided on the p + type gate semiconductor portion 8, and the p + type gate semiconductor portion 8 is connected to the gate electrode 8a through the opening of the insulating film 9. I have.
- Arrow e indicates a path of a current flowing from the source semiconductor unit 7 to the drain semiconductor unit 2. (Second Embodiment) Next, a method of manufacturing the vertical JFET 1a will be described. 2A to 2C, 3A and 3B, 4A and 4B, 5A and 5
- FIG. 5B, FIG. 6A and FIG. 6B, FIG. 7A and FIG. It is a perspective view which shows the manufacturing process of type
- a substrate is prepared as shown in FIG. 2A.
- an n + type SiC semiconductor substrate is exemplified.
- the dopant concentration of the substrate is so high that the substrate can be used as the drain semiconductor portion 2.
- a SiC film 3 is formed on the surface of the n + type drain semiconductor portion 2 by an epitaxy growth method.
- the thickness T 1 of the S i C film 3 is, for example, ⁇ ⁇ .
- the conductivity type of the SiC film 3 is the same as the conductivity type of the n + type drain semiconductor portion 2.
- the dopant concentration of the SiC film 3 is lower than the dopant concentration of the n + -type drain semiconductor portion 2.
- Dopant DOO concentration of S i C film 3 is, for example, about 1 X 10 16 Zc m 3. From the S i C film 3, an n-type drift semiconductor portion is formed.
- a step of forming an embedded semiconductor part will be described with reference to FIG. 2C.
- a mask M1 having a pattern extending in a predetermined axial direction (X-axis direction in the figure) is formed.
- a dopant A1 is selectively ion-implanted into a region 3e formed on the SiC film 3 to form a P + type buried semiconductor portion 4 having a predetermined depth.
- the depth D 1 of the p + type embedded semiconductor section 4 is, for example, about 1.2 / m.
- the dopant concentration of the p + type buried semiconductor section 4 is, for example, about 1 ⁇ 10 / cm 3 .
- a SiC film 5 is formed on the surface of the p + type buried semiconductor part 4 and the SiC film 3 by an epitaxy method. I do.
- the thickness T 2 of the S i C film 5 is, for example, about 0.
- the conductivity type of the SiC film 5 is the same as the conductivity type of the drain semiconductor unit 2.
- the dopant concentration of the SiC film 5 is lower than the dopant concentration of the drain semiconductor portion 2.
- the dopant concentration of the SiC film 5 is, for example, about 1 ⁇ 10 17 / cm 3 .
- the S i C film 5 forms an n-type channel semiconductor portion.
- the n-type drift Although a single SiC film is formed for the semiconductor portion and the n-type channel semiconductor portion, the SiC film is repeatedly formed for each of the drift semiconductor portion and the channel semiconductor portion. A plurality of film forming steps may be included. In addition, a desired dopant concentration profile can be employed for the SiC film so as to function as a three-diffusion film and three drift semiconductor portions and a channel semiconductor portion.
- an S i C film 7 for an n + type source semiconductor portion is formed on the surface of the S i C film 5 by an epitaxial growth method.
- the thickness ⁇ 3 of the SiC film 7 is, for example, about 0.2 m.
- the conductivity type of the SiC film 7 is the same as the conductivity type of the drain semiconductor unit 2. Further, the dopant concentration of the SiC film 7 is higher than the dopant concentration of the SiC film 5.
- a step of forming a source semiconductor part will be described with reference to FIG. 4A.
- a mask M2 having a pattern extending in a predetermined axial direction (X-axis direction in the figure) is formed.
- the n + type source film 7 and the SiC film 5 are selectively etched.
- the portion of the n + type source layer 7 and the S i C film 5 covered with the mask M2 remains without being etched, and a semiconductor portion for the n + type source semiconductor portion is formed.
- the mask M2 is removed.
- a step of forming a p + -type semiconductor region will be described with reference to FIG. 4B.
- a mask M3 having a pattern of a predetermined shape is formed.
- the dopant A 2 is selectively ion-implanted into the regions 5 a, 5 b, and 5 c defined on the S iC film 5 by the mask M 3, and the p + -type semiconductor regions 81, Form 82 and 83.
- the dopant concentration of the p + -type semiconductor regions 81, 82, and 83 is, for example, about 1 ⁇ 10 18 / cm 3 .
- P + -Type Semiconductor Part Forming Step A step of forming a p + -type semiconductor part will be described with reference to FIG. 5A.
- the mask A has a predetermined depth by selectively ion-implanting the dopant A3 into a region defined on the SiC film 5 by the mask M4 (for example, the regions 5a to 5e including the regions 5a to 5c).
- P + type semiconductor layers 84 and 85 are formed.
- the dopant concentration of the p + type semiconductor layers 84 and 85 is, for example, about 1 ⁇ 10 18 / cm 3 .
- the concentration near the surface is about 1 ⁇ 10 19 to 1 ⁇ 10 2 ° cm 3 .
- the mask M4 is removed. Note that the order of performing the p + type semiconductor layer forming step and the p + type semiconductor portion forming step is interchangeable.
- Thermal Oxidation Step The step of thermally oxidizing the vertical JFET 1a will be described with reference to FIG. 5B. Thermal oxidation is applied to the vertical JFET 1a. Thermal oxidation treatment, the exposure of the S i C in an oxidizing atmosphere at high temperatures (e.g., about 1 200 ° C), silicon and oxygen chemically reacts silicon oxide film in the semiconductor unit (S i 0 2) is formed Is done. As a result, the surface of each semiconductor portion is covered with oxide film 9.
- high temperatures e.g., about 1 200 ° C
- a step of forming an opening for forming a source electrode and a gate electrode will be described with reference to FIG. 6A.
- the oxide film 9 is selectively etched to form openings 9a and 9b.
- the surface portions of the source semiconductor section 7 and the gate semiconductor section 8 are respectively exposed. These exposed portions serve as conductive portions to the source electrode and the gate electrode, respectively.
- the resist mask is removed.
- Electrode Forming Step A step of forming an electrode will be described with reference to FIG. 6B.
- a metal film for an ohmic contact electrode for example, nickel (Ni) is deposited on the surface of the vertical JFET 1a.
- a photoresist mask is formed so that Ni is left only in the source electrode opening 9a and the gut electrode opening 9b, and the Ni metal film is etched to remove the resist.
- heat treatment is performed in an atmosphere of an inert gas such as nitrogen or argon at a high temperature (for example, about 1000 ° C. for Ni) to form an ohmic contact.
- Materials for the metal film for the ohmic contact electrode include Ni, tungsten (W), and titanium (Ti). It is not limited to these.
- a metal film for electrodes such as aluminum (A1) is deposited.
- a photoresist mask having a predetermined shape is formed.
- the metal film for the electrode is selectively etched.
- the material of the electrode metal film may be, but is not limited to, aluminum alloy, copper (Cu), and tungsten (W).
- the vertical JFET 1a shown in the first embodiment was completed.
- the p + -type buried semiconductor section 4 and the p + -type gate semiconductor section 8 can be arranged on the n-type drift semiconductor section 3. Therefore, a desired drain withstand voltage can be obtained by increasing the thickness of the n-type drift semiconductor section 3 without increasing the chip size. Therefore, the breakdown voltage between the source and the drain can be improved.
- carriers flow not only below the n-type channel semiconductor section 5 but also to the n-type drift semiconductor section 3 located below the p + -type embedded semiconductor section 4. Therefore, the on-resistance can be reduced while maintaining the withstand voltage. In other words, this structure is suitable for a high breakdown voltage JFET.
- the vertical JFET 1a has an n-type channel semiconductor section 5 provided between a p + -type buried semiconductor section 4 and a p + -type gate semiconductor section 8, and a p + -type gate semiconductor section.
- the n-type channel semiconductor portion 5 is also provided between the eight convex portions. According to this structure, the width of the controllable channel is increased as compared with the case where the channel is controlled from one side of the n-type channel semiconductor unit 5. If the distance A between the p + type buried semiconductor part 4 and the p + type gut semiconductor part 8 is wider than the distance B between the convex parts of the p + type gate semiconductor part 8, the vertical JFET The threshold of 1a is determined.
- the drain, source, and gate semiconductor portions are formed of SiC.
- SiC has the following advantages over semiconductors such as Si (silicon) and GaAs (gallium arsenide).
- the device has a high melting point and a large band gap (forbidden band width), which facilitates high-temperature operation of the device.
- the insulation breakdown electric field is large, a high breakdown voltage can be achieved.
- the thermal conductivity is high, there is an advantage that large current and low loss can be easily achieved.
- the present embodiment is different from the second embodiment in the p + -type semiconductor layer forming step and the p + -type semiconductor portion forming step of the vertical JFET la. Construction method. That is, in the second embodiment, the gate semiconductor portion 8 is formed by the ion implantation method. However, in the present embodiment, the gate semiconductor portion 8 is formed through the following steps. The steps other than the p + -type semiconductor layer forming step and the p + -type semiconductor portion forming step are not described or illustrated. The same components as those in the second embodiment are denoted by the same reference numerals.
- Step of forming shallow concave portion With reference to Fig. 7A, a step of forming a shallow concave portion in the n-type semiconductor layer 5 will be described.
- the shallow concave portion forming step is performed subsequently to the source semiconductor part forming step of the second embodiment.
- a photoresist mask M5 having a pattern of a predetermined shape is formed.
- the n-type semiconductor layer 5 is selectively etched using the mask M5.
- the etching depth D 5 is such that it reaches the p + type embedded semiconductor portion 4.
- the portion of the n-type semiconductor layer 5 covered with the resist pattern remains without being etched, and a shallow concave portion is formed.
- the mask M5 is removed.
- a step of forming a deep recess in the n-type semiconductor layer 5 will be described.
- a photoresist mask M6 having a pattern of a predetermined shape is formed.
- the n-type semiconductor layer 5 is selectively etched.
- the etching depth D 6 is such that it reaches the p + type embedded semiconductor portion 4.
- the portion of the n-type semiconductor layer 5 covered with the resist pattern is etched.
- a stripe-shaped deep concave portion extending in a predetermined axial direction (y-axis direction in the figure) is formed. After forming the deep recess, the mask M6 is removed.
- Step of forming gate semiconductor unit a step of forming the gut semiconductor unit will be described.
- Polysilicon is deposited on the surfaces of the n-type drift semiconductor layer 3, the p + -type buried semiconductor layer 4, and the n-type semiconductor layer 5, and a polysilicon semiconductor portion 8 is formed in the shallow concave portion and the deep concave portion.
- the polysilicon film is grown by, for example, thermally decomposing SiH 4 (silane) using a chemical vapor deposition method.
- the conductivity type of the polysilicon semiconductor portion 8 is opposite to the conductivity type of the drain semiconductor portion 2.
- the dopant concentration of the polysilicon semiconductor portion 8 is higher than the dopant concentration of the n-type semiconductor layer 5. Subsequent to the gate semiconductor part formation step, steps subsequent to the thermal oxidation step are performed. According to the manufacturing method shown in the third embodiment, the channel semiconductor portion and the gate semiconductor portion can be formed by a hetero junction.
- FIG. 9 is a perspective view of a vertical JFET 1c according to the fourth embodiment. That is, the vertical J FET 1 c according to the fourth embodiment includes the p + -type semiconductor unit 6 on the fifth region 3 e and the p + -type embedded semiconductor unit 4 .
- FIG. 10 is a perspective view of a vertical J FET 1d according to the fifth embodiment. That is, the vertical type in still another embodiment
- J FET 1 d includes a p + type semiconductor section 6 on the fifth region 3 e and the p + type embedded semiconductor section 4.
- the n-type drift semiconductor portion 3 has first to fifth regions 3e, 3a, 3b, 3 arranged in the y-axis direction on the surface thereof. c, 3 d.
- the p + type semiconductor section 6 is provided on the fifth region 3 e and the p + type embedded semiconductor section 4.
