CA1286794C - Apparatus for dry processing a semiconductor wafer - Google Patents
Apparatus for dry processing a semiconductor waferInfo
- Publication number
- CA1286794C CA1286794C CA000561382A CA561382A CA1286794C CA 1286794 C CA1286794 C CA 1286794C CA 000561382 A CA000561382 A CA 000561382A CA 561382 A CA561382 A CA 561382A CA 1286794 C CA1286794 C CA 1286794C
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- Canada
- Prior art keywords
- fluid
- chamber
- processing
- pressure
- liquid
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
-
- 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
- H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
- H01L21/67005—Apparatus not specifically provided for elsewhere
- H01L21/67011—Apparatus for manufacture or treatment
- H01L21/67017—Apparatus for fluid treatment
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/26—Processing photosensitive materials; Apparatus therefor
- G03F7/265—Selective reaction with inorganic or organometallic reagents after image-wise exposure, e.g. silylation
-
- 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
- H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
- H01L21/67005—Apparatus not specifically provided for elsewhere
- H01L21/67011—Apparatus for manufacture or treatment
- H01L21/67098—Apparatus for thermal treatment
- H01L21/67109—Apparatus for thermal treatment mainly by convection
Abstract
APPARATUS FOR DRY PROCESSING A SEMICONDUCTOR WAFER
Abstract of the Disclosure A method and apparatus of dry processing a semiconductor wafer including processes of vacuum baking and dry silylation provides a gaseous atmosphere of pressure up to 760 Torr against the surface of the wafer, one or more of the constituents of the gas being obtained from a liquid fluid source of the constituent, including a metering device that controls flow of the liquid fluid from a remote reservoir and feeds it to a vaporizer that converts the fluid to a vapor gas at pressure up to 760 Torr and feeds the vapor gas at that pressure into a wafer processing chamber where the particular dry process involving the vapor gas is carried out on the wafer surface. In a preferred embodiment the metering device is an automotive fuel injector, sometimes referred to as a throttle body injector (TBI) that is energized by electrical pulses, each electrical pulse causing the TBI to inject a given predetermined amount into the vaporizer which heats the fluid, turning it into a vapor gas at pressure up to 760 Torr.
Abstract of the Disclosure A method and apparatus of dry processing a semiconductor wafer including processes of vacuum baking and dry silylation provides a gaseous atmosphere of pressure up to 760 Torr against the surface of the wafer, one or more of the constituents of the gas being obtained from a liquid fluid source of the constituent, including a metering device that controls flow of the liquid fluid from a remote reservoir and feeds it to a vaporizer that converts the fluid to a vapor gas at pressure up to 760 Torr and feeds the vapor gas at that pressure into a wafer processing chamber where the particular dry process involving the vapor gas is carried out on the wafer surface. In a preferred embodiment the metering device is an automotive fuel injector, sometimes referred to as a throttle body injector (TBI) that is energized by electrical pulses, each electrical pulse causing the TBI to inject a given predetermined amount into the vaporizer which heats the fluid, turning it into a vapor gas at pressure up to 760 Torr.
Description
1 APPARATUS FOR DRY PROCESSING A SEMICOMDUCTOR Whi: ER
2 Background of the Invention 3 This invention relates the method and means of dry 4 processing a semiconductor wafer and particularly for those dry processes that provide a gaseous atmosphere against the processe 6 surface of the wafer in which a gas consti~uent is obtained from 7 a liquid fluid source.
8 Fabrication of integrated circuits on a semiconductor wafer 9 substrate involves a number oP processes including photolithography processes that impose a pattern in photoresist 11 material on the substrate that varies in it's resistance to 12 chemical development or dry etching depending upon exposure to a 13 beam of radiation. The beam of radiation may be a light beam, a 14 electron beam (E-beam), X-rays or an ion beam. The development process leaves pattern~ of the re~ist mat~rial at the ~u~faco o~
16 the wafer upon which other processes such as deposition, impurit 17 implantation and other chemical processes are carried out.
18 The photolithographic process usually begins with 19 preparation of the wafer for coating That preparation may include cleaning, dehydration and priming. Heretofore, many of 21 these pre-coating steps have involved applying a liquid fluid to 22 the wafer surface.
23 Cleaning requires flooding the wafer with water and 24 scrubbing with a roller brush scrubber or high pressure spraying with water, followed by rinsing the water to insure complete 26 removal of fluids containing contaminates. Residues are removed 27 by hiqh temperature baking in combination with exposure to liqui 28 hexamethyldisilazane (HMDS) and sometimes in combination with vacuum and vapor~ of ~MDS, This i~ called priming. These and ~ 2 ~ 3~ ~
1 other conventional ~tep3 have been used to reduce de~ect density2 by removing sub-micron partlcles and preparlng and promoting 3 photore~ist adhesion.
4 Adhesion of the pho~oreslst to the semiconduator wafer surface i~ co~prornised by contaminates or water on thé surface.
- 6 ~Jafers that have been exposed to humidity or that have had dire~t contact with water during cleaning proce~se~ may have a mono 8 layer of water attached to the surface by Vanderwal force~.
9 Failure to remove the water may re~ult in compromi~ing the bond 0 between the photoresist and the semiconductor ~urface resulting Il in high defect density. Photoresist has conventionally been 12 accomplished by chemically chang~ng the ~urface of the wafer by~
13 1. Removing the mono-layer of water with heat ~360C).
14 2. Silylating the semiconductor surface by exposure to organometallic reagents like HMD5.
lG Method~ of exposing the surface of an uncoated ~emiconductox 17 wafer to a primary silylating xeagent like HMDS inslude the 18 ollowings 19 (a) Flooding the wafer surface w~th liquid reagent. For example, HtlDS is puddled on the sur~ace to prime it.
21 ~b) Expose the wafer sur.~ce to vapors of the reagent and 22 nitrogen at atmospheric pre~sure ~760 Torr) and elevated 23 wafer temperature. An example of thls technique i~
24 de~cribed in U.S. Patent 4,556,785, entitled n Semicondu~tor Wafer Baking Apparatus", issued 12/03/85 to J. Blechschmi~
26 R. Do Coyne, D. ralmer and JO A. Ptatt.
28 . . .
