WO2002099889A9 - Trench schottky rectifier - Google Patents
Trench schottky rectifierInfo
- Publication number
- WO2002099889A9 WO2002099889A9 PCT/US2002/017322 US0217322W WO02099889A9 WO 2002099889 A9 WO2002099889 A9 WO 2002099889A9 US 0217322 W US0217322 W US 0217322W WO 02099889 A9 WO02099889 A9 WO 02099889A9
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- region
- semiconductor
- face
- semiconductor region
- insulating
- Prior art date
Links
- 239000004065 semiconductor Substances 0.000 claims abstract description 65
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 25
- 238000000034 method Methods 0.000 claims description 24
- 238000005229 chemical vapour deposition Methods 0.000 claims description 13
- 238000000151 deposition Methods 0.000 claims description 13
- 235000012239 silicon dioxide Nutrition 0.000 claims description 10
- 239000000377 silicon dioxide Substances 0.000 claims description 10
- 239000000758 substrate Substances 0.000 claims description 9
- 230000008021 deposition Effects 0.000 claims description 7
- 230000000873 masking effect Effects 0.000 claims description 5
- 238000005530 etching Methods 0.000 claims description 4
- 229910052710 silicon Inorganic materials 0.000 claims description 4
- 239000010703 silicon Substances 0.000 claims description 3
- 230000004888 barrier function Effects 0.000 description 12
- 230000015556 catabolic process Effects 0.000 description 9
- 230000003647 oxidation Effects 0.000 description 9
- 238000007254 oxidation reaction Methods 0.000 description 9
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 7
- BOTDANWDWHJENH-UHFFFAOYSA-N Tetraethyl orthosilicate Chemical compound CCO[Si](OCC)(OCC)OCC BOTDANWDWHJENH-UHFFFAOYSA-N 0.000 description 6
- 230000000903 blocking effect Effects 0.000 description 6
- 239000001301 oxygen Substances 0.000 description 6
- 229910052760 oxygen Inorganic materials 0.000 description 6
- 239000010936 titanium Substances 0.000 description 6
- 230000005684 electric field Effects 0.000 description 5
- 239000002184 metal Substances 0.000 description 5
- 229910052751 metal Inorganic materials 0.000 description 5
- 230000008569 process Effects 0.000 description 5
- 230000008901 benefit Effects 0.000 description 4
- 230000007547 defect Effects 0.000 description 4
- 230000001419 dependent effect Effects 0.000 description 4
- 229920002120 photoresistant polymer Polymers 0.000 description 4
- 238000001505 atmospheric-pressure chemical vapour deposition Methods 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 238000004518 low pressure chemical vapour deposition Methods 0.000 description 3
- 238000000623 plasma-assisted chemical vapour deposition Methods 0.000 description 3
- 229910021420 polycrystalline silicon Inorganic materials 0.000 description 3
- 229920005591 polysilicon Polymers 0.000 description 3
- GQPLMRYTRLFLPF-UHFFFAOYSA-N Nitrous Oxide Chemical compound [O-][N+]#N GQPLMRYTRLFLPF-UHFFFAOYSA-N 0.000 description 2
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical group [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 2
- 230000008878 coupling Effects 0.000 description 2
- 238000010168 coupling process Methods 0.000 description 2
- 238000005859 coupling reaction Methods 0.000 description 2
- 239000002019 doping agent Substances 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 229910052719 titanium Inorganic materials 0.000 description 2
- MAKDTFFYCIMFQP-UHFFFAOYSA-N titanium tungsten Chemical compound [Ti].[W] MAKDTFFYCIMFQP-UHFFFAOYSA-N 0.000 description 2
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 2
- 229910052721 tungsten Inorganic materials 0.000 description 2
- 239000010937 tungsten Substances 0.000 description 2
- 229910001218 Gallium arsenide Inorganic materials 0.000 description 1
- 229910003915 SiCl2H2 Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000002800 charge carrier Substances 0.000 description 1
- 238000000280 densification Methods 0.000 description 1
- MROCJMGDEKINLD-UHFFFAOYSA-N dichlorosilane Chemical compound Cl[SiH2]Cl MROCJMGDEKINLD-UHFFFAOYSA-N 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000000407 epitaxy Methods 0.000 description 1
- 229910052732 germanium Inorganic materials 0.000 description 1
- 238000005468 ion implantation Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910003465 moissanite Inorganic materials 0.000 description 1
- 239000001272 nitrous oxide Substances 0.000 description 1
- 238000001020 plasma etching Methods 0.000 description 1
- 238000005036 potential barrier Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 229910000077 silane Inorganic materials 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 238000009279 wet oxidation reaction Methods 0.000 description 1
Classifications
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- 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
- H01L29/40—Electrodes ; Multistep manufacturing processes therefor
- H01L29/41—Electrodes ; Multistep manufacturing processes therefor characterised by their shape, relative sizes or dispositions