- the p + -type semiconductor section 6 extends along the n-type channel semiconductor section 5 (see Middle z-axis direction).
- the conductivity type of the semiconductor section 6 is opposite to the conductivity type of the channel semiconductor section 5.
- the p-type dopant concentration of the semiconductor section 6 is higher than the n-type dopant concentration of the channel semiconductor section 5.
- the P + type semiconductor section 6 is formed of SiC to which a dopant is added.
- the p + -type embedded semiconductor unit 4 is electrically connected to the electrode 6a via the p + -type semiconductor unit 6. You. When the electrode 6a is used as a good electrode, a channel semiconductor portion is also formed between the P + type semiconductor portion and the P + type buried semiconductor portion. Therefore, more current can flow, and the loss is reduced.
- the p + type embedded semiconductor is connected to the source electrode 7a by connecting the p + type semiconductor portion 6 instead of the electrode 6a.
- the structure may be such that the part 4 and the source semiconductor part 7 are electrically connected to the same source electrode 7a.
- the p + type buried semiconductor section 4 has the same potential as the source semiconductor section 7.
- the capacitance formed between the P + type buried semiconductor portion and the drain semiconductor portion changes from the capacitance between the gate and the drain to the capacitance between the gate and the source, enabling high-frequency operation.
- FIGS. 11A to 11C a fifth embodiment, which is a modification of the second embodiment, will be described with reference to FIGS. 11A to 11C.
- the same components as those in the method of manufacturing the vertical JFET 1a described in the second embodiment are denoted by the same reference numerals. .
- steps after the p + type semiconductor film forming step different from the second embodiment will be described.
- P + -Type Semiconductor Film Forming Step A step of forming a p + -type semiconductor film will be described with reference to FIG. 11A.
- the p + type semiconductor film forming step is performed subsequent to the channel semiconductor film forming step.
- a mask M7 having a pattern of a predetermined shape is formed.
- the dopant A4 is selectively ion-implanted into the region 51a formed on the SiC film 51 to form the p + type semiconductor layer 61.
- S i C film 5 The thickness T4 of 1 is such a thickness that a ⁇ + type semiconductor layer 61 reaching the ⁇ + type gut semiconductor portion 4 can be formed by ion implantation.
- the dopant concentration of the ⁇ + type semiconductor layer 61 is almost the same as that of the ⁇ + type gate semiconductor portion 4.
- the mask # 7 is removed.
- the channel semiconductor film forming step and the ⁇ + type semiconductor film forming step are repeatedly performed until the channel semiconductor film and the ⁇ + type semiconductor film have a predetermined thickness.
- the S An iC film 7 is formed on the ⁇ -type semiconductor layer 5 and the ⁇ + -type semiconductor layer 6, the S An iC film 7 is formed.
- the conductivity type of the SiC film 7 is the same as the conductivity type of the n + type drain semiconductor unit 2. Further, the dopant concentration of the SiC film 7 is higher than the dopant concentration of the SiC film 5.
- FIG. 11C A step of forming the p + type semiconductor part will be described with reference to Fig. 11C.
- a mask M8 having a pattern of a predetermined shape is formed.
- the dopant A5 is selectively ion-implanted into the region 7a formed on the SiC film 7 to form the p + type semiconductor portion 6.
- the mask M8 is removed.
- a source semiconductor portion forming step is performed.
- the steps after the p + type semiconductor film forming step different from the second embodiment have been described. Other steps are the same as those in the second embodiment, but are not limited thereto.
- FIG. 12 is a perspective view of a vertical JFET 1 e according to the sixth embodiment. That is, in the fourth embodiment, the n-type channel semiconductor section 5 is configured to be in contact with the n + type source semiconductor section 7 on the first region 3a. On the other hand, in the sixth embodiment, the vertical J FET 1 e is connected between the n-type channel semiconductor section 5 and the n +
- the P + type gate semiconductor section 4 and the n-type semiconductor section 10 This is particularly suitable for a form in which the distance between them is smaller than the distance between the protrusions of the p + -type gate semiconductor portion 8.
- the n-type semiconductor unit 10 is provided on the first and second regions 3a, 3b, 3c, 3d and the n-type channel semiconductor unit 5.
- the conductivity type of the semiconductor section 10 is the same as the conductivity type of the channel semiconductor section 5.
- the n-type dopant concentration of the semiconductor section 10 is lower than the n-type dopant concentration of the channel semiconductor section 5.
- the dopant concentration of the n-type semiconductor section 10 is, for example, about 1 ⁇ 10 16 Zcm 3 .
- the n -type semiconductor portion 10 is formed of SiC (silicon carbide) to which a dopant is added.
- the n-type channel semiconductor portion 5 is not etched, so that the thickness of the channel semiconductor portion is not affected by the variation due to the etching process. Therefore, individual differences in the electrical characteristics of the vertical J FET 1 e can be reduced.
- the p + -type buried semiconductor portion 4 is connected to the source electrode 7a by connecting the p + -type semiconductor portion 6 to the source electrode 7a instead of the electrode 6a.
- the structure may be such that the source semiconductor unit 7 is electrically connected to the same source electrode 7a.
- the p + type buried semiconductor section 4 has the same potential as the source semiconductor section 7, and the capacitance formed between the P + type buried semiconductor section and the drain semiconductor section is reduced by the gate High-frequency operation is possible instead of capacitance between sources.
- a seventh embodiment which is a modification of the first embodiment, will be described with reference to FIG. 13A.
- the same components as those in the configuration of the vertical JFET 1f described in the first embodiment are denoted by the same reference numerals.
- the configuration of the channel semiconductor unit different from that of the first embodiment will be described.
- FIG. 13A is a perspective view of a vertical JFET 1f according to the seventh embodiment.
- the first embodiment differs from the seventh embodiment in the structure of the channel semiconductor portion.
- the vertical JFET 1 f has an n + -type drain semiconductor section 2, an n- type drift semiconductor section 3, a p + -type gate semiconductor section 4, and an n-type channel semiconductor section 5, , N + type source semiconductor section 7, p + type gate semiconductor section 81, 82, 83 and p + type connection semiconductor section 11.
- the n-type channel semiconductor unit 5 has n-type channel semiconductor regions 51, 52, and 53.
- the n-type channel semiconductor region 51 is provided on the second to fourth regions 3 b, 3 c, 3 d and the p + -type gate semiconductor unit 4 of the n-type drift semiconductor unit 3.
- n-type channel semiconductor region 5 1, p + -type gate semiconductor part 4 and the p + -type Gut between the semiconductor portion 8 1, p + -type gate semiconductor part 81, 82 and between the p + -type gate semiconductor part 8, It is provided between 2, 83.
- the n-type channel semiconductor region 52 is provided on the fifth region 3 e of the n-type drift semiconductor unit 3, and is connected to the n- type drift semiconductor unit 3 in the fifth region 3 e.
- the n-type channel semiconductor region 53 is provided on the first region 3 a of the n-type drift semiconductor unit 3.
- the n-type channel semiconductor region 53 is connected to the n-type channel semiconductor region 52 via the n-type channel semiconductor region 51.
- the dopant concentration of the n-type channel semiconductor portion 5 is lower than the dopant concentration of the n + type drain semiconductor portion 2.
- the n-type channel semiconductor portion 5 is formed of SiC to which a dopant is added.
- the p + type gate semiconductor portions 81, 82, and 83 are provided on the second to fourth regions 3b to 3d.
- An n-type channel semiconductor region 51 is provided between the p + -type gate semiconductor portions 81, 82, and 83. Since the conductivity types of the gate semiconductor portions 81, 82, 83 and the gate semiconductor portion 4 are opposite to those of the channel semiconductor region 51, the gate semiconductor portions 81, 82, 83, 4 and the channel semiconductor region At the interface with 51, a pn junction is formed.
- the drain current flowing through the n-type channel semiconductor region 51 is controlled by the P + type gate semiconductor portions 81, 82, 83, and 4.
- the p-type dopant concentration of the gate semiconductor portions 81, 82, 83, and 4 depends on the channel semiconductor region 5 Higher than 1 n-type dopant concentration.
- the P + type gate semiconductor portions 81, 82, 83, 4 are formed of SiC to which a dopant is added.
- a gate electrode 8a is provided on the surface of the p + type gate semiconductor section 83.
- the gate electrode 8a is formed of a metal.
- An insulating film 9 such as a silicon oxide film is provided on the p + -type gate semiconductor unit 83, and the p + -type gate semiconductor unit 83 is connected to the good electrode 8 a via an opening of the insulating film 9.
- the p + type connection semiconductor portion 11 is provided on the third region 3c as shown in FIG. 13B.
- the conductivity type of the connection semiconductor portion 11 is the same as the conductivity type of the gate semiconductor portion 4.
- the p + -type connection semiconductor portion 11 extends in the vertical direction (the z-axis direction in the figure) and connects the p + -type gate semiconductor portion 4 to the p + -type gate semiconductor portions 81, 82, and 83.
- the p-type dopant concentration of the connection semiconductor portion 11 is higher than the n-type dopant concentration of the channel semiconductor region 51.
- the P + type connection semiconductor portion 11 is formed of SiC to which a dopant is added. Arrow e indicates a path of a current flowing from the source semiconductor unit 7 to the drain semiconductor unit 2.
- FIGS. 14A and 14B, FIGS. 15A and 15B, FIGS. 16A and 16B, FIGS. 17A and 17B An eighth embodiment, which is a modification of the second embodiment, will be described with reference to FIGS. 18A and 18B.
- the same components as those in the method of manufacturing the vertical JFET 1a described in the second embodiment are denoted by the same reference numerals. .
- steps after the channel semiconductor film forming step different from the second embodiment will be described.
- a step of forming a p + -type semiconductor layer will be described with reference to FIG. 14A.
- the P + type semiconductor layer forming step is performed subsequent to the channel semiconductor film forming step.
- a mask M9 having a pattern extending in a predetermined direction (X-axis direction in the figure) is formed.
- the dopant A6 is selectively ion-implanted into the region 51a defined on the SiC film 51 to form the p + type semiconductor layer 81.
- the depth D7 of the ion implantation is determined according to the threshold value of the vertical JFET.
- the mask M9 is removed.
- a step of forming a p + -type connection semiconductor layer will be described with reference to FIG. 14B.
- a mask M10 having a pattern of a predetermined shape is formed.
- the dopant A7 is selectively ion-implanted into the region 51b defined on the SiC film 51 to form the p + type connection semiconductor layer 1111.
- the depth of the ion implantation is deep enough to reach the P + type gate semiconductor portion 4.
- the dopant concentration of the p + -type connection semiconductor layer 111 is almost the same as that of the P + -type gate semiconductor portion 4.
- the mask M10 is removed.
- Step of forming p + type gate semiconductor portion A step of forming the p + type gate semiconductor portion will be described with reference to FIGS. 15A and 15B. In this step, the channel semiconductor film forming step, the p + type semiconductor layer forming step, and the p + type connecting semiconductor layer forming step are repeated, and the semiconductor layer having the p + type semiconductor layer and the p + type connecting semiconductor layer is n-type doped.
- the stacked channel portion is formed by depositing on the lift semiconductor portion 3. As a result, a semiconductor layer 5 having a predetermined thickness T5 (in the z-axis direction in the figure) is formed.
- Step of Forming Channel Semiconductor Film A step of forming an n-type channel semiconductor film will be described with reference to FIG. 16A.
- a SiC film 54 is formed on the SiC film 5 by an epitaxy growth method.
- the conductivity type of the SiC film 54 is the same as the conductivity type of the n + type drain semiconductor unit 2.
- the dopant concentration of the 31 film 54 is lower than the dopant concentration of the drain semiconductor portion 2.
- a SiC film 7 for an n + type source layer is formed on the surface of the 31 3 film 54 by an epitaxial growth method. I do.