6~7~4,__, 1 ¦ (c) Expose the wafer surface to vapors o the reagent in n 2 sealed container (vapor pxessure 1 to 16 Torr) and heat the 3 wafex. For example, the system i~ loaded in an oven and the 4 liquid reagent is heated to raise its vapor pre~sure.
At this t~me, the above methods are performed by equipme~t available from several sources.
7 The coating proce~ in present use is a wet proces~ and i8 8 suitable for use in conjunction with the method and apparatus of ~ the present invention. Coatlng materials are po~itive or negative resist. Some of these are developed wet and some are Il developed by heat or by auto-evaporation of exposed resist. Wet 12 development of both positive and negative resint i8 the mo~t 13 widely used. Self-development resists have had limited use due 14 to their inability to stand up to dry process demands of advanced ~ manufacturing methods such as reactive ion etching (RIE).
lG Developing of positive or negative re~i~t is conventionally 17 a wet process and involves the u~e o spinner~ for the spray 18 application of liquid reagents formulated to remove the re8i8t 19 selectively and so tran~fer the radiation image through the resist to the semiconductor wafer surface to be proces~ed 21 ~etched~. Perfect~on of these wet develop techniques have for 22 the mo~t part addres~ed the problem ~f developing uniformity and a3 do little or nothing to reduce particles produced during the wet 24 developing, wet etching proce3ses.
~5 Etching must be clean reliable and accurate to be ~uitable 2~ for VSLI line widths. That need ha~ motivated development of 27 techniques of processing semiconductor wafers in a vacuum using 28 reactive ion etching ~RI~). The method and apparatus of the _ 4 -~ 79~__ 1 ¦pre~ent invention teaches developing and etching o~ both Rositive 2 ¦and negative photoresi~ts in an RIE proce3s atex exposure.
3 ¦ Self developing photoresist~ and the techniqueæ for using 4 ¦them will become more useful when apparatu3 according to the 5 ¦present invention i5 available to maintain wafer to wafer 6 ¦consi~tency. The present invention teache~ a method and 7 ¦apparatus for ~tabilizing the photore~lst ~nd m~klng tho r~sl~t 8 ¦more resistant to damage, particularly when the image is 9 ¦transferred to the semiconductor surface during ~IE.
8 Fabrication of integrated circuits on a semiconductor wafer 9 substrate involves a number oP processes including photolithography processes that impose a pattern in photoresist 11 material on the substrate that varies in it's resistance to 12 chemical development or dry etching depending upon exposure to a 13 beam of radiation. The beam of radiation may be a light beam, a 14 electron beam (E-beam), X-rays or an ion beam. The development process leaves pattern~ of the re~ist mat~rial at the ~u~faco o~
16 the wafer upon which other processes such as deposition, impurit 17 implantation and other chemical processes are carried out.
18 The photolithographic process usually begins with 19 preparation of the wafer for coating That preparation may include cleaning, dehydration and priming. Heretofore, many of 21 these pre-coating steps have involved applying a liquid fluid to 22 the wafer surface.
23 Cleaning requires flooding the wafer with water and 24 scrubbing with a roller brush scrubber or high pressure spraying with water, followed by rinsing the water to insure complete 26 removal of fluids containing contaminates. Residues are removed 27 by hiqh temperature baking in combination with exposure to liqui 28 hexamethyldisilazane (HMDS) and sometimes in combination with vacuum and vapor~ of ~MDS, This i~ called priming. These and ~ 2 ~ 3~ ~
1 other conventional ~tep3 have been used to reduce de~ect density2 by removing sub-micron partlcles and preparlng and promoting 3 photore~ist adhesion.
4 Adhesion of the pho~oreslst to the semiconduator wafer surface i~ co~prornised by contaminates or water on thé surface.
- 6 ~Jafers that have been exposed to humidity or that have had dire~t contact with water during cleaning proce~se~ may have a mono 8 layer of water attached to the surface by Vanderwal force~.
9 Failure to remove the water may re~ult in compromi~ing the bond 0 between the photoresist and the semiconductor ~urface resulting Il in high defect density. Photoresist has conventionally been 12 accomplished by chemically chang~ng the ~urface of the wafer by~
13 1. Removing the mono-layer of water with heat ~360C).
14 2. Silylating the semiconductor surface by exposure to organometallic reagents like HMD5.
lG Method~ of exposing the surface of an uncoated ~emiconductox 17 wafer to a primary silylating xeagent like HMDS inslude the 18 ollowings 19 (a) Flooding the wafer surface w~th liquid reagent. For example, HtlDS is puddled on the sur~ace to prime it.
21 ~b) Expose the wafer sur.~ce to vapors of the reagent and 22 nitrogen at atmospheric pre~sure ~760 Torr) and elevated 23 wafer temperature. An example of thls technique i~
24 de~cribed in U.S. Patent 4,556,785, entitled n Semicondu~tor Wafer Baking Apparatus", issued 12/03/85 to J. Blechschmi~
26 R. Do Coyne, D. ralmer and JO A. Ptatt.
28 . . .
6~7~4,__, 1 ¦ (c) Expose the wafer surface to vapors o the reagent in n 2 sealed container (vapor pxessure 1 to 16 Torr) and heat the 3 wafex. For example, the system i~ loaded in an oven and the 4 liquid reagent is heated to raise its vapor pre~sure.
At this t~me, the above methods are performed by equipme~t available from several sources.
7 The coating proce~ in present use is a wet proces~ and i8 8 suitable for use in conjunction with the method and apparatus of ~ the present invention. Coatlng materials are po~itive or negative resist. Some of these are developed wet and some are Il developed by heat or by auto-evaporation of exposed resist. Wet 12 development of both positive and negative resint i8 the mo~t 13 widely used. Self-development resists have had limited use due 14 to their inability to stand up to dry process demands of advanced ~ manufacturing methods such as reactive ion etching (RIE).
lG Developing of positive or negative re~i~t is conventionally 17 a wet process and involves the u~e o spinner~ for the spray 18 application of liquid reagents formulated to remove the re8i8t 19 selectively and so tran~fer the radiation image through the resist to the semiconductor wafer surface to be proces~ed 21 ~etched~. Perfect~on of these wet develop techniques have for 22 the mo~t part addres~ed the problem ~f developing uniformity and a3 do little or nothing to reduce particles produced during the wet 24 developing, wet etching proce3ses.