- H01L29/417—Electrodes ; Multistep manufacturing processes therefor characterised by their shape, relative sizes or dispositions carrying the current to be rectified, amplified or switched
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/02—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier
- H01L27/04—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being a semiconductor body
- H01L27/08—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being a semiconductor body including only semiconductor components of a single kind
- H01L27/0817—Thyristors only
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/02—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier
- H01L27/04—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being a semiconductor body
- H01L27/08—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being a semiconductor body including only semiconductor components of a single kind
- H01L27/085—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being a semiconductor body including only semiconductor components of a single kind including field-effect components only
- H01L27/095—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being a semiconductor body including only semiconductor components of a single kind including field-effect components only the components being Schottky barrier gate field-effect 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
- H01L29/66—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
- H01L29/66083—Multistep manufacturing processes of devices having semiconductor bodies comprising group 14 or group 13/15 materials the devices being controllable only by variation of the electric current supplied or the electric potential applied, to one or more of the electrodes carrying the current to be rectified, amplified, oscillated or switched, e.g. two-terminal devices
- H01L29/6609—Diodes
- H01L29/66143—Schottky diodes
-
- 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
- H01L29/86—Types of semiconductor device ; Multistep manufacturing processes therefor controllable only by variation of the electric current supplied, or only the electric potential applied, to one or more of the electrodes carrying the current to be rectified, amplified, oscillated or switched
- H01L29/861—Diodes
- H01L29/872—Schottky diodes
-
- 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
- H01L29/86—Types of semiconductor device ; Multistep manufacturing processes therefor controllable only by variation of the electric current supplied, or only the electric potential applied, to one or more of the electrodes carrying the current to be rectified, amplified, oscillated or switched
- H01L29/861—Diodes
- H01L29/872—Schottky diodes
- H01L29/8725—Schottky diodes of the trench MOS barrier type [TMBS]
-
- 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
- H01L29/40—Electrodes ; Multistep manufacturing processes therefor
- H01L29/41—Electrodes ; Multistep manufacturing processes therefor characterised by their shape, relative sizes or dispositions
- H01L29/423—Electrodes ; Multistep manufacturing processes therefor characterised by their shape, relative sizes or dispositions not carrying the current to be rectified, amplified or switched
- H01L29/42312—Gate electrodes for field effect devices
- H01L29/42316—Gate electrodes for field effect devices for field-effect transistors
- H01L29/4232—Gate electrodes for field effect devices for field-effect transistors with insulated gate
- H01L29/42364—Gate electrodes for field effect devices for field-effect transistors with insulated gate characterised by the insulating layer, e.g. thickness or uniformity
Definitions
- This invention relates to rectifiers and more particularly to Schottky barrier rectifying devices, and methods of forming these devices.
- Rectifiers exhibit relatively low resistance to current flow in a forward direction and a high resistance to current flow in a reverse direction.
- Schottky barrier rectifiers are a type of rectifier that have found use as output rectifiers in switching-mode power supplies and in other high-speed power switching applications, such as motor drives. These devices are capable of carrying large forward currents and supporting large reverse blocking voltages.
- rectifier 10 includes a semiconductor substrate 12 of first conductivity type, typically N-type conductivity, having a first face 12a and a second opposing face 12b.
- the substrate 12 comprises a relatively highly doped cathode region 12c (shown as N+) adjacent the first face 12a.
- a drift region 12d of first conductivity type (shown as N) extends from the cathode region 12c to the second face 12b. Accordingly, the doping concentration of the cathode region 12c is greater than that of the drift region 12d.
- the mesa can be of stripe, rectangular, cylindrical or other similar geometry. Insulating regions 16a and 16b (described as Si0 2 ) are also provided on the mesa sides.
- the rectifier also includes an anode electrode 18 on the insulating regions 16a, 16b.
- the anode electrode 18 forms a Schottky rectifying contact with the mesa 14 at second face 12b.