- the conductivity type of the SiC film 7 is the same as the conductivity type of the drain semiconductor unit 2. Further, the dopant concentration of the SiC film 7 is higher than the dopant concentration of the SiC film 54.
- Step of Forming Source Semiconductor Part A step of forming the source semiconductor part will be described with reference to FIG. 17A. Pattern extending in the specified axial direction (X-axis direction in the figure) A mask M 11 having a pattern is formed.
- n + type source layer 7 and the S i C film 54 are selectively etched using the mask Ml.
- the n + type source semiconductor portion 7 and the n + type source semiconductor portion 7 are formed, while the n + type source layer 7 covered with the resist pattern and the portion 54 a of the SiCJI 54 remain without being etched.
- the mask Ml 1 is removed.
- Thermal Oxidation Step A step of thermally oxidizing the vertical JFET 1f will be described with reference to FIG. 17B.
- the vertical J FET 1 f is subjected to thermal oxidation.
- Thermal oxidation process when exposed to an oxidizing atmosphere to S i C at elevated temperature (e.g., about 1 20.0 ° C), silicon and oxygen chemically reacts silicon oxide film in the semiconductor portions (S I_ ⁇ 2) is formed Is done. As a result, the surface of each semiconductor portion is covered with oxide film 9.
- Step of Forming Opening A step of forming an opening for forming a source electrode and a gate electrode is described with reference to FIG. 18A.
- the oxide film 9 is selectively etched to form openings 9a and 9b.
- the surface portions of the source semiconductor portion 7 and the gate semiconductor portion 8 are exposed.
- the exposed portion becomes a conductive portion to the source electrode and the gate electrode.
- the resist mask is removed.
- Electrode forming step A step of forming an electrode will be described with reference to FIG. 18B.
- a metal film for an ohmic contact electrode such as nickel (Ni) is deposited on the surface of the vertical J FET 1f.
- a photoresist mask is formed so that Ni is left only in the source electrode opening 9a and the gate electrode opening 9b, the Ni metal film is etched, and the resist is removed.
- a heat treatment is performed in an atmosphere of an inert gas such as nitrogen or argon at a high temperature (for example, about 1000 ° C. for Ni) to form an ohmic contact.
- the material of the metal film for the ohmic contact electrode may be, but is not limited to, Ni, tungsten (W), titanium (Ti), and the like.
- a metal film for an electrode such as aluminum (A 1) is deposited.
- a photoresist mask having a predetermined shape is formed.
- the metal film for the electrode is selectively etched.
- the portion of the metal film for the electrode covered with the resist pattern remains without being etched, and becomes the source electrode 7a and the good electrode 8a.
- the material of the electrode metal film may be, but is not limited to, aluminum alloy, copper (Cu), or tungsten (W). After forming the electrodes, the resist mask is removed.
- the vertical JFET 1f shown in the first embodiment is completed.
- the P + -type gate semiconductor sections 81, 82, and 83 are connected to the p + -type gate semiconductor section 4 via the p + -type connection semiconductor section 11.
- both the p + type connection semiconductor section 11 and the p + type gate semiconductor sections 81, 82, 83 can be used as gates.
- the gate electrode 8a can be connected to the embedded gate semiconductor portion. Therefore, a channel region is formed between the p + -type gate semiconductor portions 4, 81, 82, and 83. Therefore, the channel region that can be controlled by the gate semiconductor portion can be increased, and the ON resistance can be reduced.
- FIG. 19A is a perspective view of a vertical J FET 1 g according to the ninth embodiment. That is, the vertical JFET 1 g in the ninth embodiment differs from the vertical JFET 1 f in that the sixth region 3 f and the P + type semiconductor portion 6 are provided on the p + type embedded semiconductor portion 4. .
- the n-type drift semiconductor portion 3 has, on its surface, first to sixth regions 3f, 3a, 3b, 3 arranged sequentially in the y-axis direction. c, 3d, and 3e.
- the p + type semiconductor section 6 is provided on the sixth region 3 f and the p + type embedded semiconductor section 4.
- the p + type semiconductor section 6 extends along the n + type source semiconductor section 7 (in the X-axis direction in the figure).
- the conductivity type of the p + -type semiconductor portion 6 is opposite to the conductivity type of the n-type channel semiconductor portion 5.
- the p-type dopant concentration of the semiconductor portion 6 is higher than the n- type dopant concentration of the channel semiconductor portion 5.
- the p + semiconductor 6 Punts are attached ;!] formed by mouthed SiC.
- the p + type embedded semiconductor section 4 is electrically connected to the electrode 6a via the p + type semiconductor section 6. It is also possible to use the electrode 6a as a good electrode, and the channel semiconductor portion between the p + type gate semiconductor portion 81 and the p + type buried semiconductor portion 4 has no connection semiconductor portion 11 However, the current path is large and the on-resistance can be reduced.
- the p + type buried semiconductor portion 4 is connected to the source electrode 7a by connecting the p + type semiconductor portion 6 to the source electrode 7a instead of the electrode 6a.
- the structure may be such that the source semiconductor unit 7 is electrically connected to the same source electrode 7a.
- the p + type buried semiconductor section 4 has the same potential as the source semiconductor section 7 and the capacitance between the P + type buried semiconductor section and the drain semiconductor section changes from the gate-drain capacity to the gate-source capacity. High frequency operation becomes possible.
- FIGS. 20A and 20B a tenth embodiment which is a modification of the eighth embodiment will be described with reference to FIGS. 20A and 20B.
- the same components as those in the method of manufacturing the vertical JFET 1f described in the eighth embodiment are denoted by the same reference numerals.
- a p + type semiconductor portion forming step different from that of the eighth embodiment will be described.
- Step of forming second p + type semiconductor layer A step of forming the p + type semiconductor layer will be described with reference to FIG.
- the second p + type semiconductor layer forming step is performed subsequent to the p + type semiconductor layer forming step.
- a mask Ml 2 having a pattern of a predetermined shape is formed.
- the dopant A 8 is selectively ion-implanted into the region 51 c defined on the SiC film 51 to form the p + type semiconductor layer 61.
- the depth of the ion implantation is deep enough to reach the p + type buried semiconductor portion 4.
- the dopant concentration of the p + -type semiconductor layer 61 is similar to that of the p + -type buried semiconductor portion 4.
- P + -Type Connection Semiconductor Layer Forming Step Referring to FIG. 20B, p + -type connection The step of forming a semiconductor layer will be described. Prior to the formation of the P + type connection semiconductor layer, an n-type semiconductor film 52, a p + type semiconductor portion 82, and a p + type semiconductor portion 62 are formed. A mask Ml3 having a pattern of a predetermined shape is formed. The dopant A 9 is selectively ion-implanted into the region 52 a formed on the n-type semiconductor film 52 by the mask Ml 3 to form the p + -type connection semiconductor portion layer 11. The depth of the ion implantation is deep enough to reach the p + type gate semiconductor portion 81. The dopant concentration of the p + -type connection semiconductor layer 111 is almost the same as that of the p + -type semiconductor layer 61. After the formation of the p + type connection semiconductor layer 111, the mask Ml3 is removed.
- a channel semiconductor film forming step is performed.
- a stacked channel portion is formed on the n-type drift semiconductor portion 3 by repeating the channel semiconductor film forming process, the P + type semiconductor layer forming process, the second p + type semiconductor layer forming process, and the p + type connecting semiconductor layer forming process. I do.
- the steps after the second p + type semiconductor layer forming step different from the eighth embodiment have been described. Other steps are the same as those in the eighth embodiment, but are not limited thereto.
- a first embodiment which is a modification of the first embodiment, will be described with reference to Figs. 21A and 21B.
- the same components as those in the configuration of the vertical JFET 1a described in the first embodiment are denoted by the same reference numerals.
- differences from the first embodiment will be described.
- FIG. 21A is a perspective view of the vertical JFET 1h in the first embodiment.
- the eleventh embodiment differs from the first embodiment in the structure of the channel semiconductor unit. That is, in the first embodiment, the channel semiconductor section has a pulse-doped structure.
- the pulse-doped semiconductor section 12 includes n ⁇ type SiC layers 121 to 124 and n + type SiC layers 125 to 127 arranged alternately. It is configured.
- the n-type dopant concentration of the SiC layers 121 to 124 is Si. layer Lower than the n-type dopant concentration of 125-127.
- the dopant concentration of the n-type SiC layers 12 1 to 12 4 is, for example, about 1 ⁇ 10 16 Zc; m 3 .
- the thickness T6 of the n-type SiC layers 121 to 124 is, for example, about 10 nm. !
- the salt concentration is 1 ⁇ 10 17 Z cm 3 to 1 ⁇ 10 18 Z cm 3 .
- the thickness T7 of the n + type SiC layers 125 to 127 is, for example, about 10 nm.
- the pulse-doped structure can be applied to the vertical JFET 1 # channel semiconductor section described in the seventh embodiment.
- the pulse-doped structure can also be applied to the vertical J F ⁇ 1 g channel semiconductor portion described in the ninth embodiment, as shown in FIG.
- the p + type embedded semiconductor section 4 is connected to the source electrode 7a by connecting the p + type semiconductor section 6 instead of the electrode 6a.
- the source semiconductor section 7 may be electrically connected to the same source electrode 7a.
- the p + type buried semiconductor portion 4 has the same potential as the source semiconductor portion 7, and the capacitance formed in the P + type buried semiconductor portion and the drain semiconductor portion changes from the gate-to-drain capacitance to the source-to-drain capacitance. Therefore, high-frequency operation becomes possible.
- Embodiment 12 which is a modified embodiment of Embodiment 1 will be described.
- the same components as those in the configuration of the vertical JFET 1a described in the first embodiment are denoted by the same reference numerals.
- differences from the first embodiment will be described.
- FIG. 23 is a perspective view of a vertical JFET 1n according to the first and second embodiments.
- the first and second embodiments are different from each other in the structure of the gate semiconductor unit.
- the vertical J FET ln has the P + type semiconductor section 13 in the gate semiconductor section 4.
- the p + type semiconductor section 13 is formed between the buried semiconductor section 4 and the channel semiconductor section 5 and the p + type semiconductor section 6.
- the p + type semiconductor portion 13 is formed of SiC to which A 1 (aluminum) is added as a dopant.
- the gate semiconductor part 4 is formed of SiC to which B (boron) is added as a dopant.
- the gate semiconductor section 4 is formed between the p + type semiconductor section 13 and the drift semiconductor section 3.
- the dopant concentration of the gate semiconductor portion 4 is lower than the dopant concentration of the p + type semiconductor portion 13.
- the depletion layer also extends to the gate semiconductor portion 4, so that the potential gradient between the gate semiconductor portion and the drift semiconductor portion can be moderated, and the concentration of the electric field is reduced. As a result, the withstand voltage of the vertical JFET is improved.
- the present structure is also applicable to the gate semiconductor portion of the vertical J FET 1f described in the seventh embodiment. Further, as shown in FIG. 24B, the pulse-doped structure can be applied to the vertical J FET 1 g gate semiconductor unit described in the ninth embodiment.
- the dopant concentration of the gate semiconductor portion 4 can be made lower than the dopant concentration of the p + type semiconductor portion 13.
- the depletion layer also extends to the gate semiconductor portion 4, so that the potential gradient between the gate semiconductor portion and the drift semiconductor portion can be moderated, and the concentration of the electric field is reduced.
- the pressure resistance of the vertical JFET is improved.
- the p + type embedded semiconductor section 6 is connected to the source electrode 7 a instead of the electrode 6 a to connect the p + type embedded semiconductor section 6. 4 and the source semiconductor section 7 may be electrically connected to the same source electrode 7a.
- the p + type buried semiconductor section 4 has the same potential as the source semiconductor section 7, and the capacity formed between the P + type buried semiconductor section and the drain semiconductor section changes from the gate-drain capacitance to the source-drain High lap because it changes to the capacity between Wave operation becomes possible.