~5 Etching must be clean reliable and accurate to be ~uitable 2~ for VSLI line widths. That need ha~ motivated development of 27 techniques of processing semiconductor wafers in a vacuum using 28 reactive ion etching ~RI~). The method and apparatus of the _ 4 -~ 79~__ 1 ¦pre~ent invention teaches developing and etching o~ both Rositive 2 ¦and negative photoresi~ts in an RIE proce3s atex exposure.
3 ¦ Self developing photoresist~ and the techniqueæ for using 4 ¦them will become more useful when apparatu3 according to the 5 ¦present invention i5 available to maintain wafer to wafer 6 ¦consi~tency. The present invention teache~ a method and 7 ¦apparatus for ~tabilizing the photore~lst ~nd m~klng tho r~sl~t 8 ¦more resistant to damage, particularly when the image is 9 ¦transferred to the semiconductor surface during ~IE.
10 Iwet Process Photolithogra~hy I
11 ~8 mentioned above, many of the processing steps involve ~2 applying a liquid fluid to the wafer fiurface. For example, the 13 wet procesfi for carrying out photolithography require~ flooding, 14 spraying or immersing the wafer in a liquid fluid chemical under controlled conditions calculated to accompllsh the process. That lG process i~ terminated by removing the liquid from the wafer and 17 is followed by rlnsin~ the wafer with another liqu~d to ensure 18 complete removal of the first liquid. There must not be any 19 residue of the process liquids left on the wafer and part~cular ao han~ling techniques must be followed to ensure this. An 21 advantage of dry proce~Qing where ~ gas fluid 1Y used rathex than 22 a liquid fluid avoids these problems of residue and replaces many 23 ~tep~ with one.
2~ Dry Process Photolithogra~
A dry photolithography p~ocess usually begin~ with txeating 2G the surface of a silicon wafer. Then the wafer ~urfAce i~ coated 27 with a photore~ist by a wet proces~, because that is the best 28 known way of adding the photore~i~t. Next the photore~i~t l~
' _ 5 _ ~ 286~4--1 expo~ed to radiation through a mask pattern and then steps are 2 taken to develop the pattern including removing the unexposed 3 parts of the etchable sub~trate in which the photoinitiator i~
4 not exposed. ~s mentioned above, perfection o~ thl~ ~ry photolithography proce~s has led to a technique o prlming the 6 wafer before the photoresist is applied to it. The efect of the 7 priming step is to ensure adherence of the photore~i~t to the 8 .silicon so tha~ it will not separate during the following 9 processing. From such separation, small piece~ of exposed ~imaged) resist are lo~t during ~he development, degrading the 11 process .
I2 Priming Processes 13 One priming proce~s, in effect, is a ~ilylation proce~s that 14 uses ~ilane vapor. The silane vapor can be obtained from vaporizing an organosilicone compound such as liquld silane sold la under the trade name H~IDS. One æource of such H~DS i3 mar~eted 17 un~er the trademark HMDS PLUS and i8 a hexamethyldisilazane.
18 Another suitable from of HMDS is glycidoxypropyltrlmethoxysllane I9 which has.been produced by IBM.
Photoresist Silylation To Resist Etchin~
21 Another silylation process, in effect, coat~ the radiation 22 exposed (imaged) photoresist with organometallic polymer8 whlch 23 are particularly resistant to plasma etching. As a con~equence, 1 24 the subsequent dry etching process can then be accomplished by reactive ion etching (RIE), applying a plasma such a~ oxygen or 2¢ halocarbon plasma or anothe.r RIE gas ha~ little effect on the 27 organometallic silylated resist which forms only where the 28 photoresist has been exposed to radiation, whereas RIE remove~
. .' ~ 367~
1 ¦~he organometallic monomer~ that remain unbonded in the re~ist 2 ¦where it has not been exposed to radiations and, of course, 3 removes the un~ilylated re~ist layer below lt.
4 Such a process for H~S silylation of the surRace of the photoresist substrate for preparing a negative relief lmage is 6 described in US Patent tlo. 4,551,41~ whlch is~ued November 5t 7 1985 to Hult et al and i8 entitled Process for Preparlng Negative ~ Relief Images With Cationic Photo Polymerizatlon. That patent 9 descrlbes the process of HMDS silylation a~ including step3 of.
coating a silicon substrate with an etcha~le substxate such as a 1 polymeric layer containing at least at its surface a cationic 12 photoinitiator. The photoinitiator is exposed to radiation 13 through a mask (a pattern or radiat~on) and then contacted with 14 the HMDS at vapor pressure between 6 and 500 Torr. The HMDS 1~
suscepti~le to cationic polymerization and so form3 a polymer on lG the polymeric layer where the cationic photoinitiator has been 17 exposed to radiation. This polymerized monomer formed from the 18 llM~S ranges in thickness from a few angstrom units to several .
19 microns and the polymerized products contained ~n lt include organometallic polymer~ which are particularly resistant to 21 pla~ma etching. In this way, a thin layer i~ formed on the 22 photoresist sub~trate that is highly resistant to plasma etching 23 where the photore~ist surface ha~ been exposed to radia~ion.
2~ It is an object of the pre6ent invention to p~ovlde a metho~
and means of performing all of the above mentloned sllylatlon 2G step~ to increase the resistance of the radifltion exposed 27 photoresist to plasma etching and in addition perform the steps 28 of priming and several steps of baking in a predetermined _ 7 - ' ~ i794--1 sequence on a given wafer without removing the wafex from the 2 apparatus and in which all o the processes are dxy processe~.