- the height of the Schottky barrier formed at the anode electrode/mesa interface is dependent on the type of electrode metal and semiconductor (e.g., Si, Ge, GaAs, and SiC) used and is also dependent on the doping concentration in the mesa 14.
- a cathode electrode 20 is provided adjacent the cathode region 12c at the first face 12a. The cathode electrode 20 ohmically contacts cathode region 12c.
- the on-state voltage drop is generally dependent on the forward voltage drop across the metal/semiconductor junction and the series resistance of the semiconductor region and cathode contact.
- the need for reduced power consumption also generally requires minimizing the reverse-biased leakage current.
- the reverse-biased leakage current is the current in the rectifier during a reverse-biased blocking mode of operation.
- the semiconductor portion of the rectifier is typically lightly doped and made relatively thick so that the reverse-biased electric field at the metal/semiconductor interface does not become excessive.
- the magnitude of the reverse-biased leakage current for a given reverse-biased voltage is also inversely dependent on the Schottky barrier height (potential barrier) between the metal and semiconductor regions. Accordingly, to achieve reduced power consumption, both the forward-biased voltage drop and reverse-biased leakage current should be minimized and the reverse blocking voltage should be maximized.
- the peak in the electric field profile shifts away from the metal-semiconductor contact and into the drift region.
- the mesa is able to support more voltage, and thus provides higher breakdown voltages (reverse blocking voltages) than those of an ideal parallel-plane rectifier.
- FIG. 2 A graphical illustration of the breakdown voltage versus trench oxide thickness for the Schottky rectifier shown in FIG. 1 is illustrated in FIG. 2, which is a reproduction of FIG. 12 of the aforementioned patent.
- the breakdown voltage is shown as monotonically increasing with oxide thickness up to at least 2200 Angstroms.
- the graphical illustration of FIG. 2 was obtained for a Schottky rectifier having a mesa width and cell pitch of 0.5 microns and 1 micron, respectively, and a trench depth and drift region thickness of 3 microns and 4 microns, respectively.
- FIG. 2 indicates, Schottky rectifiers to be used in high voltage applications require a relatively thick trench oxide layer.
- the oxide layer is typically grown by a thermal technique, which is advantageous employed because it provides good epitaxy with a reduced defect density at the oxide-semiconductor interface.
- thermally grown oxide layers make it difficult to achieve a trench oxide layer with a thickness upwards of 2000 Angstroms.
- alternative growth techniques such as chemical vapor deposition (CVD), while having greater deposition rates, produce a greater defect density and hence a higher charge at the oxide-semiconductor interface.
- CVD chemical vapor deposition
- a Schottky rectifier which comprises: (a) a semiconductor region having first and second opposing faces, with the semiconductor region comprising a cathode region of first conductivity type adjacent the first face and a drift region of the first conductivity type adjacent the second face, and with the drift region having a lower net doping concentration than that of the cathode region; (b) one or more trenches extending from the second face into the semiconductor region and defining one or more mesas within the semiconductor region; (c) an insulating region adjacent the semiconductor region in lower portions of the trench; (d) and an anode electrode that is (i) adjacent to and forms a Schottky rectifying contact with the semiconductor region at the second face, (ii) adjacent to and forms a Schottky rectifying contact with the semiconductor region within upper portions of the trench and (iii) adjacent to the insulating region within the lower portions of the trench.
- the semiconductor is silicon
- the first conductivity type is n- type conductivity
- a cathode electrode is provided on the first face.
- the lower portions of the trenches preferably correspond to approximately 25 to 40% of the depth of the trenches.
- the trench extends into the cathode region, with the insulated lower portions of the trench preferably extending between the cathode region and the drift region.
- the insulating region preferably comprises silicon dioxide, which can be either deposited or thermally grown.
- a polysilicon region is disposed on the insulating region and forms part of the anode electrode.
- the present invention also provides a method of forming a trench Schottky rectifier.
- the method comprises: (a) forming a semiconductor region having first and second opposing faces, with the semiconductor region comprising a cathode region of first conductivity type adjacent the first face and a drift region of the first conductivity type adjacent the second face, and with the drift region having a lower net doping concentration than that of the cathode region; (b) forming one or more trenches extending from the second face into the semiconductor region, with the trenches defining one or more mesas within the semiconductor region; (c) forming an insulating region adjacent the semiconductor region in lower portions of the trench; (d) and forming an anode electrode that is (i) adjacent to and forms a Schottky rectifying contact with the semiconductor region at the second face, (ii) adjacent to and forms a Schottky rectifying contact with the semiconductor region within upper portions of the trench and (iii) adjacent to the insulating region within the lower portions of the trench.