- FIG. 25 is a cross-sectional view of the vertical J FET 1r according to the thirteenth embodiment.
- the thirteenth embodiment differs from the first embodiment in the structure of the drift semiconductor unit. That is, in the first embodiment, the drift semiconductor portion has the same conductivity type as the conductivity type of the n + type drain semiconductor portion 2, but in the first embodiment, the drift semiconductor portion has a different conductivity type. It has a super junction (SJ) structure composed of semiconductor regions.
- SJ super junction
- the drift semiconductor portion is provided on the main surface of n + type drain semiconductor portion 2.
- the drift semiconductor portion has p-type semiconductor regions 31 and 33 and an n-type semiconductor region 32 extending along a reference plane intersecting the main surface of the n + type drain semiconductor portion 2.
- the p-type semiconductor regions 31 and 33 are arranged so as to sandwich the n-type semiconductor region 32.
- the junction between the p-type semiconductor region and the n-type semiconductor region is located between the p + -type gate semiconductor portions 41, 42 and the n + -type drain semiconductor portion 2.
- the p-type semiconductor regions 31 and 33 are located between the p + -type gate semiconductor portions 41 and 42 and the n + -type drain semiconductor portion 2 and the p + -type gate semiconductor portions 41 and 4 2 (in the X-axis direction in the figure).
- the n-type semiconductor region 32 is formed of an n-type channel semiconductor portion 5 between the p + -type gate semiconductor portion 41 and the p + -type gate semiconductor portion 42 and an n + -type drain semiconductor portion 2. It is located between them and extends along the p + -type gate semiconductor portions 41 and 42 (in the X-axis direction in the figure).
- the n-type semiconductor region 32 has the same conductivity type as the conductivity type of the drain semiconductor portion 2.
- FIG. 26 is a cross-sectional view of a vertical JFET 1 s showing another embodiment having a super junction structure. As shown in FIG. 26, the super-junction structure is also applicable to the drift semiconductor section of the vertical J FET 1 f described in the seventh embodiment.
- Figure 2 is a cross-sectional view of a vertical JFET 1 s showing another embodiment having a super junction structure. As shown in FIG. 26, the super-junction structure is also applicable to the drift semiconductor section of the vertical J FET 1 f described in the seventh embodiment.
- FIG. 7 is a cross-sectional view of a vertical JFET 1t showing still another form having a super junction structure.
- the super-junction structure is also applicable to the vertical J FET 1 g drift semiconductor section described in the ninth embodiment.
- the super junction structure can be applied to the vertical J FET described in the other embodiments.
- the drift semiconductor portion is configured by a plurality of semiconductor regions having different conductivity types.
- the drift semiconductor section having such a structure when the drain voltage is high, the entire drift semiconductor section is sufficiently depleted. Therefore, the maximum value of the electric field in the drift semiconductor portion is reduced. Therefore, the thickness of the drift semiconductor portion can be reduced. For this reason, the on-resistance is reduced.
- the dopant concentrations of the p-type semiconductor regions 31 and 33 and the n-type semiconductor region 32 be substantially the same.
- the dopant concentration of the p-type semiconductor regions 31 and 33 and the n-type semiconductor region 32 is about 2.7 ⁇ 10 17 cm 3 .
- the width of the p-type semiconductor regions 31 and 33 and the n-type semiconductor region 32 is about 0.5 m.
- FIG. 28A is a schematic diagram illustrating a positional relationship between each semiconductor region and a gate semiconductor unit in the fourteenth embodiment.
- P-type semiconductor regions 31, 33 and n-type semiconductor regions Both 32 extend in a predetermined axial direction (X-axis direction in the figure).
- the P-type semiconductor regions 31 and 33 are arranged so as to sandwich the n-type semiconductor region 32.
- the junction between the p-type semiconductor region and the n-type semiconductor region is located below the p + -type gate semiconductor portions 41 and 42.
- FIG. 28B is a schematic diagram illustrating a positional relationship between each semiconductor region and the gate semiconductor unit in the fourteenth embodiment.
- Both the p-type semiconductor regions 31 and 33 and the n-type semiconductor regions 32 and 34 extend in a predetermined axial direction (x-axis direction in the figure).
- the p-type semiconductor regions 31 and 33 are alternately arranged with the n-type semiconductor regions 32 and 34.
- the junction between the p-type semiconductor region and the n-type semiconductor region is located not only below the P + type gate semiconductor portions 41 and 42 but also between the respective gate semiconductor portions.
- FIG. 28C is a schematic diagram showing a positional relationship between each semiconductor region and the good semiconductor portion in still another mode.
- the p-type semiconductor regions 31 and 33 and the n-type semiconductor region 32 all extend in a predetermined axial direction (y-axis direction in the figure).
- the p-type semiconductor regions 31 and 33 are arranged so as to sandwich the n-type semiconductor region 32. There may be a plurality of n-type semiconductor regions.
- an n + -type SiC semiconductor substrate is prepared.
- the n-type impurity concentration of the substrate is so high that the substrate can be used as a drain semiconductor portion.
- a SiC film 3 is formed on the surface of the n + type drain semiconductor portion 2 by an epitaxy growth method.
- the thickness 8 of the 31 film 3 is not less than 2.0 / im and not more than 3.0 ⁇ m.
- the conductivity type of the SiC film 3 is the same as the conductivity type of the drain semiconductor unit 2. Further, the dopant concentration of the SiC film 3 is lower than the dopant concentration of the n + type drain semiconductor portion 2.
- n-type semiconductor layers 32, 34 and 36 are formed.
- P-type semiconductor layer forming step A step of forming a p-type semiconductor layer will be described with reference to FIG. Using a predetermined mask M, the dopant A 10 is selectively ion-implanted into the regions 31 a, 33 a, 35 a, and 37 a formed on the n-type semiconductor layer 3 so that the predetermined depth is obtained. P-type semiconductor layers 31 1, 33 1, 35 1, and 37 1 are formed. After forming the p-type semiconductor layer, the mask M is removed.
- drift semiconductor part forming step A step of forming a drift semiconductor part having a desired thickness will be described with reference to Fig. 29C. That is, the n-type semiconductor layer forming step and the p-type semiconductor layer forming step are alternately repeated to form a drift semiconductor part having a super junction structure on the n + -type drain semiconductor part 2. As a result, a semiconductor layer 3 having a predetermined thickness (the Z- axis direction in the figure) is formed.
- the method for forming the drift semiconductor portion having the n-type semiconductor region and the p-type semiconductor region has been described above. Other steps are the same as those in the second, sixth, and eighth embodiments, but are not limited thereto.
- FIG. 30 is a sectional view of a vertical JFET 1 u according to a sixteenth embodiment.
- the vertical J FET lu is composed of an n + type drain semiconductor section 2, an n-type drift semiconductor section 3, a p-type buried semiconductor section 4, an n-type channel semiconductor section 5, and a p + It has a type gate semiconductor section 6 and an n + type source semiconductor section 7.
- the vertical J FET lu has a vertical structure in which majority carriers move in a direction from one surface of the device to the other surface (hereinafter, referred to as "current direction").
- Figure 30 shows the coordinate system. These coordinates are defined so that the current direction of the JFET channel section is aligned with the y-axis.
- the n + type drain semiconductor portion 2 has a pair of opposing surfaces. Further, the n + -type drain semiconductor portion 2 can be a substrate to which a dopant is added. In a preferred embodiment, the substrate is formed of SiC (silicon carbide). Dopants added to SiC include N (nitrogen), P, which is a group 5 element of the periodic table. Donor impurities such as (phosphorus) and As (arsenic) can be used.
- the n + type drain semiconductor portion 2 has a drain electrode 2a on one (back surface) of a pair of surfaces. The drain electrode 2a is formed of a metal.
- the n-type drift semiconductor unit 3 is provided on the other (front surface) of the pair of surfaces of the n + -type drain semiconductor unit 2.
- the n-type drift semiconductor unit 3 has first to fourth regions 3a, 3b , 3c , 3d arranged on the surface thereof in the y- axis direction in order.
- the first to fourth regions 3a, 3b, 3c, 3d extend in a predetermined axial direction (x-axis direction in FIG. 30), and are rectangular regions in a preferred embodiment. .
- a p-type embedded semiconductor section 4 is provided on the first, second, and fourth regions 3a, 3b, and 3d.
- the channel semiconductor section 5 is provided on the first to third regions 3a, 3b, 3c.
- the conductivity type of the drift semiconductor portion 3 is the same as the conductivity type of the drain semiconductor portion 2, and the dopant concentration of the drift semiconductor portion 3 is lower than the dopant concentration of the drain semiconductor portion 2.
- the drift semiconductor portion 3 is formed of SiC (silicon carbide) to which a dopant is added.
- the p-type embedded semiconductor unit 4 is provided on the first to third regions 3a, 3b, 3c.
- the conductivity type of the buried semiconductor portion 4 is opposite to the conductivity type of the drift semiconductor portion 3.
- the p-type buried semiconductor portion 4 is formed of SiC (silicon carbide) to which a dopant is added.
- acceptor impurities such as B (boron) and A 1 (aluminum), which are Group 3 elements of the periodic table, can be used.
- the n-type channel semiconductor section 5 is provided on the first to third regions 3a, 3b, 3c.
- the n-type channel semiconductor section 5 extends along the p-type buried semiconductor section 4 in a predetermined axial direction (y-axis direction in FIG. 30).
- the n-type channel semiconductor section 5 is electrically connected to the n-type drift semiconductor section 3 in the third region 3c. Since the conductivity type of the channel semiconductor portion 5 is opposite to the conductivity type of the embedded semiconductor portion 4, a pn junction is formed at the interface between the embedded semiconductor portion 4 and the channel semiconductor portion 5.
- n- type channel half The drain current flowing through the conductor 5 is controlled by the p-type buried semiconductor 4.
- the dopant concentration of the n-type channel semiconductor section 5 is lower than the dopant concentration of the n + -type drain semiconductor section 2.
- the n- type channel semiconductor section 5 is formed of SiC to which a dopant is added.
- the channel length (y-axis in the figure) is greater than 10 times the channel thickness (z-axis in the figure).
- the p + -type gut semiconductor section 6 is provided on the fourth region 3d and the p-type buried semiconductor section 4.
- the p + type gate semiconductor section 6 extends in the vertical direction (the X-axis direction in FIG. 30).
- a gate electrode 6a is provided on the surface of the p + type gate semiconductor section 6.
- Gate electrode 6a is formed of metal.
- the p + -type gate semiconductor section 6 connects the p-type buried semiconductor section 4 to the gate electrode 6a.
- the n + -type source semiconductor unit 7 is provided on the first region 3a and the n-type channel semiconductor unit 5.
- the source semiconductor portion 7 has the same conductivity type as the conductivity type of the drain semiconductor portion 2.
- the source semiconductor section 7 is connected to the drift semiconductor section 3 via the channel semiconductor section 5.
- a source electrode 7 a is provided on the n + -type source semiconductor unit 7.
- Source electrode 7a is formed of metal.
- the n-type channel semiconductor section 5 is insulated from the source electrode 7a by insulating films 8 and 9 such as silicon oxide films.
- FIGS. 31A to 31C, 32A to 32C, 33A to 33C, 34A to 34C, and 35 show the vertical J FET 1 u according to the 17th embodiment. It is sectional drawing which shows the manufacturing process.
- a substrate is prepared as shown in FIG. 31A.
- an n + type SiC semiconductor substrate is exemplified.
- the dopant concentration of the substrate is so high that the substrate can be used as the drain semiconductor portion 2.
- a SiC film 3 is formed on the surface of the n + type drain semiconductor portion 2 by an epitaxy growth method. S i
- the film thickness T 1 of the C film 3 is, for example, 10 m.
- the conductivity type of the SiC film 3 is the same as the conductivity type of the n + -type drain semiconductor unit 2.