3 andling Reagent~
4 HMDS and similar organosillcone compounds are highly volatile, flammable liquids. Heretofore, processes like priming 6 have been carried out with HMDS at approximately 6 Torr and the 7 results have been reasonably sati~factory. Priming has not been 8 carried out at pressure greater than 6 Torr even though there 1B
9 evidence that the priming process would be carried out faster and perhaps more effectively at a higher pre~ure (higher 11 concentration of HMD5 gas). Similarly, silylation with 12 organo~ilicone compounds such as ~MDS in the vapor phase have ~3 been carried out at 6 Torr although that process ls preferable 14 carried out at at least 200 Torr HMDS vapor prQs~ure which 16 requires heating the HMDS liquid to over 70C in order ~o produce lG the 200 Torr vapor pressure. At that temperature the HMDS will 17 flaqh into combustion in the presence of oxygen and so is a 18 hazard.
19 It i8 another and further object of the present invention to provide a method and meanC of producing H~IDS gas and vapor at 21 pressurec on the order of 2no Torr while avoiding the hazardou~
22 condition~ mentioned above and encountered in experimental work a3 done in the past.
~5 , . ..
28 ..
` ~'~8~7~ _ 1 Summary of the Invention 2 It 1~ a further object of the presPnt invention to provide a 3 method and means of converting a liquid reagent into a gas ox 4 vapor in a proce~sing chamber at a pres~ure sub~tAntlally gr~t0r than the vapor pressure of the liquid at room temperature ~nd B atmospheric pressure (21C and 760 mm Hg~ ~180 called 3tand~rd 7 temperature and pre~sure or STP.
8 It i~ another object to provide apparatus ~or converting a 9 liquid reagent into a vapor ga~ at controlled temperature and pressure above STP in minute discreet quantitie~ of the liquid, .
11 in sequence, as controlled by electrical impulse~, whereby a 12 count of the electrical impulses represent~ a given predetermined 13 quantity of the material.
14 It is another object to provide a method and means of producing and maintaining the vapor pressure of the reagent in lG the proce~ing chamber at a predeterm~ned (deslred or set) 17 pre~sure by controlling ~aid eleatrical lmpul~e~ ~o that the chamber pressure reaches the de~ired pressure without over~hoot 19 or oscillation around the desired level.
Embodiments of the present invention incorporate a method 21 and apparatus of dry processing a semiconductor wafer including 22 proce~ses of vacuum baking and dry silylation in which a gas~ous 23 reagent atmosphere (such as }IMDS) of pres~ure up to 760 ~orr i~
24 provided against the surface of the wafer, the reagent being obtained from a liquid fluid source and the gaqeous reagent 2G atmo~phere being isolated from the liquid fluid reagent ~our~e.
27 The apparatus includes a metering device that controls flow of 28 the liqu~d fluid reagent from a remote re~ervoir and Eeed~ it to _ g .
~ 7~3a~
1 a vaporizer that converts it to a vapor gas at pressure up to 760 2 Torr. That gas i9 fed to the wafer proces~ing chamber where the 3 particular dry process involving the Reagent gas is ¢arried out on the wafer surface.
In a preferred embodiment the metering device i~ an 6 automotive fuel in~ector, sometimes referred to as a throttla 7 body injec~or (TBI) that i~ energized by electrical pulse~, e~ch 8 electrical pulse causing the TBI to ln~ect a given predeterm1ned 9 amount of the reagent into the vaporizer which heats the fluid, O turning it into a vapor gas at pre~sure up to 760 Torr.
Il In a preferred embodiment, the electrical pul~e rate 18 12 varied as a function of proce~sing chamber pre~ure. Al~o, 13 processing chamber pressure i8 maintained at a given 14 predetermined value (desired or set pressure)s and for that purpose, a feedback signal is produced that represents the lG result~ of a comparison of chamber pressure with deslrea chamber ~7 pressure and the feedback signal controls the pulse rate. More ~8 particularly, this is a null type feedback control system and ~8 19 damped so that chamber pres~ure does not oscillate arou~d the desire~ pressure. The pulse rate reduces gradually as chamber 21 pressure approaches the ~esired or set pressure and when this 22 feedback system operates ideally, the damping is critical.
23 ~pplications of the present invention described herein 24 include, the processing step that uses H~1DS to prime the ~urface of the 3ilicon ~ubstrate before coating the ~urface with a layer 2G of photore~i~t material, referred to herein as ~Primen. After 27 Prime, the surface is coated with a thin layer ~about 0.5 to 2.0 28 microns thickl of photoresi~t such as a polymeric layer , - 10' -. '-.
~ W67'3~ _ 1 containing a cationic photoini~iater ~uch as ~old under ~he 2 trademark "l40" by Shipley Company. This i~ referred to herein 3 a~ "Coat". Then, the substrate is baked at a~out 50C ~or about 4 a minute until the photoresist layer hardens and volatile solvents are driven off. The preferred technlque in the present 6 invention is to include the photoinitiator in the re~ist layer.
7 During the baking process, the photoinitiator i8 incorporated 8 into the body of the photore~ist polymer layer. Th1s baking 9 process i8 referred to herein as "Softbaken.
0 The next step is exposure to radiation through a mask to create an exposed pa~tern on the photoresist layer, the expo~ure 12 preferably being done using ultraviolet ~UV) radiation at one of 13 the principal spectral lines of a mercury arc (577, 546, 435, or 14 365nm wavelength~. This step in pro~es~ing is re~errèd to hereln 16 as "~xpocuren. Next, follows the silylation proce~ that induces lG the formation of organometallic polymers at the ~urface o the 17 photoresist where the photoresist has been exposed to the UV
l8 radiation. This processing step is referred to herein aa 19 ~Silylationn. Following that, or simultaneou~ w~th the ao Silylation, a hard baking process ensues at controlled 21 temperature for a predetermined duration. This step i~ referred ~2 to herein a~ "Hardbake". Finally, the etching process i~
23 performed and in the preferred embodiment herein it i8 an oxygen 24 plasma etching process that is a reactive ion etching (RIE) process and is preferred to other RIE proce~se~ Thls etching 2G proces8 is referred to herein generally a~ "RIEn.
27 According to the present invention di~cxeet predetermined 28 quantitie~ of a liquid, herein refçrred to as xeagent, at ~ .