- the step of forming the semiconductor region preferably comprises providing a semiconductor substrate that corresponds to the cathode region, and growing an epitaxial semiconductor layer that corresponds to the drift region on the substrate.
- the step of forming the trenches preferably comprises the steps of forming a patterned masking layer over the second face of the semiconductor region and etching the trenches through the masking layer.
- the step of forming the insulating region can comprise providing an oxide layer over the second face and in the trenches, and subsequently etching portions of the oxide layer.
- a photoresist pattern is provided on the oxide layer (which can be thermally grown), and portions of the oxide layer not covered by the photoresist etched, whereupon the photoresist is removed.
- a polysilicon layer is provided on the oxide layer (which can be thermally grown), and the polysilicon layer is etched such that portions of the oxide layer over the second face and over the upper portions of the trenches are exposed, and these exposed portions are subsequently removed by etching.
- the step of forming the insulating region can also comprise depositing an oxide layer.
- a tetraethylorthosilicate layer can be deposited on the second face and within the trenches.
- the tetraethylorthosilicate layer can then be etched until it is removed from the second surface and the upper portions of the trenches. Subsequently, the tetraethylorthosilicate can be converted into a high- density silicon dioxide layer.
- One advantage of the present invention is that a novel Schottky barrier rectifier is provided having low forward-biased voltage drop, low reverse-biased leakage current and high breakdown voltage.
- Another advantage is that such a Schottky barrier rectifier can be made using simple, and thus economical, manufacturing techniques.
- FIG. 1 illustrates a cross-sectional representation of a trench MOS barrier Schottky rectifier according to the prior art.
- FIG. 2 is a graphical illustration of breakdown voltage versus trench oxide thickness for a Schottky rectifier such as shown in FIG. 1.
- FIG. 3 is a cross-sectional representation of a trench Schottky rectifier according to an embodiment of the present invention.
- FIG. 4 is a cross-sectional representation of a trench Schottky rectifier according to an embodiment of the present invention.
- FIG. 5 is a cross-sectional representation of a trench Schottky rectifier according to an embodiment of the present invention.
- FIG. 6 is a cross-sectional representation of a trench Schottky rectifier according to an embodiment of the present invention.
- FIGS 7A-7B are cross sectional views illustrating a method of forming the trench Schottky rectifier of FIG. 3, according to an embodiment of the invention.
- the rectifier 10 includes a semiconductor region 12 of first conductivity type, typically N-type conductivity, having a first face 12a and second opposing faces 12b.
- the substrate semiconductor region 12 preferably comprises a relatively highly doped cathode region 12c (shown as N+) adjacent first face 12a.
- the cathode region 12c is doped to a first conductivity type dopant concentration of about 5xl0 19 /cm 3 .
- a drift region 12d of first conductivity type (shown as N) preferably extends from the cathode region 12c to second faces 12b.
- the drift region 12d is doped to a first conductivity type dopant concentration of about 3.3x10 /cm for a 30 Volt device.
- Drift region 12d and cathode region 12c form a non-rectifying N+/N junction.
- ⁇ Mesas 14 having cross-sectional width "Wm " are formed in the drift region 12d. Mesas are defined by opposing trenches. Insulating regions 16 (in this case, shown as thermally grown oxide layers) are formed within the trenches and are adjacent the semiconductor region 12. Each insulating region 16 includes first and second insulating regions 16a and 16b. Insulating region 16a is a thermally grown layer. Insulating region 16b is grown over insulating region 16a by a deposition technique. As explained below, the thermally grown region advantageously produces an oxide-semiconductor interface with relatively few defects while the deposited region allows a relatively thick trench oxide layer to be grown. Insulating regions 16 typically have a total thickness on the order of about 700 to 2000 Angstroms. Wm is typically on the order of 1 micron. Trench depth "d" is typically on the order of 3 microns.
- Mesas 14 extend in a third dimension (not shown) and can be of stripe, rectangular, cylindrical or other similar geometry. Hence, as will be understood by those skilled in the art, mesas 14 can be formed in the semiconductor region 12 using numerous trench configurations. [0034] For example, mesa 14 can be formed between pairs of adjacent linear trenches that extend in a third dimension. As another example, an annular-shaped trench can form mesa 14. For both of these examples, when viewed in transverse cross section, the trenches will appear as shown in FIG. 3.