- the dopant concentration of the SiC film 3 is lower than the dopant concentration of the n + -type drain semiconductor portion 2.
- the dopant concentration of S i Cfl 3 is, for example, about 1 ⁇ 10 16 / cm 3 . From the S i C film 3, an n-type drift semiconductor portion is formed.
- a step of forming an embedded semiconductor section will be described with reference to FIG. 31C.
- a mask Ml having a pattern extending in a predetermined axial direction (X-axis direction in the figure) is formed.
- a dopant A1 is selectively ion-implanted into a region 3e formed on the SiC film 3 to form a p-type buried semiconductor portion 4 having a predetermined depth.
- the depth D 1 of the p-type buried semiconductor section 4 is, for example, about 1.2 m.
- the dopant concentration of the p-type buried semiconductor portion 4 is, for example, IX It is about.
- a SiC film 5 is formed on the surface of the p-type buried semiconductor portion 4 and the SiC film 3 by an epitaxy method. .
- the thickness T 2 of the SiC film 5 is, for example, about 0.3 ⁇ .
- the conductivity type of S i Cfl 5 is the same as the conductivity type of n + type drain semiconductor unit 2.
- the dopant concentration of the SiC film 5 is lower than the dopant concentration of the n + type drain semiconductor portion 2.
- the dopant concentration of the SiC film 5 is, for example, about 1 ⁇ 10 17 cm 3 .
- an n-type channel semiconductor portion is formed.
- the S i C film is formed for each of the drift semiconductor portion and the channel semiconductor portion.
- a plurality of film forming steps for repeatedly forming a film may be included.
- a desired dopant concentration profile can be adopted for the SiC film so that the SiC film 3 functions as a drift semiconductor part and a channel semiconductor part.
- an S i C film 7 for an n + type source layer is formed on the surface of the S i C film 5 by an epitaxial growth method. I do.
- the thickness T 3 of the SiC film 7 is, for example, about 0.2 ⁇ m.
- the conductivity type of the SiC film 7 is the same as the conductivity type of the n + type drain semiconductor unit 2. Further, the dopant concentration of the SiC film 7 is higher than the dopant concentration of the SiC film 5.
- a mask M2 having a pattern extending in a predetermined axial direction (X-axis direction in the figure) is formed.
- Step of Forming Source and Channel Semiconductor Part A step of forming the source semiconductor part will be described with reference to FIG. 32C.
- the n + type source layer 7 and the SiC film 5 and the SiC film 3 are selectively etched until the depth reaches D2.
- the portion of the n + type source layer 7 and the S i C film 5 covered with the mask M2 remains without being etched, and becomes an n + type source semiconductor portion.
- the thickness T4 of the SiC film 3 on the surface of the P-type buried semiconductor portion that is not covered with the mask greatly affects the characteristics of JFET (intrinsic channel semiconductor portion).
- the etching depth D 2 is, for example, about 0.4 / im, and the thickness T 4 of the etched SiC film 3 is, for example, about 0.1 ⁇ .
- the mask # 2 is removed.
- a mask # 3 having a pattern extending in a predetermined axial direction (X-axis direction in the figure) is formed.
- [0176] (Step of Forming ⁇ + Semiconductor Portion) A step of forming a ⁇ + type gate semiconductor portion will be described with reference to FIG. 32C. Using the mask # 3, the dopant A2 is selectively ion-implanted into the region 5a formed on the SiC film 5 to form the p + type gate semiconductor portion 6. Referring to FIG. 33A, a p + -type gate semiconductor portion 6 reaching the p-type buried semiconductor portion 4 is formed in the semiconductor portion 5. After forming the p + type semiconductor portion, the mask M3 is removed.
- Thermal Oxidation Step A step of thermally oxidizing the vertical JFET 1u will be described with reference to FIG. 33B. Thermal oxidation is applied to the vertical J FET 1 u. Thermal oxidation treatment, the exposure of the S i C in an oxidizing atmosphere at high temperatures (e.g., about 1 200 ° C), silicon and oxygen chemically reacts silicon oxide film in the semiconductor unit (S i 0 2) is formed Is done. As a result, the surface of each semiconductor portion is covered with the oxide film 8.
- high temperatures e.g., about 1 200 ° C
- FIG. 33C a process for forming a gate electrode was performed.
- the step of forming the opening will be described.
- the oxide film 8 is selectively etched using a photoresist mask to form an opening.
- the surface portions of the p + -type good semiconductor portion 6 and the n + -type source semiconductor portion 7 are exposed.
- the exposed portions serve as conductive portions to the gate electrode and the source electrode, respectively.
- the resist mask is removed.
- Electrode formation step The step of forming an electrode will be described with reference to Fig. 34A.
- a metal film for an electrode such as Ni is deposited.
- a photoresist mask having a predetermined shape is formed.
- the metal film for the electrode is selectively etched.
- the portion of the electrode metal film covered with the resist pattern remains without being etched, and becomes the gate electrode 6a and the source ohmic electrode 7a.
- the resist mask is removed.
- an insulating film 9 such as Si ⁇ 2 and Si ON is formed by CVD (Chemical Vapor Deposition) or the like.
- a step of forming an opening for forming a source electrode will be described with reference to FIG. 34C.
- oxide film 8 and insulating film 9 are selectively etched to form contact holes 9a.
- the surface portion of the source ohmic electrode 7a is exposed.
- the exposed portion becomes a conductive portion to the source electrode.
- the contact hole 9a is provided so as to reach the source ohmic electrode 7a. After forming the contact holes 9a, the resist mask is removed.
- Source electrode 7b is formed so as to be in contact with the surface of source semiconductor unit 7.
- Source electrode 7b is in contact with source semiconductor section 7 through contact hole 9a shown in FIG. 34C.
- Aluminum (A 1) and A 1 alloy are preferable as the material of the wiring metal film from the viewpoint of low resistance, ease of fine processing and adhesion, but copper (Cu) and tungsten (W) are preferred.
- the present invention is not limited to these.
- the vertical JFET lu shown in the sixteenth embodiment was completed.
- the p-type buried semiconductor section 4 and the n-type channel semiconductor section 5 can be arranged on the n-type drift semiconductor section 3. Therefore, a desired drain withstand voltage can be obtained by increasing the thickness of the n-type drift semiconductor section 3 without increasing the chip size. Therefore, the breakdown voltage between the source and the drain can be improved.
- carriers flow not only below the n-type channel semiconductor section 5 but also to the n-type drift semiconductor section 3 located below the p-type buried semiconductor section 4. Therefore, the on-resistance can be reduced while maintaining the withstand voltage. In other words, this structure is suitable for a high breakdown voltage JFET.
- the drain, source, and gate semiconductor portions are formed of SiC.
- S i C has the following advantages over semiconductors such as S i (silicon) and G aAs (gallium arsenide).
- the device has a high melting point and a large band gap (forbidden band width), which facilitates high-temperature operation of the device.
- the insulation breakdown electric field is large, high breakdown voltage and low loss can be achieved.
- heat radiation is facilitated because of high thermal conductivity.
- FIG. 36 is a cross-sectional view of the vertical JFET 1V according to the eighteenth embodiment.
- the eighteenth embodiment and the sixteenth embodiment differ in the structure of the channel region. That is, in the sixteenth embodiment, the configuration is such that the n-type channel semiconductor section 5 contacts the n + -type source semiconductor section 7 on the first region 3a.
- the vertical J FET 1 v further includes an n ⁇ type semiconductor section 10 between the n type channel semiconductor section 5 and the n + type source semiconductor section 7. . According to this structure, since the n-type channel semiconductor portion 5 is not etched, the thickness of the channel semiconductor portion is not affected by the variation due to the etching process. Therefore, individual differences in the electrical characteristics of the vertical J FET lv can be reduced.
- the n-type semiconductor unit 10 is provided on the first to third regions 3a, 3b, 3c and the n-type channel semiconductor unit 5.
- the conductivity type of the semiconductor section 10 is the same as the conductivity type of the channel semiconductor section 5.
- the dopant concentration of the n_ type semiconductor section 10 is lower than the dopant concentration of the n-type channel semiconductor section 5.
- the dopant concentration of the n_ type semiconductor unit 10 is, for example, about 1 ⁇ 10 / Zcm 3 .
- the n-type semiconductor portion 10 is made of SiC (silicon carbide) to which a dopant is added.
- the channel structure including the n-type semiconductor portion and the n-type semiconductor portion described in the present embodiment is applicable to not only the sixteenth embodiment but also all the embodiments described below (twentieth embodiment). To the twenty-eighth embodiment).
- FIGS. 37A to 37C a ninth embodiment which is a modification of the 17th embodiment will be described with reference to FIGS. 37A to 37C.
- the manufacturing method of the vertical JFET in the nineteenth embodiment is described in the seventeenth embodiment.
- the same components as those in the method of manufacturing the vertical JFET 1u are denoted by the same reference numerals.
- a step of forming a channel semiconductor film, a step of forming an n-type semiconductor film, and a step of forming a source semiconductor portion different from the seventeenth embodiment will be described.
- the channel semiconductor film forming step is performed subsequent to the good semiconductor part forming step.
- a SiC film 5 is formed on the surface of the p + type gate semiconductor portion 4 and the SiC film 3 by an epitaxy method.
- the thickness T 6 of the SiC film 5 is, for example, about 0.1 ⁇ .
- the conductivity type of the SiC film 5 is the same as the conductivity type of the n + type drain semiconductor unit 2.
- the dopant concentration of the SiC film 5 is lower than the dopant concentration of the n + -type drain semiconductor portion 2.
- the dopant concentration of the SiC film 5 is, for example, about 1 ⁇ 10 17 / cm 3 . From the SiC film 5, an n-type channel semiconductor portion is formed.
- an S i C film 10 is formed on the surface of the S i C film 5 by an epitaxy growth method.
- the thickness T 7 of S i Cfl 10 is, for example, about 0.
- the conductivity type of the S i C film 10 is the same as the conductivity type of the S i C film 5.
- the dopant concentration of the SiC film 10 is lower than the dopant concentration of the SiC film 5.
- the dopant concentration of the SiC film 10 is, for example, about 1 ⁇ 10 16 Z cm 3 . From this S i C film 10, an n-type semiconductor portion is formed.
- Step of Forming Source Semiconductor Film Subsequently, a step of forming a source semiconductor film will be described with reference to FIG. 37B.
- An S i C film 7 for an n + type source layer is formed on the surface of the S i C film 10 by an epitaxial growth method.
- the thickness of the SiC film 7 is, for example, about 0.
- the conductivity type of the SiC film 7 is the same as the conductivity type of the n + -type drain semiconductor unit 2.
- the dopant concentration of S i C film 7 is higher than the dopant concentration of S i C film 10, for example, about l X l O / cm 3.
- Step of forming source semiconductor portion A step of forming the source semiconductor portion will be described with reference to Fig. 37C.
- Mask M having a pattern covering a predetermined area Form 4.
- the n + type source layer 7 and the n ⁇ type semiconductor layer 10 are selectively etched using the mask M4.
- the etching depth D 3 is a depth that does not reach the semiconductor layer 5.
- the channel semiconductor film forming step, the n- type semiconductor film forming step, and the source semiconductor part forming step different from the seventeenth embodiment have been described above. Subsequent to the source semiconductor part forming step, a P + type semiconductor part forming step is performed. Other steps are the same as in the seventeenth embodiment. According to the method of manufacturing the vertical JFET in this embodiment, the SiC film 5 is not etched in the source semiconductor portion forming step. Therefore, the thickness of the channel semiconductor portion is not affected by the variation due to the etching process. Therefore, individual differences in electrical characteristics of transistors can be reduced.
- FIG. 38 is a perspective view of the vertical J FET 1 w.
- the vertical J FET lw has an n + type drain semiconductor section 2, an n type drift semiconductor section 3, a p + type gate diffusion semiconductor section 41, 42, 43, 44, 45, It has an n-type channel semiconductor section 5 and an n + -type source semiconductor section 7 having a batch source electrode 7a on its surface.