~ 3~ `-1 ¦controlled initial temperature and pressure are convertecl into a 2 vapor gas at a substankially greater pressure and temperature 3 than the vapor pressure of the liquid at ~tandard temperature 4 and pressure (STP). In particular embodiments of the pre~ent invention this feature i8 advantageously used to convert ~
6 flammable organosilicone reagent liquid, like HMDS, at STP in~o 7 a vapor gas at far greater pres~ure than the vapor pressure of the reagent liquid at STP, because it avoids heating the ~ource of reagent liquid to provide the higher pres~ure of vapor at ths 0 liquid vapor interface thereof and, in~tead, permit~ ra~s~ng ~1 temperature and pressure of only ~mall successive quantlties of 12 the flammable liquid reagent.
13 In a particular embodiment of the present lnvention 14 described herein, the reagent is HMDS and the converter include~
a metering device.having a liquid fluid input from an NMD~ liquld IG reæervoir and a vapor output that flows into an evaporator and 17 filter that convert ~ub~tantially all of the ~MDS vapor in~o a 18 gas and heats the gas. The metering device is an automotlve throttle body injector ~TBI) that is actuated by electrical .
pulses causing the TBI to inject a given prsdetermined quantity 21 of the liquid fed to it each tlme it i8 actuated. The evaporator 22 and filter open into the wafer procesRing chamber on which a 23 suitable back pressure is maintained, ~about 200 Torr) for 24 carrying out the ~IMDS ~ilylation process. The metering de~ic~
(T8I) isolates the high température H~IDS gas from the ~MD8 llquid 2G source at STP and draws only as much of ~t from the ~our~e as 1 27 needed to charge the wafer processing chamber. Clearly the 28 source can be located remote from the metering device and the , l 79~
l processing chamber and the source can be maintained at all times at a safe low temperature.
The same apparatus and method can be used to carry out the Prime process more effectively than in the past, because it can be carried out a higher pressure and temperature of the reagent vapor.
In one aspect the present invention provides an apparatus for dry processing a semiconductor wafer in the manufacture of circuit patterns thereon comprising, a vacuum chamber for containing said semiconductor wafer to be - processed, an opening into said chamber for the flow of a processing fluid in gaseous form into said chamber, a source of said processing fluid in liquid form, between said source of processing fluid in liquid form and said chamber opening, a fluid meter having a liquid fluid input and an output into a relatively low pressure evaporation chamber that connects to said opening into said processing chamber for converting said metered fluid into metered gas fluid, said metered gas - fluid being isolated from said liquid fluid by said fluid meter and means for energizing said fluid meter, whereby said fluid meter passes liquid fluid from said source in metered quantities into said evaporation chamber as a mixture of gas and vapor and said mixture is substantially all converted into gas that flows through said opening into said processing chamber.
:' 8~7~
1 Other objects and features of ~he present invention will be apparent from the following detailed description of the several features of the invention mentioned above taking in conjunction with the drawings in which:
Description of the Drawings Figure 1 is a partially schematic electric and fluid flow diagram and partially structural diagram shown in cross section of a reagent flow system and controls using an automotive throttle body injector (TBI) for metering HMDS
flow to a dry processing vacuum rnodule chamber, so that the source of the reagent may be safely isolated from the system;
Figure 2 is a plot of processing chamber vapor pressure versus time for the system shown in Figure 1 wherein the pulse rate of control signals to the TBI driver circuit is variable and shows the advantage of variable pulse rate according to the present invention over fixed pulse rate;
Figures:3a, 3b, and 3c are diagrams representing part of a wafer in cross section illustrating the process of HMDS silylation and following that the effects of the hard baking and RIE development processes. These drawings are diagrams and they are offered as an aid to ~nderstanding the processes; and - 13a -. .~
~ 67~ -1 ¦ Figure 4 is a plot of HMDS vapor pressure versu~ IIMDS liquld 2 ¦~emperature.
3 I Embodiment of the Invention ~ , 4 ¦ Flgure l i3 a diagram showing the ~igniflcant part~ of a 5 ¦vacuum processing module for dry vacuum ~urface treatment of a 6 ~emiconductor wafer for performing ~ome of the processes involved 7 in forming integrated circuit structures on the wafer surface.
8 The procesRes tha~ the module along with its controls and fluid g feed can perform are the processes: Prime, Softbake, Hardbake a~d Silylation, in whatever order desired, rapidly and under 1~ ultra-clean conditions.
12 While the module shown in Figure l doe~ not have the 13 capacity of use of coating the primed surface of the wafer wi~h a 14 suitable photoresist film and ~t has no provi~lon~ for 1~ irradiating the photoreRist with radiation through a mask to 1¢ define a pattern (an electric circuit pattern) in the re~ist and 17 it do~ not have use to etch the photoresi3t to form the pattern, 1~ it i5 suggested that those capacities can be added to thi~ ~odul~
19 by modification~ so that all the procè~e~ from priming through etching could be accomplished on the wafer without removing lt 21 from such a modified module. This module structure i8 shown a~
22 an example of what can be done toward providing aquipment that 23 can operate to perform the full serie~ of proce~ses from priming 24 through etching on a semiconductor wafer and partlcularly to perform all of the processes dry.
2G In Figure 1, the module l i~ ~hown in cutaway view to 27 reveal the principal parts includes a wafer processing vacuum 28 ¦ ch er 2 containing semiconductor wafer 3 beld f1at (by me~n~
3L~6~7'r~
1 not shown) exposing the top surface 3a to be processed. The 2 processing chamber part of module 1 and other parts, for the most 3 part, are figures o~ revolution and ~o are ~hown fully by the 4 cutaway view in F~gure 1. The chamber is evacuated by a vacuum source (not shown) and for this purpose tube 4 leads from the 6 periphery of the chamber to vacuum control valve 5 that connect~
7 to the vacuum source. Gas input to th~ chamber 18 through 8 central port 6 that lead~ from a filter ev~porator 7 formed ln 9 cavity 8, that includes a porou~ cup-shaped filter 9 which may be a pebble bed filter of 0.01 micron porosity. These filter 1l substantially fills cavity 8 with some clearance around the 12 out3ide of the filter. A pebble bed ~ilter ~uitable for this ~3 embodiment has 0.01 mlcron pores l~ made of O.S mlcron bead0 and 14 is approximately a half inch in diameter. Such a filter i8 16 available from Mott Company and is efective to aid evaporation lG of vapor lowing through it to the proce~sing chamber.