- Anode electrode 18 is found immediately adjacent to the drain region
- Anode electrode 18 is also found immediately adjacent to the insulating regions 16. Anode electrode 18 forms a Schottky barrier rectifying junction where it contacts the semiconductor drain region 12d, i.e., along second faces 12b.
- a cathode electrode (not shown) is provided adjacent the cathode region 12c at the first face 12a.
- the cathode electrode preferably ohmically contacts the cathode region 12c.
- Such a rectifier has a high reverse bias breakdown voltage. Without wishing to be held to any particular theory of operation, it is believed that this design provides an insulating region 16 that causes charge coupling to occur between the anode electrode 18 and mesa 14, favorably affecting the voltage profiles within the mesa structure and providing high reverse bias breakdown voltages and low leakage currents. It is well within the skill of those in the art to optimize the thickness of first insulating layer 16a relative to the thickness of the second insulating layer 16b.
- FIG. 4 Another embodiment of the present invention is provided in FIG. 4.
- This embodiment is similar to that of FIG. 3, except that the trenches extend beyond drift regions 12d and into cathode region 12c.
- the Schottky rectifying characteristics of the contact between the anode electrode and the drift region 12d are improved by using a multi-layer anode electrode, which comprises a titanium layer 18a, a titanium-tungsten layer 18b and a tungsten layer 18c.
- the titanium-tungsten layer 18b comprises 50% titanium and 50% tungsten. Further improvements in forward biased voltage drop are made by forming P+ regions 12e within the device (see
- FIGS. 7A-7B illustrate an embodiment of the present invention for providing the trench Schottky rectifier 10 shown in FIG. 3.
- an N-doped epitaxial layer (corresponding to drift region 12d) is grown on a conventionally N+ doped substrate (corresponding to cathode region 12c).
- Epitaxial layer 12d is typically about 7 microns thick.
- a photoresist masking process is used to form mask portions (not shown), which define the location of trenches 21.
- Trenches 21 are preferably dry etched through openings between mask portions by reactive ion etching, typically to a depth of about 3 microns.
- Mask portions are removed and an insulating layers 16a and 16b are formed over the surface of the entire structure by thermal growth and deposition, respectively.
- Insulating layers 16a and 16b are typically oxide layers such as silicon dioxide (Si0 2 ). Thicknesses in the vicinity of about 700 to 2000 Angstroms are typical for thermal oxide layer 16.
- silicon dioxide is formed from silicon (Si). Due to the presence of oxygen, this reaction takes place even at room temperature. However, elevated temperatures (typically between 900 and 1200 C) are generally required to achieve quality oxides in reasonable process times. Where oxygen is used as an oxygen source, the reaction is referred to as dry oxidation. Where water vapor is used as an oxygen source, the reaction is referred to as steam oxidation or wet oxidation. The growth rates associated with steam oxidation are greater that those associated with dry oxidation.
- Insulating layer 16b may be grown by a deposition technique such as chemical vapor deposition (CVD).
- CVD chemical vapor deposition
- APCVD atmospheric pressure chemical vapor deposition
- LPCVD low-pressure chemical vapor deposition
- PECVD plasma-enhanced CVD
- insulating layer 16b is silicon dioxide
- silane (SiH 4 ) and oxygen (0 2 ) are mixed and reacted in a deposition chamber, typically at about 450 C, forming Si0 2 .
- higher temperatures for example, about 900 C, are used to react dichlorosilane (SiCl 2 H 2 ) with nitrous oxide (N0 2 ) to form the Si0 2 .
- lower temperatures typically about 400 C, are used and Si0 2 is formed using tetraethyl orthosilicate (TEOS) (Si(OC 2 H 5 ) 4 ) sources in the presence of oxygen.
- TEOS tetraethyl orthosilicate
- the deposited CVD layer can be densified, for example, by a high temperature anneal step. After densification, the deposited silicon dioxide film is close to the structure and properties of a thermally grown oxide.
- a primary advantage of deposition techniques over thermal growth techniques is that the deposition techniques provide greater growth rates. As a result, a relatively thick trench oxide layer can be readily produced. Moreover, since a thermally grown layer is provided at the oxide-semiconductor interface, a thick oxide layer is achieved without producing an unduly high defect density at the interface. [0043] Finally, as shown in FIG. 7B, anode electrode 18 is provided to complete the structure.