- the p + type gate diffusion semiconductor sections 41 to 45 control the role of gate wiring for external connection provided on the outer periphery of the basic cell of the transistor / semiconductor chip and control of the channel width. It also has a function as a gate. That is, the p + -type gate diffusion semiconductor portions 41 to 45 are formed so as to be embedded in the n-type channel semiconductor portion 5 at predetermined intervals in the y-axis direction. Each of the p + type gut diffusion semiconductor portions 41 to 45 extends in a predetermined axial direction (the X-axis direction in FIG. 38). In a preferred embodiment, the p + -type gate diffusion semiconductor portions 41 to 45 are doped with a dopant. It is formed of SiC (silicon carbide). The gate electrode 4a is provided so as to surround a collective source electrode 7a described later.
- the n + -type source semiconductor unit 7 is provided on the n-type channel semiconductor unit 5.
- the source semiconductor section 7 has the same conductivity type as the conductivity type of the drain semiconductor section 2.
- the n + -type source semiconductor unit 7 is connected to the n-type drift semiconductor unit 3 via the n-type channel semiconductor unit 5.
- a batch source electrode 7 a is provided on the surface of the n + type source semiconductor section 7.
- Collective source electrode 7a is formed of metal. Further, the p + -type gate diffusion semiconductor section 41 and the n + -type source semiconductor section 7 are electrically connected by the collective source electrode 7a.
- Fig. 39 is a cross-sectional view of the vertical JFET 1x in the twenty-first embodiment.
- the structure of the gate semiconductor unit is different between the twenty-first embodiment and the sixteenth embodiment. That is, in the twenty-first embodiment, the p + -type gut semiconductor portion 11 is provided on the second and third regions 3 b and 3 c and the n-type channel semiconductor portion 5.
- the conductivity type of the gate semiconductor portion 11 is opposite to the conductivity type of the channel semiconductor portion 5. Since the p-type dopant concentration of the gate semiconductor portion 11 is higher than the n-type dopant concentration of the channel semiconductor portion 5, the depletion layer extends to the channel semiconductor portion. p
- the dopant concentration of the + -type gate semiconductor portion 11 is, for example, about 1 ⁇ 10 18 Z C m 3 . is there.
- the P-type gate semiconductor portion 11 is formed of SiC to which a dopant has been added.
- the thickness of the p-type gate semiconductor portion is, for example, about 0.3 / im. Since the vertical J FET lx has the n-type channel semiconductor section 5 between the p-type buried semiconductor section 4 and the p-type gate semiconductor section 11, the channel can be controlled from both sides of the n-type channel semiconductor section 5. According to this structure, the width of the controllable channel is increased as compared with the case where the channel is controlled from one side of the n-type channel semiconductor unit 5. As a result, a structure in which normally-off is easily realized is provided.
- FIGS. 40A and 40B Regarding the method of manufacturing the vertical JFET in the second embodiment, the same components as those in the method of manufacturing the vertical JFET 1u described in the seventeenth embodiment are denoted by the same reference numerals. .
- a description will be given of a p + -type gate semiconductor portion forming step different from that of the seventeenth embodiment.
- the p + -type gate semiconductor part forming step is performed subsequent to the p + -type semiconductor part forming step.
- a process of forming a p + type good semiconductor portion will be described.
- a dopant A2 is selectively ion-implanted into a region 5a on the SiC film 5 to form a P + type gate semiconductor portion 11 having a predetermined depth. I do.
- the thickness D4 of the channel layer formed by forming the P + type gate semiconductor portion 11 is determined according to the threshold value of the vertical JFET. For example, D4 is about 0.2 // in.
- the mask M3 is removed.
- the result is a vertical JFET as shown in Figure 40B.
- the p + type gate semiconductor portion forming process different from the seventeenth embodiment has been described above.
- a thermal oxidation step is performed.
- the other steps are the same as those in the seventeenth embodiment, but are not limited thereto.
- FIG. 41 is a cross-sectional view of the vertical JFET 1y according to the twenty-third embodiment.
- the 23rd embodiment differs from the 16th embodiment in the structure of the gate semiconductor portion. That is, in the twenty-third embodiment, the vertical J FET ly includes the p + -type gate semiconductor portion 12.
- the pn junction between the n-type channel semiconductor section 5 and the p + -type gate semiconductor section 12 is a hetero junction.
- the n-type channel semiconductor section 5 is formed of SiC.
- the p + type gate semiconductor section 12 is formed of polysilicon. This eliminates the need for the SiC epitaxy growth step for forming the p + -type gate semiconductor portion 11 shown in the second embodiment, and allows the vertical JFET 1y to be easily configured.
- FIG. 42A is a cross-sectional view of a vertical JFET 1z according to the twenty-fourth embodiment.
- the twenty-fourth embodiment differs from the sixteenth embodiment in the structure of the gate semiconductor unit. That is, in the twenty-fourth embodiment, the p + -type gate semiconductor unit 4 and the p + -type good semiconductor unit 11 sandwich the channel region.
- the vertical J FET lz further includes a p + -type semiconductor section 13 provided in the channel region of the n-type channel semiconductor section 5.
- the P + type semiconductor section 13 is provided on the region 4 a of the p + type gate semiconductor section 4.
- the p + type semiconductor portion 13 is provided so as to partially penetrate the n type channel semiconductor portion 5. [0209] FIG.
- the p + type semiconductor sections 13 are arranged in the n-type channel semiconductor section 5 at predetermined intervals in the X-axis direction.
- the dopant concentration of the p + -type semiconductor portion 13 is higher than the dopant concentration of the n-type channel semiconductor portion 5. For this reason, the depletion layer mainly extends into the n-type channel semiconductor section 5.
- the p + type semiconductor portion 13 is formed of SiC to which a dopant is added.
- the p + -type gate semiconductor unit 4 is electrically connected to the p + -type gate semiconductor unit 11 via the p + -type semiconductor unit 13. Thereby, the same potential is applied to the p + -type gate semiconductor portion 4 and the p + -type gate semiconductor portion 11, so that the thickness of the channel layer can be increased.
- FIG. 43A is a cross-sectional view of a vertical J FET 10a according to the twenty-fifth embodiment.
- the twenty-fifth embodiment differs from the sixteenth embodiment in the structure of the channel semiconductor unit. That is, in the twenty-fifth embodiment, the channel semiconductor unit has a pulse dope structure.
- the pulse-doped semiconductor section 14 is configured by alternately stacking n- type SiC layers 141 to 144 and n + type SiC layers 145 to 147. Further, the dopant concentration of the n ⁇ type S 1 ⁇ layers 141 to 144 is lower than the dopant concentration of the n + type S 1 ⁇ layers 145 to 147.
- the dopant concentration of the n-type SiC layers 141 to 144 is, for example, about 1 ⁇ 10 16 cm 3 .
- the thickness T8 of the n-type SiC layers 141 to 144 is, for example, about 10 nm. !
- the dopant concentration of the 1+ type 3 1 layer 145 to 147 is 1 ⁇ 10 17 cm 3 to 1 ⁇ 10 18 Z cm 3 It is.
- the thickness T9 of the n + type SiC layer 145 to 147 is, for example, about 10 nm.
- Fig. 44 is a cross-sectional view of the vertical J FET 10b in the twenty-sixth embodiment.
- the 26th embodiment differs from the first embodiment in the structure of the drift semiconductor unit. That is, in the first embodiment, the drift semiconductor portion has the same conductivity type as the conductivity type of the n + type drain semiconductor portion 2. However, in the twenty-sixth embodiment, the drift semiconductor portion has the conductivity type. It has a super junction (SJ) structure composed of different semiconductor regions.
- SJ super junction
- the drift semiconductor portion is provided on the main surface of n + type drain semiconductor portion 2.
- the drift semiconductor portion has p-type semiconductor regions 31 and 33 and an n-type semiconductor region 32 extending along a reference plane intersecting the main surface of the n + type drain semiconductor portion 2.
- the p-type semiconductor regions 31 and 33 are arranged so as to sandwich the n-type semiconductor region 32.
- the junction surface between the p-type semiconductor region and the n-type semiconductor region is located between the p + -type gate semiconductor portions 41, 42 and the n + -type drain semiconductor portion 2.
- the p-type semiconductor regions 31 and 33 are located between the p + -type gate semiconductor portions 41 and 42 and the n + -type drain semiconductor portion 2 and the p + -type gate semiconductor portion 41 , 42 (in the X-axis direction in Fig. 44).
- the n-type semiconductor region 32 includes an n-type channel semiconductor portion 5 between the p + -type gate semiconductor portion 41 and the p + -type gate semiconductor portion 42, and an n + -type drain semiconductor portion 2. And extends in the direction along the P + type gate semiconductor portions 41 and 42 (the X-axis direction in FIG. 44).
- the n-type semiconductor region 32 has the same conductivity type as the conductivity type of the drain semiconductor portion 2.
- the super-junction structure can be applied to the drift semiconductor portion of the vertical J FET 1X described in the twenty first embodiment. Further, as shown in FIG. 46, the super-junction structure can be applied to the vertical J FET 1z drift semiconductor section described in the twenty-fourth embodiment. The super junction structure can also be applied to the vertical JFET described in other embodiments.
- the drift semiconductor portion is constituted by a plurality of semiconductor regions having different conductivity types.
- the entire drift semiconductor section is sufficiently depleted. Therefore, the maximum value of the electric field in the drift semiconductor portion is reduced. Therefore, the thickness of the drift semiconductor portion can be reduced. For this reason, the on-resistance decreases.
- the p-type semiconductor regions 31 and 33 and the n-type semiconductor region 32 have substantially the same dopant concentration.
- dopant preparative concentration of P-type semiconductor regions 3 1, 33 and n-type semiconductor region 32 is about 2. 7 X 10 17 cm_ 3.
- the widths of the p-type semiconductor regions 31 and 33 and the n-type semiconductor region 32 are about 0.5 ⁇ .
- the depletion layer extends over the entire p-type semiconductor region and extends over the entire n-type semiconductor region. As described above, since the depletion layer extends to both semiconductor regions, the concentration of the electric field in the drift semiconductor portion is reduced.
- FIG. 47A shows the semiconductor regions and the gate semiconductor portions in the twenty-seventh embodiment It is a schematic diagram which shows the positional relationship of.
- the p-type semiconductor regions 31 and 33 and the n-type semiconductor region 32 all extend in a predetermined axial direction (X-axis direction in the figure).
- the p-type semiconductor regions 31 and 33 are arranged so as to sandwich the n-type semiconductor region 32.
- the junction between the p-type semiconductor region and the n-type semiconductor region is located below the p + type gate semiconductor portions 41 and 42.
- FIG. 47B is a schematic diagram showing a positional relationship between each semiconductor region and the gate semiconductor portion in the 27th embodiment.
- Both the p-type semiconductor regions 31 and 33 and the n-type semiconductor regions 32 and 34 extend in a predetermined axial direction (x-axis direction in the figure).
- the p-type semiconductor regions 31 and 33 are alternately arranged with the n-type semiconductor regions 32 and 34.
- the junction between the p-type semiconductor region and the n-type semiconductor region is located not only below the p + -type gate semiconductor portions 41 and 42 but also between the respective gate semiconductor portions.
- FIG. 47C is a schematic plan view showing the positional relationship between each semiconductor region and the gate semiconductor portion in still another mode.
- the p-type semiconductor regions 31 and 33 and the n-type semiconductor region 32 both extend in a predetermined axial direction (y-axis direction in the figure).
- the p-type semiconductor regions 31 and 33 are arranged so as to sandwich the n-type semiconductor region 32. There may be a plurality of n-type semiconductor regions.
- an n + -type SiC semiconductor substrate is prepared.
- the n-type impurity concentration of the substrate is so high that the substrate can be used as a drain semiconductor portion.