~7 The purpose of filter evaporator 7 is to convert any ~por 18 injected into gasO In this proces~, the filter 9 hold~ any vapor 1~ flowing into lt from trap 11 and spread~ the vapor throughout the porous structure of the filter 80 that it evaporates.
21 Evaporation i~ accelerated by heating the filter, its cavlty and 22 the trap ~avi~y. Trap ll ~ formed by cavity 12 ~nd the filter 23 cavity 8 and the trap cavity 12 are preferably arranged upright 24 as shown and the opening at 13 between the two cavities i8 above the floor 14 of the trap cavity and 80 a liquid trap i~ formed.
2G Heating to accelerate evaporation may be done wlth heater~
28 ~urrounding or within the filter cavity and trap cavity, and/or - 15 - ' ~L~86~
1 by heat flow through the body of the module 1 from heaters 45 a~d 2 46 in the walls of processing chamber 2.
3 Above the trap cavity 12 positioned to ~nject vapor and ga~
4 into it is metering device 20, This device receives a liquid reagent to be gasified, such as liquid HMDS, from liquld flow 6 line 31 from a container 32 of the liquid reagent at a remote 7 location where the reagent liquid is contained at a safe 8 temperature and pressure, such as standard temperature and 9 pressure (STP) and is surrounded by such physical barriers as required by safety standards for storing volatile flammable 1~ liquids~
12 A valve 33 in line 31 controls the liquid reagent in the 13 line to metering device 20. The liquid reagent from line 31 ~4 flows into the metering device cavlty 21 ln module 1 around device 20 and through a filter 23 in the metering device lnto the lG device body.
17 Metering device 20 may be constructed substantially the ~ame 18 as an automot~ve throttle body injector (T~I) such a~ uqed in 19 many General Motors automobiles. As such, it ~ 8 controlled by electrical pul~es from an electric power supply and each 21 electrical pulse causes the injector to inject a given 22 predetermined quantity of the liquid fluid fed to it. Inasmuch 23 as a reagent such as H~IDS, has propertie~ that are similar to 2~ gasoline with respect to density, viscosity, flammabillty and even non-compatibility to synthetic3, the TBI pump can be u3ed 2G for injecting any of a number of silylating reagents lnto module 27 1 ~ubstantially as it is used in a General ~lotors ~utomobile.
~ven the operating range of the TBI is suitable for use as I 1~ 8~
1 ¦described hereln. For example a single impulse injection frc)m a 2 ¦TBI ~s completed in 4 milliseconds and in~ect~ (meters~ a volume 3 of about .01 milliliters and this can be repeated up to 250 time~
4 per ~econd to vary the flow rate.
The TBI (metering device) i8 seated in it~ cavity 21 and 6 sealed at the top and bottom. For thi~ purpo~e a top 0 r~ng seAl 7 24 and a bottom 0 ring seal 25 are provided. Thus, the annular 8 cavity around the outside of the T~I and cavity 21 between the 9 top and bottom 0 ring seals defines a closed, sealed ~pac~ for 0 containing a small portion of the liquid reagent 80 that it flowa on demand through filter 23 and into the TBI.
~2 T~I 20 is actuated by electrical pul~e~ provided to it at 13 terminal~ 26 and 27 from TBI driver circuits 28 energized by TnI
14 power 5upply 29. With each ~lectri~al impul~s to the3e termlnals, a plunger within the injector cycles and an ~mpul~e of lG reagent HMDS i8 injected fr~m the bottom of the TBI at point 30 ~7 into the trap cavity 12. Thu~, liquid reagent i8 fed into TBI 20 18 at STP and the TBI meters reagent in discreet impulses a~ a 19 mixture of gas and vapor into vacuum (the pressure in cavlty 12) that i~ maintained by the vacuum souree depending upon the 2t operation of vacuum source valve 5. The pre~sure in cavity 12 ~3 22 substantially below atmospheric and only slightly greater than a3 the pressure maintained ~n proces~ing ohamber 2.
2~ The impulse of reagent gas and vapor in~ected at 30 flows through trap wherein some of the vapor is gasifled and thl~
2¢ predominantly gaseous mixture o~ ga0 and vapor flows through 13 27 ~nto filter evaporator 6 where it encounters the heated pebbl~
28 bed filter 9 and any remaining vapor i9 gasified. As a re~uIt I ~28~
1 ¦the flu~ going into chamber 2 fill~ the chamber with a pure 2 ¦gaseous reagent environment again~t the top ~urface 3a of wafer 3 13- The reagent is prevented from impinging directly on wàfer 3 4 ~by shield 10 which cause~ the vapor ga~ entering 6 to #pread 5 ¦throughout pro,ces~ing chamber 2.
6 ¦ The pressure in chamber 2 is maintained by operations of 7 ¦valve 5. For this purpose, pressure in chamber 2 i8 detected by 8 ¦transducer 41 which converts that pressure slgnal into an ~ ¦electrical signal that is fed to vacuum controller and pressure 10 ¦readout unit 42. Unit 42 contains circuit~ that compare the ] ¦pressure signal from transducer 41 with a signal representative 12 of desired or set pressure that may be stored in central 13 proces~or ~nit (CPU) 43 or may be manually input. The output of ~ unit 42 is the feedback signal (FB) in line 42a representative ~f 16 the pressure differential that the sy6tem must make up by feeding lG HMDS vapor to the chamber.
17 The FB ~ignal is fed to TBI voltage/frequency modulator unit 18 4~ which generates suitable control pulses to TBI driver circuit~
2~ Dry Process Photolithogra~
A dry photolithography p~ocess usually begin~ with txeating 2G the surface of a silicon wafer. Then the wafer ~urfAce i~ coated 27 with a photore~ist by a wet proces~, because that is the best 28 known way of adding the photore~i~t. Next the photore~i~t l~
' _ 5 _ ~ 286~4--1 expo~ed to radiation through a mask pattern and then steps are 2 taken to develop the pattern including removing the unexposed 3 parts of the etchable sub~trate in which the photoinitiator i~
4 not exposed. ~s mentioned above, perfection o~ thl~ ~ry photolithography proce~s has led to a technique o prlming the 6 wafer before the photoresist is applied to it. The efect of the 7 priming step is to ensure adherence of the photore~i~t to the 8 .silicon so tha~ it will not separate during the following 9 processing. From such separation, small piece~ of exposed ~imaged) resist are lo~t during ~he development, degrading the 11 process .