- the anode electrode can be obtained by providing (a) a Ti:W layer, followed by (b) a P Si layer, followed by (c) an Al layer.
- the anode electrode can be obtained by providing (a) a Ti:N layer, followed by (b) a Pt:Si layer, followed by (c) an Al layer.
- FIG. 5 Yet another example of the anode electrode 18 structure is found in Figure 5 (see discussion above). In this example, the anode electrode is obtained by providing (a) Ti layer, followed by (b) a Ti:W layer, followed by (c) a W layer.
- the present invention thus provides a trench Schottky rectifier and methods of making the same.
- the resulting Schottky rectifier has a thick trench oxide layer and thus a high breakdown voltage.
Abstract
Description
Claims
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2003502893A JP4313190B2 (en) | 2001-06-01 | 2002-05-31 | Schottky rectifier |
KR1020037015603A KR100884077B1 (en) | 2001-06-01 | 2002-05-31 | Trench schottky rectifier |
EP02739587A EP1393379B1 (en) | 2001-06-01 | 2002-05-31 | Trench schottky rectifier |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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US09/872,926 | 2001-06-01 | ||
US09/872,926 US6580141B2 (en) | 2001-06-01 | 2001-06-01 | Trench schottky rectifier |
Publications (2)
Publication Number | Publication Date |
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WO2002099889A1 WO2002099889A1 (en) | 2002-12-12 |
WO2002099889A9 true WO2002099889A9 (en) | 2004-04-08 |
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Application Number | Title | Priority Date | Filing Date |
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PCT/US2002/017322 WO2002099889A1 (en) | 2001-06-01 | 2002-05-31 | Trench schottky rectifier |
Country Status (7)
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US (2) | US6580141B2 (en) |
EP (1) | EP1393379B1 (en) |
JP (1) | JP4313190B2 (en) |
KR (1) | KR100884077B1 (en) |
CN (1) | CN1280915C (en) |
TW (1) | TW548855B (en) |
WO (1) | WO2002099889A1 (en) |
Families Citing this family (37)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6707127B1 (en) * | 2000-08-31 | 2004-03-16 | General Semiconductor, Inc. | Trench schottky rectifier |
US7291884B2 (en) * | 2001-07-03 | 2007-11-06 | Siliconix Incorporated | Trench MIS device having implanted drain-drift region and thick bottom oxide |
US7009247B2 (en) * | 2001-07-03 | 2006-03-07 | Siliconix Incorporated | Trench MIS device with thick oxide layer in bottom of gate contact trench |
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DE102004058431B4 (en) * | 2003-12-05 | 2021-02-18 | Infineon Technologies Americas Corp. | III-nitride semiconductor device with trench structure |
US7098521B2 (en) * | 2004-10-01 | 2006-08-29 | International Business Machines Corporation | Reduced guard ring in schottky barrier diode structure |
DE102004056663A1 (en) * | 2004-11-24 | 2006-06-01 | Robert Bosch Gmbh | Semiconductor device and rectifier arrangement |
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US8039328B2 (en) * | 2005-10-18 | 2011-10-18 | International Rectifier Corporation | Trench Schottky device with single barrier |
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US20090053864A1 (en) * | 2007-08-23 | 2009-02-26 | Jinping Liu | Method for fabricating a semiconductor structure having heterogeneous crystalline orientations |
US7741693B1 (en) | 2007-11-16 | 2010-06-22 | National Semiconductor Corporation | Method for integrating trench MOS Schottky barrier devices into integrated circuits and related semiconductor devices |
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TWI455209B (en) | 2009-10-12 | 2014-10-01 | Pfc Device Co | Trench mos p-n junction schottky diode device and method for manufacturing the same |
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DE102010028203A1 (en) * | 2010-04-26 | 2011-10-27 | Robert Bosch Gmbh | Rectifier bridge circuit |