- a SiC film 3 is formed on the surface of the n + type drain semiconductor portion 2 by an epitaxy growth method.
- the thickness T 10 of the SiC film 3 is not less than 2. O / im and not more than 3.0 / m.
- the conductivity type of the SiC film 3 is the same as the conductivity type of the drain semiconductor unit 2.
- the dopant concentration of the SiC film 3 is lower than the dopant concentration of the n + type drain semiconductor portion 2. From the SiC film 3, the n-type semiconductor layer 3 2, 34, 3 6 Is formed.
- Step of forming p-type semiconductor layer The step of forming the p-type semiconductor layer will be described with reference to Fig. 48B.
- the dopant A 3 is selectively ion-implanted into the regions 3 la, 31 c, 31 e, and 31 g formed on the n-type semiconductor layer 3, and The P-type semiconductor layers 311, 331, 351, and 371 having a depth of 311 are formed.
- the mask M is removed.
- Step of Forming Drift Semiconductor Part A step of forming a drift semiconductor part having a desired thickness will be described with reference to FIG. 48C. That is, the n-type semiconductor layer forming step and the p-type semiconductor layer forming step are alternately repeated to form a drift semiconductor section having a super junction structure on the n + type drain semiconductor section 2. As a result, a semiconductor layer 3 having a predetermined thickness (the z-axis direction in the figure) is formed.
- the method for forming the drift semiconductor portion having the n-type semiconductor region and the p-type semiconductor region has been described above. Other steps are the same as those in the 18th, 20th, and 22nd embodiments, but are not limited thereto.
- the vertical JFET and the method of manufacturing the same according to the present invention are not limited to the embodiments described in the above embodiments, and various modifications may be made according to other conditions and the like. It is possible to take.
- a channel region is formed by an n-type semiconductor containing a donor impurity
- the present invention is also applicable to a JFET having a channel region formed by a P-type semiconductor. However, in this case, the current direction and the polarity of the applied gut voltage are reversed.
- the present invention it is possible to provide a low-loss vertical junction field effect transistor while maintaining a high drain breakdown voltage, and a method of manufacturing the vertical junction field effect transistor.
Description
Claims
Priority Applications (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2002215804A JP4122880B2 (ja) | 2002-07-24 | 2002-07-24 | 縦型接合型電界効果トランジスタ |
US10/522,278 US7282760B2 (en) | 2002-07-24 | 2003-07-24 | Vertical junction field effect transistors, and methods of producing the vertical junction field effect transistors |
CNB038154064A CN100349270C (zh) | 2002-07-24 | 2003-07-24 | 纵向结型场效应晶体管及其制造方法 |
KR1020057000626A KR100678251B1 (ko) | 2002-07-24 | 2003-07-24 | 종형 접합형 전계효과 트랜지스터, 및 종형 접합형전계효과 트랜지스터의 제조방법 |
EP03765376A EP1542270A4 (en) | 2002-07-24 | 2003-07-24 | VERTICAL JUNCTION FIELD EFFECT TRANSISTOR (JFET) AND METHOD FOR MANUFACTURING THE SAME |
US11/770,414 US7750377B2 (en) | 2002-07-24 | 2007-06-28 | Vertical junction field effect transistors, and methods of producing the vertical junction field effect transistors |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2002-215804 | 2002-07-24 | ||
JP2002215804A JP4122880B2 (ja) | 2002-07-24 | 2002-07-24 | 縦型接合型電界効果トランジスタ |
JP2002235045A JP4045893B2 (ja) | 2002-08-12 | 2002-08-12 | 縦型接合型電界効果トランジスタ |
JP2002-235045 | 2002-08-12 |
Related Child Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10522278 A-371-Of-International | 2003-07-24 | ||
US11/770,414 Division US7750377B2 (en) | 2002-07-24 | 2007-06-28 | Vertical junction field effect transistors, and methods of producing the vertical junction field effect transistors |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2004010489A1 true WO2004010489A1 (ja) | 2004-01-29 |
Family
ID=30772252
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2003/009412 WO2004010489A1 (ja) | 2002-07-24 | 2003-07-24 | 縦型接合型電界効果トランジスタ、及び縦型接合型電界効果トランジスタの製造方法 |
Country Status (7)
Country | Link |
---|---|
US (2) | US7282760B2 (ja) |
EP (4) | EP2378546A3 (ja) |
JP (1) | JP4122880B2 (ja) |
KR (1) | KR100678251B1 (ja) |
CN (1) | CN100349270C (ja) |
TW (1) | TWI288480B (ja) |
WO (1) | WO2004010489A1 (ja) |
Families Citing this family (49)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7642566B2 (en) * | 2006-06-12 | 2010-01-05 | Dsm Solutions, Inc. | Scalable process and structure of JFET for small and decreasing line widths |
DE10317383B4 (de) * | 2003-04-15 | 2008-10-16 | Infineon Technologies Ag | Sperrschicht-Feldeffekttransistor (JFET) mit Kompensationsgebiet und Feldplatte |
JP2006114886A (ja) * | 2004-09-14 | 2006-04-27 | Showa Denko Kk | n型III族窒化物半導体積層構造体 |
US7394158B2 (en) | 2004-10-21 | 2008-07-01 | Siliconix Technology C.V. | Solderable top metal for SiC device |
US7812441B2 (en) | 2004-10-21 | 2010-10-12 | Siliconix Technology C.V. | Schottky diode with improved surge capability |
US9419092B2 (en) | 2005-03-04 | 2016-08-16 | Vishay-Siliconix | Termination for SiC trench devices |
US7834376B2 (en) * | 2005-03-04 | 2010-11-16 | Siliconix Technology C. V. | Power semiconductor switch |
US7588961B2 (en) * | 2005-03-30 | 2009-09-15 | Nissan Motor Co., Ltd. | Semiconductor device and manufacturing method thereof |
JP4903439B2 (ja) * | 2005-05-31 | 2012-03-28 | 株式会社東芝 | 電界効果トランジスタ |
US8368165B2 (en) | 2005-10-20 | 2013-02-05 | Siliconix Technology C. V. | Silicon carbide Schottky diode |
US7372087B2 (en) * | 2006-06-01 | 2008-05-13 | Northrop Grumman Corporation | Semiconductor structure for use in a static induction transistor having improved gate-to-drain breakdown voltage |
KR101193453B1 (ko) | 2006-07-31 | 2012-10-24 | 비쉐이-실리코닉스 | 실리콘 카바이드 쇼트키 다이오드를 위한 몰리브덴 장벽 금속 및 제조방법 |
JP2009252889A (ja) * | 2008-04-03 | 2009-10-29 | Nec Electronics Corp | サージ保護素子 |
US7977713B2 (en) * | 2008-05-08 | 2011-07-12 | Semisouth Laboratories, Inc. | Semiconductor devices with non-punch-through semiconductor channels having enhanced conduction and methods of making |
TW201015718A (en) * | 2008-10-03 | 2010-04-16 | Sanyo Electric Co | Semiconductor device and method for manufacturing the same |
US8102012B2 (en) * | 2009-04-17 | 2012-01-24 | Infineon Technologies Austria Ag | Transistor component having a shielding structure |
US8058674B2 (en) * | 2009-10-07 | 2011-11-15 | Moxtek, Inc. | Alternate 4-terminal JFET geometry to reduce gate to source capacitance |
US8659057B2 (en) | 2010-05-25 | 2014-02-25 | Power Integrations, Inc. | Self-aligned semiconductor devices with reduced gate-source leakage under reverse bias and methods of making |
US20120068222A1 (en) * | 2010-09-21 | 2012-03-22 | Kabushiki Kaisha Toshiba | Semiconductor Device and Method for Manufacturing the Same |
CN102544091A (zh) * | 2010-12-17 | 2012-07-04 | 浙江大学 | 新型碳化硅mosfet |
WO2012102182A1 (en) | 2011-01-26 | 2012-08-02 | Semiconductor Energy Laboratory Co., Ltd. | Semiconductor device |
CN103348464B (zh) | 2011-01-26 | 2016-01-13 | 株式会社半导体能源研究所 | 半导体装置及其制造方法 |
TWI552345B (zh) | 2011-01-26 | 2016-10-01 | 半導體能源研究所股份有限公司 | 半導體裝置及其製造方法 |
US9691772B2 (en) | 2011-03-03 | 2017-06-27 | Semiconductor Energy Laboratory Co., Ltd. | Semiconductor memory device including memory cell which includes transistor and capacitor |
US9099437B2 (en) | 2011-03-08 | 2015-08-04 | Semiconductor Energy Laboratory Co., Ltd. | Semiconductor device |
JP5933300B2 (ja) | 2011-03-16 | 2016-06-08 | 株式会社半導体エネルギー研究所 | 半導体装置 |
JP5646044B2 (ja) * | 2011-03-30 | 2014-12-24 | 株式会社日立製作所 | 炭化珪素半導体装置およびその製造方法 |
US9184305B2 (en) | 2011-08-04 | 2015-11-10 | Avogy, Inc. | Method and system for a GAN vertical JFET utilizing a regrown gate |
US8969912B2 (en) | 2011-08-04 | 2015-03-03 | Avogy, Inc. | Method and system for a GaN vertical JFET utilizing a regrown channel |
US9006800B2 (en) | 2011-12-14 | 2015-04-14 | Avogy, Inc. | Ingan ohmic source contacts for vertical power devices |
CN103165443B (zh) * | 2011-12-16 | 2016-02-10 | 上海华虹宏力半导体制造有限公司 | 一种绝缘栅晶体管器件及其制造工艺方法 |
JP2013219207A (ja) * | 2012-04-10 | 2013-10-24 | Sumitomo Electric Ind Ltd | 電力用半導体装置およびその製造方法 |
US8981432B2 (en) * | 2012-08-10 | 2015-03-17 | Avogy, Inc. | Method and system for gallium nitride electronic devices using engineered substrates |
US20140055901A1 (en) * | 2012-08-25 | 2014-02-27 | North Carolina State University | Solid state fault isolation devices and methods |
KR20140067524A (ko) * | 2012-11-26 | 2014-06-05 | 삼성전자주식회사 | 파워소자의 웨이퍼 레벨 패키징 방법 |
EP2973669A4 (en) * | 2013-03-15 | 2016-11-09 | United Silicon Carbide Inc | IMPROVED VJFET DEVICES |
US9647125B2 (en) | 2013-05-20 | 2017-05-09 | Semiconductor Energy Laboratory Co., Ltd. | Semiconductor device and method for manufacturing the same |
JP6148070B2 (ja) * | 2013-05-27 | 2017-06-14 | ルネサスエレクトロニクス株式会社 | 縦チャネル型ジャンクションSiCパワーFETおよびその製造方法 |
US9425327B2 (en) | 2013-11-18 | 2016-08-23 | Infineon Technologies Ag | Junction field effect transistor cell with lateral channel region |
US9548399B2 (en) * | 2013-11-18 | 2017-01-17 | Infineon Technologies Ag | Junction field effect transistor cell with lateral channel region |