I2 Priming Processes 13 One priming proce~s, in effect, is a ~ilylation proce~s that 14 uses ~ilane vapor. The silane vapor can be obtained from vaporizing an organosilicone compound such as liquld silane sold la under the trade name H~IDS. One æource of such H~DS i3 mar~eted 17 un~er the trademark HMDS PLUS and i8 a hexamethyldisilazane.
18 Another suitable from of HMDS is glycidoxypropyltrlmethoxysllane I9 which has.been produced by IBM.
Photoresist Silylation To Resist Etchin~
21 Another silylation process, in effect, coat~ the radiation 22 exposed (imaged) photoresist with organometallic polymer8 whlch 23 are particularly resistant to plasma etching. As a con~equence, 1 24 the subsequent dry etching process can then be accomplished by reactive ion etching (RIE), applying a plasma such a~ oxygen or 2¢ halocarbon plasma or anothe.r RIE gas ha~ little effect on the 27 organometallic silylated resist which forms only where the 28 photoresist has been exposed to radiation, whereas RIE remove~
. .' ~ 367~
1 ¦~he organometallic monomer~ that remain unbonded in the re~ist 2 ¦where it has not been exposed to radiations and, of course, 3 removes the un~ilylated re~ist layer below lt.
4 Such a process for H~S silylation of the surRace of the photoresist substrate for preparing a negative relief lmage is 6 described in US Patent tlo. 4,551,41~ whlch is~ued November 5t 7 1985 to Hult et al and i8 entitled Process for Preparlng Negative ~ Relief Images With Cationic Photo Polymerizatlon. That patent 9 descrlbes the process of HMDS silylation a~ including step3 of.
coating a silicon substrate with an etcha~le substxate such as a 1 polymeric layer containing at least at its surface a cationic 12 photoinitiator. The photoinitiator is exposed to radiation 13 through a mask (a pattern or radiat~on) and then contacted with 14 the HMDS at vapor pressure between 6 and 500 Torr. The HMDS 1~
suscepti~le to cationic polymerization and so form3 a polymer on lG the polymeric layer where the cationic photoinitiator has been 17 exposed to radiation. This polymerized monomer formed from the 18 llM~S ranges in thickness from a few angstrom units to several .
19 microns and the polymerized products contained ~n lt include organometallic polymer~ which are particularly resistant to 21 pla~ma etching. In this way, a thin layer i~ formed on the 22 photoresist sub~trate that is highly resistant to plasma etching 23 where the photore~ist surface ha~ been exposed to radia~ion.
2~ It is an object of the pre6ent invention to p~ovlde a metho~
and means of performing all of the above mentloned sllylatlon 2G step~ to increase the resistance of the radifltion exposed 27 photoresist to plasma etching and in addition perform the steps 28 of priming and several steps of baking in a predetermined _ 7 - ' ~ i794--1 sequence on a given wafer without removing the wafex from the 2 apparatus and in which all o the processes are dxy processe~.
3 andling Reagent~
4 HMDS and similar organosillcone compounds are highly volatile, flammable liquids. Heretofore, processes like priming 6 have been carried out with HMDS at approximately 6 Torr and the 7 results have been reasonably sati~factory. Priming has not been 8 carried out at pressure greater than 6 Torr even though there 1B
9 evidence that the priming process would be carried out faster and perhaps more effectively at a higher pre~ure (higher 11 concentration of HMD5 gas). Similarly, silylation with 12 organo~ilicone compounds such as ~MDS in the vapor phase have ~3 been carried out at 6 Torr although that process ls preferable 14 carried out at at least 200 Torr HMDS vapor prQs~ure which 16 requires heating the HMDS liquid to over 70C in order ~o produce lG the 200 Torr vapor pressure. At that temperature the HMDS will 17 flaqh into combustion in the presence of oxygen and so is a 18 hazard.
19 It i8 another and further object of the present invention to provide a method and meanC of producing H~IDS gas and vapor at 21 pressurec on the order of 2no Torr while avoiding the hazardou~
22 condition~ mentioned above and encountered in experimental work a3 done in the past.
~5 , . ..
28 ..
` ~'~8~7~ _ 1 Summary of the Invention 2 It 1~ a further object of the presPnt invention to provide a 3 method and means of converting a liquid reagent into a gas ox 4 vapor in a proce~sing chamber at a pres~ure sub~tAntlally gr~t0r than the vapor pressure of the liquid at room temperature ~nd B atmospheric pressure (21C and 760 mm Hg~ ~180 called 3tand~rd 7 temperature and pre~sure or STP.
8 It i~ another object to provide apparatus ~or converting a 9 liquid reagent into a vapor ga~ at controlled temperature and pressure above STP in minute discreet quantitie~ of the liquid, .
11 in sequence, as controlled by electrical impulse~, whereby a 12 count of the electrical impulses represent~ a given predetermined 13 quantity of the material.
14 It is another object to provide a method and means of producing and maintaining the vapor pressure of the reagent in lG the proce~ing chamber at a predeterm~ned (deslred or set) 17 pre~sure by controlling ~aid eleatrical lmpul~e~ ~o that the chamber pressure reaches the de~ired pressure without over~hoot 19 or oscillation around the desired level.
Embodiments of the present invention incorporate a method 21 and apparatus of dry processing a semiconductor wafer including 22 proce~ses of vacuum baking and dry silylation in which a gas~ous 23 reagent atmosphere (such as }IMDS) of pres~ure up to 760 ~orr i~
24 provided against the surface of the wafer, the reagent being obtained from a liquid fluid source and the gaqeous reagent 2G atmo~phere being isolated from the liquid fluid reagent ~our~e.
27 The apparatus includes a metering device that controls flow of 28 the liqu~d fluid reagent from a remote re~ervoir and Eeed~ it to _ g .