BR112013017505A2 (en) * | 2011-01-07 | 2016-09-27 | Infineon Technologies Austria | semiconductor device arrangement with a first semiconductor device and a plurality of second semiconductor devices |
JP2013030618A (en) | 2011-07-28 | 2013-02-07 | Rohm Co Ltd | Semiconductor device |
US9059329B2 (en) * | 2011-08-22 | 2015-06-16 | Monolithic Power Systems, Inc. | Power device with integrated Schottky diode and method for making the same |
GB2526951B (en) | 2011-11-23 | 2016-04-20 | Acorn Tech Inc | Improving metal contacts to group IV semiconductors by inserting interfacial atomic monolayers |
CN102916055B (en) * | 2012-10-11 | 2014-12-24 | 杭州立昂微电子股份有限公司 | Trenched Schottky-barrier diode and manufacturing method thereof |
CN103035751A (en) * | 2012-11-23 | 2013-04-10 | 上海华虹Nec电子有限公司 | Schottky diode |
JP5922014B2 (en) * | 2012-12-27 | 2016-05-24 | 新電元工業株式会社 | Trench Schottky barrier diode and manufacturing method thereof |
CN104183485B (en) * | 2013-05-23 | 2017-11-10 | 上海宝芯源功率半导体有限公司 | A kind of super barrier rectifier structure and preparation method thereof |
TWI514578B (en) * | 2013-06-21 | 2015-12-21 | Chip Integration Tech Co Ltd | Structure of dual trench rectifier and method of forming the same |
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US9620611B1 (en) | 2016-06-17 | 2017-04-11 | Acorn Technology, Inc. | MIS contact structure with metal oxide conductor |
WO2018094205A1 (en) | 2016-11-18 | 2018-05-24 | Acorn Technologies, Inc. | Nanowire transistor with source and drain induced by electrical contacts with negative schottky barrier height |
JP2017063237A (en) * | 2017-01-13 | 2017-03-30 | ローム株式会社 | Semiconductor device |
CN107256886A (en) * | 2017-07-12 | 2017-10-17 | 付妮娜 | Groove-type Schottky diode and preparation method thereof |
WO2019155768A1 (en) * | 2018-02-09 | 2019-08-15 | 三菱電機株式会社 | Power semiconductor device |
Family Cites Families (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS4822390B1 (en) * | 1969-03-18 | 1973-07-05 | ||
JPS5294773A (en) * | 1976-02-05 | 1977-08-09 | Sumitomo Electric Ind Ltd | Semiconductor element and its manufacture |
US4835580A (en) * | 1987-04-30 | 1989-05-30 | Texas Instruments Incorporated | Schottky barrier diode and method |
US5365102A (en) * | 1993-07-06 | 1994-11-15 | North Carolina State University | Schottky barrier rectifier with MOS trench |
US6078090A (en) * | 1997-04-02 | 2000-06-20 | Siliconix Incorporated | Trench-gated Schottky diode with integral clamping diode |
US5612567A (en) * | 1996-05-13 | 1997-03-18 | North Carolina State University | Schottky barrier rectifiers and methods of forming same |
US5883422A (en) * | 1996-06-28 | 1999-03-16 | The Whitaker Corporation | Reduced parasitic capacitance semiconductor devices |
JP3502531B2 (en) * | 1997-08-28 | 2004-03-02 | 株式会社ルネサステクノロジ | Method for manufacturing semiconductor device |
US6184563B1 (en) * | 1998-07-27 | 2001-02-06 | Ho-Yuan Yu | Device structure for providing improved Schottky barrier rectifier |
US6252258B1 (en) * | 1999-08-10 | 2001-06-26 | Rockwell Science Center Llc | High power rectifier |
JP2001085686A (en) * | 1999-09-13 | 2001-03-30 | Mitsubishi Electric Corp | Semiconductor device and its manufacturing method |
JP2001094094A (en) * | 1999-09-21 | 2001-04-06 | Hitachi Ltd | Semiconductor device and fabrication method thereof |
-
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TW548855B (en) | 2003-08-21 |
EP1393379B1 (en) | 2011-12-21 |
KR20040005998A (en) | 2004-01-16 |
CN1520615A (en) | 2004-08-11 |
US20020179993A1 (en) | 2002-12-05 |
US6580141B2 (en) | 2003-06-17 |
JP4313190B2 (en) | 2009-08-12 |
KR100884077B1 (en) | 2009-02-19 |
WO2002099889A1 (en) | 2002-12-12 |
CN1280915C (en) | 2006-10-18 |
JP2004529506A (en) | 2004-09-24 |
EP1393379A4 (en) | 2009-08-12 |
US20030193074A1 (en) | 2003-10-16 |
EP1393379A1 (en) | 2004-03-03 |
US6770548B2 (en) | 2004-08-03 |
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