US9711660B2 (en) * | 2014-03-13 | 2017-07-18 | Infineon Technologies Ag | JFET and method of manufacturing thereof |
JP2016032014A (ja) * | 2014-07-29 | 2016-03-07 | 日本電信電話株式会社 | 窒化物半導体装置の製造方法 |
US10396215B2 (en) | 2015-03-10 | 2019-08-27 | United Silicon Carbide, Inc. | Trench vertical JFET with improved threshold voltage control |
JP6509621B2 (ja) * | 2015-04-22 | 2019-05-08 | ルネサスエレクトロニクス株式会社 | 半導体装置 |
US10446695B2 (en) | 2015-10-21 | 2019-10-15 | United Silicone Carbide, Inc. | Planar multi-implanted JFET |
US9653618B1 (en) * | 2015-10-21 | 2017-05-16 | United Silicon Carbide, Inc. | Planar triple-implanted JFET |
US10276667B1 (en) * | 2018-05-31 | 2019-04-30 | Silanna Asia Pte Ltd | High voltage breakdown tapered vertical conduction junction transistor |
US11233157B2 (en) * | 2018-09-28 | 2022-01-25 | General Electric Company | Systems and methods for unipolar charge balanced semiconductor power devices |
CN114730712A (zh) | 2019-11-08 | 2022-07-08 | 日清纺微电子有限公司 | 半导体装置 |
Citations (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS51135381A (en) * | 1975-05-19 | 1976-11-24 | Matsushita Electronics Corp | Semiconductor device and its manufacturing method |
EP0053854A1 (en) * | 1980-12-10 | 1982-06-16 | Philips Electronics Uk Limited | High voltage semiconductor devices |
JPH04276664A (ja) * | 1991-03-04 | 1992-10-01 | Toyota Central Res & Dev Lab Inc | 静電誘導形半導体装置 |
JP2000115912A (ja) | 1998-10-02 | 2000-04-21 | Honda Motor Co Ltd | ハイブリッド車両の制御装置 |
JP2000150912A (ja) * | 1998-11-05 | 2000-05-30 | Hitachi Ltd | 静電誘導トランジスタ |
JP2000252475A (ja) * | 1999-03-03 | 2000-09-14 | Kansai Electric Power Co Inc:The | 電圧制御型半導体装置とその製法及びそれを用いた電力変換装置 |
JP2000269518A (ja) * | 1999-03-18 | 2000-09-29 | Toshiba Corp | 電力用半導体素子及び半導体層の形成方法 |
JP2001144292A (ja) * | 1999-11-17 | 2001-05-25 | Denso Corp | 炭化珪素半導体装置 |
JP2001196602A (ja) * | 2000-01-12 | 2001-07-19 | Hitachi Ltd | 静電誘導トランジスタ |
EP1119054A1 (en) * | 1998-09-30 | 2001-07-25 | Hitachi, Ltd. | Electrostatic induction transistor |
US20010024138A1 (en) * | 1998-09-25 | 2001-09-27 | Karl-Otto Dohnke | Electronic switching device having at least two semiconductor components |
Family Cites Families (23)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4454523A (en) * | 1981-03-30 | 1984-06-12 | Siliconix Incorporated | High voltage field effect transistor |
JPS59150474A (ja) * | 1983-02-04 | 1984-08-28 | Toshiba Corp | 半導体装置 |
JPS6038885A (ja) * | 1983-08-11 | 1985-02-28 | Nippon Telegr & Teleph Corp <Ntt> | 縦形電界効果トランジスタ及びその製法 |
JPH01286367A (ja) * | 1988-05-12 | 1989-11-17 | Nec Corp | 縦型電界効果トランジスタ |
JPH06310536A (ja) * | 1993-02-22 | 1994-11-04 | Sumitomo Electric Ind Ltd | 電界効果トランジスタおよびその製造方法 |
US5723890A (en) * | 1994-01-07 | 1998-03-03 | Fuji Electric Co., Ltd. | MOS type semiconductor device |
JP3158973B2 (ja) * | 1995-07-20 | 2001-04-23 | 富士電機株式会社 | 炭化けい素縦型fet |
DE19548443A1 (de) * | 1995-12-22 | 1997-06-26 | Siemens Ag | Halbleiteranordnung zur Strombegrenzung |
JP3426928B2 (ja) * | 1996-09-18 | 2003-07-14 | 株式会社東芝 | 電力用半導体装置 |
US5714777A (en) * | 1997-02-19 | 1998-02-03 | International Business Machines Corporation | Si/SiGe vertical junction field effect transistor |
JP3641547B2 (ja) * | 1998-03-25 | 2005-04-20 | 株式会社豊田中央研究所 | 横型mos素子を含む半導体装置 |
DE19925233A1 (de) * | 1998-06-08 | 1999-12-09 | Siemens Ag | Halbleiteranordnung mit ohmscher Kontaktierung und Verfahren zur Kontaktierung einer Halbleiteranordnung |
US6281521B1 (en) * | 1998-07-09 | 2001-08-28 | Cree Research Inc. | Silicon carbide horizontal channel buffered gate semiconductor devices |
EP0981166A3 (en) * | 1998-08-17 | 2000-04-19 | ELMOS Semiconductor AG | JFET transistor |
DE19842488A1 (de) * | 1998-09-16 | 2000-03-30 | Siemens Ag | Halbleitervorrichtung und Halbleiterstruktur mit Kontaktierung |
JP3666280B2 (ja) * | 1999-01-20 | 2005-06-29 | 富士電機ホールディングス株式会社 | 炭化けい素縦形fetおよびその製造方法 |
JP3921862B2 (ja) * | 1999-02-05 | 2007-05-30 | 富士電機ホールディングス株式会社 | 炭化けい素縦形fetの製造方法 |
JP3356162B2 (ja) * | 1999-10-19 | 2002-12-09 | 株式会社デンソー | 半導体装置及びその製造方法 |
JP3338683B2 (ja) * | 2000-01-12 | 2002-10-28 | 株式会社日立製作所 | 炭化珪素半導体装置およびそれを用いた電力変換器 |
US6784486B2 (en) * | 2000-06-23 | 2004-08-31 | Silicon Semiconductor Corporation | Vertical power devices having retrograded-doped transition regions therein |
JP3812421B2 (ja) * | 2001-06-14 | 2006-08-23 | 住友電気工業株式会社 | 横型接合型電界効果トランジスタ |
JP4421144B2 (ja) * | 2001-06-29 | 2010-02-24 | 株式会社東芝 | 半導体装置 |
US6841812B2 (en) * | 2001-11-09 | 2005-01-11 | United Silicon Carbide, Inc. | Double-gated vertical junction field effect power transistor |
-
2002
- 2002-07-24 JP JP2002215804A patent/JP4122880B2/ja not_active Expired - Fee Related
-
2003
- 2003-07-24 CN CNB038154064A patent/CN100349270C/zh not_active Expired - Fee Related
- 2003-07-24 US US10/522,278 patent/US7282760B2/en not_active Expired - Fee Related
- 2003-07-24 TW TW092120250A patent/TWI288480B/zh not_active IP Right Cessation
- 2003-07-24 EP EP11173821A patent/EP2378546A3/en not_active Withdrawn
- 2003-07-24 EP EP11173822A patent/EP2378560A3/en not_active Withdrawn
- 2003-07-24 EP EP11163899A patent/EP2367205A3/en not_active Withdrawn
- 2003-07-24 EP EP03765376A patent/EP1542270A4/en not_active Withdrawn
- 2003-07-24 WO PCT/JP2003/009412 patent/WO2004010489A1/ja active Application Filing
- 2003-07-24 KR KR1020057000626A patent/KR100678251B1/ko not_active IP Right Cessation
-
2007
- 2007-06-28 US US11/770,414 patent/US7750377B2/en not_active Expired - Fee Related
Patent Citations (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS51135381A (en) * | 1975-05-19 | 1976-11-24 | Matsushita Electronics Corp | Semiconductor device and its manufacturing method |
EP0053854A1 (en) * | 1980-12-10 | 1982-06-16 | Philips Electronics Uk Limited | High voltage semiconductor devices |
JPH04276664A (ja) * | 1991-03-04 | 1992-10-01 | Toyota Central Res & Dev Lab Inc | 静電誘導形半導体装置 |
US20010024138A1 (en) * | 1998-09-25 | 2001-09-27 | Karl-Otto Dohnke | Electronic switching device having at least two semiconductor components |
EP1119054A1 (en) * | 1998-09-30 | 2001-07-25 | Hitachi, Ltd. | Electrostatic induction transistor |
JP2000115912A (ja) | 1998-10-02 | 2000-04-21 | Honda Motor Co Ltd | ハイブリッド車両の制御装置 |
JP2000150912A (ja) * | 1998-11-05 | 2000-05-30 | Hitachi Ltd | 静電誘導トランジスタ |
JP2000252475A (ja) * | 1999-03-03 | 2000-09-14 | Kansai Electric Power Co Inc:The | 電圧制御型半導体装置とその製法及びそれを用いた電力変換装置 |
JP2000269518A (ja) * | 1999-03-18 | 2000-09-29 | Toshiba Corp | 電力用半導体素子及び半導体層の形成方法 |
JP2001144292A (ja) * | 1999-11-17 | 2001-05-25 | Denso Corp | 炭化珪素半導体装置 |
JP2001196602A (ja) * | 2000-01-12 | 2001-07-19 | Hitachi Ltd | 静電誘導トランジスタ |
Non-Patent Citations (1)
Title |
---|
See also references of EP1542270A4 * |
Also Published As
Publication number | Publication date |
---|---|
TW200403850A (en) | 2004-03-01 |
US7282760B2 (en) | 2007-10-16 |
EP2367205A3 (en) | 2012-03-28 |
TWI288480B (en) | 2007-10-11 |
EP1542270A1 (en) | 2005-06-15 |
US20070278540A1 (en) | 2007-12-06 |
EP2367205A2 (en) | 2011-09-21 |
CN100349270C (zh) | 2007-11-14 |
EP2378560A3 (en) | 2012-04-18 |
KR20050021471A (ko) | 2005-03-07 |
US20050230715A1 (en) | 2005-10-20 |
JP2004063507A (ja) | 2004-02-26 |
KR100678251B1 (ko) | 2007-02-02 |
EP2378546A2 (en) | 2011-10-19 |
EP2378546A3 (en) | 2013-03-06 |
JP4122880B2 (ja) | 2008-07-23 |
EP1542270A4 (en) | 2009-07-22 |
US7750377B2 (en) | 2010-07-06 |
EP2378560A2 (en) | 2011-10-19 |
CN1666325A (zh) | 2005-09-07 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
WO2004010489A1 (ja) | 縦型接合型電界効果トランジスタ、及び縦型接合型電界効果トランジスタの製造方法 | |
US10679983B2 (en) | Method of producing a semiconductor device | |
US9876103B2 (en) | Semiconductor device and transistor cell having a diode region | |
US9640652B2 (en) | Semiconductor devices including epitaxial layers and related methods | |
JP5295274B2 (ja) | イオン注入及び側方拡散による炭化シリコンパワーデバイスの自己整列的な製造方法 | |
JP3216804B2 (ja) | 炭化けい素縦形fetの製造方法および炭化けい素縦形fet | |
US7705362B2 (en) | Silicon carbide devices with hybrid well regions | |
JP2000150866A (ja) | 炭化けい素nチャネルMOS半導体素子およびその製造方法 | |
JP3939583B2 (ja) | 電界効果トランジスタの製造方法 | |
JP2000228528A (ja) | 炭化けい素縦形fetおよびその製造方法 | |
JP4045893B2 (ja) | 縦型接合型電界効果トランジスタ | |
US10103259B2 (en) | Method of manufacturing a wide bandgap vertical-type MOSFET | |
JP2021010027A (ja) | 半導体装置および半導体装置の製造方法 | |
JP3541832B2 (ja) | 電界効果トランジスタ及びその製造方法 | |
JP4192469B2 (ja) | 接合型電界効果トランジスタ、及び接合型電界効果トランジスタの製造方法 | |
JP2003209123A (ja) | 縦型接合型電界効果トランジスタ、及び縦型接合型電界効果トランジスタの製造方法 | |
JP2000286414A (ja) | Mosデバイス、およびその製造方法 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): CN KR US |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LU MC NL PT RO SE SI SK TR |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
WWE | Wipo information: entry into national phase |
Ref document number: 20038154064 Country of ref document: CN |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1020057000626 Country of ref document: KR |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2003765376 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 10522278 Country of ref document: US |
|
WWP | Wipo information: published in national office |
Ref document number: 1020057000626 Country of ref document: KR |
|
WWP | Wipo information: published in national office |
Ref document number: 2003765376 Country of ref document: EP |