~ 7~3a~
1 a vaporizer that converts it to a vapor gas at pressure up to 760 2 Torr. That gas i9 fed to the wafer proces~ing chamber where the 3 particular dry process involving the Reagent gas is ¢arried out on the wafer surface.
In a preferred embodiment the metering device i~ an 6 automotive fuel in~ector, sometimes referred to as a throttla 7 body injec~or (TBI) that i~ energized by electrical pulse~, e~ch 8 electrical pulse causing the TBI to ln~ect a given predeterm1ned 9 amount of the reagent into the vaporizer which heats the fluid, O turning it into a vapor gas at pre~sure up to 760 Torr.
Il In a preferred embodiment, the electrical pul~e rate 18 12 varied as a function of proce~sing chamber pre~ure. Al~o, 13 processing chamber pressure i8 maintained at a given 14 predetermined value (desired or set pressure)s and for that purpose, a feedback signal is produced that represents the lG result~ of a comparison of chamber pressure with deslrea chamber ~7 pressure and the feedback signal controls the pulse rate. More ~8 particularly, this is a null type feedback control system and ~8 19 damped so that chamber pres~ure does not oscillate arou~d the desire~ pressure. The pulse rate reduces gradually as chamber 21 pressure approaches the ~esired or set pressure and when this 22 feedback system operates ideally, the damping is critical.
23 ~pplications of the present invention described herein 24 include, the processing step that uses H~1DS to prime the ~urface of the 3ilicon ~ubstrate before coating the ~urface with a layer 2G of photore~i~t material, referred to herein as ~Primen. After 27 Prime, the surface is coated with a thin layer ~about 0.5 to 2.0 28 microns thickl of photoresi~t such as a polymeric layer , - 10' -. '-.
~ W67'3~ _ 1 containing a cationic photoini~iater ~uch as ~old under ~he 2 trademark "l40" by Shipley Company. This i~ referred to herein 3 a~ "Coat". Then, the substrate is baked at a~out 50C ~or about 4 a minute until the photoresist layer hardens and volatile solvents are driven off. The preferred technlque in the present 6 invention is to include the photoinitiator in the re~ist layer.
7 During the baking process, the photoinitiator i8 incorporated 8 into the body of the photore~ist polymer layer. Th1s baking 9 process i8 referred to herein as "Softbaken.
0 The next step is exposure to radiation through a mask to create an exposed pa~tern on the photoresist layer, the expo~ure 12 preferably being done using ultraviolet ~UV) radiation at one of 13 the principal spectral lines of a mercury arc (577, 546, 435, or 14 365nm wavelength~. This step in pro~es~ing is re~errèd to hereln 16 as "~xpocuren. Next, follows the silylation proce~ that induces lG the formation of organometallic polymers at the ~urface o the 17 photoresist where the photoresist has been exposed to the UV
l8 radiation. This processing step is referred to herein aa 19 ~Silylationn. Following that, or simultaneou~ w~th the ao Silylation, a hard baking process ensues at controlled 21 temperature for a predetermined duration. This step i~ referred ~2 to herein a~ "Hardbake". Finally, the etching process i~
23 performed and in the preferred embodiment herein it i8 an oxygen 24 plasma etching process that is a reactive ion etching (RIE) process and is preferred to other RIE proce~se~ Thls etching 2G proces8 is referred to herein generally a~ "RIEn.
27 According to the present invention di~cxeet predetermined 28 quantitie~ of a liquid, herein refçrred to as xeagent, at ~ .
~ 3~ `-1 ¦controlled initial temperature and pressure are convertecl into a 2 vapor gas at a substankially greater pressure and temperature 3 than the vapor pressure of the liquid at ~tandard temperature 4 and pressure (STP). In particular embodiments of the pre~ent invention this feature i8 advantageously used to convert ~
6 flammable organosilicone reagent liquid, like HMDS, at STP in~o 7 a vapor gas at far greater pres~ure than the vapor pressure of the reagent liquid at STP, because it avoids heating the ~ource of reagent liquid to provide the higher pres~ure of vapor at ths 0 liquid vapor interface thereof and, in~tead, permit~ ra~s~ng ~1 temperature and pressure of only ~mall successive quantlties of 12 the flammable liquid reagent.
13 In a particular embodiment of the present lnvention 14 described herein, the reagent is HMDS and the converter include~
a metering device.having a liquid fluid input from an NMD~ liquld IG reæervoir and a vapor output that flows into an evaporator and 17 filter that convert ~ub~tantially all of the ~MDS vapor in~o a 18 gas and heats the gas. The metering device is an automotlve throttle body injector ~TBI) that is actuated by electrical .
pulses causing the TBI to inject a given prsdetermined quantity 21 of the liquid fed to it each tlme it i8 actuated. The evaporator 22 and filter open into the wafer procesRing chamber on which a 23 suitable back pressure is maintained, ~about 200 Torr) for 24 carrying out the ~IMDS ~ilylation process. The metering de~ic~
(T8I) isolates the high température H~IDS gas from the ~MD8 llquid 2G source at STP and draws only as much of ~t from the ~our~e as 1 27 needed to charge the wafer processing chamber. Clearly the 28 source can be located remote from the metering device and the , l 79~
l processing chamber and the source can be maintained at all times at a safe low temperature.
The same apparatus and method can be used to carry out the Prime process more effectively than in the past, because it can be carried out a higher pressure and temperature of the reagent vapor.
In one aspect the present invention provides an apparatus for dry processing a semiconductor wafer in the manufacture of circuit patterns thereon comprising, a vacuum chamber for containing said semiconductor wafer to be - processed, an opening into said chamber for the flow of a processing fluid in gaseous form into said chamber, a source of said processing fluid in liquid form, between said source of processing fluid in liquid form and said chamber opening, a fluid meter having a liquid fluid input and an output into a relatively low pressure evaporation chamber that connects to said opening into said processing chamber for converting said metered fluid into metered gas fluid, said metered gas - fluid being isolated from said liquid fluid by said fluid meter and means for energizing said fluid meter, whereby said fluid meter passes liquid fluid from said source in metered quantities into said evaporation chamber as a mixture of gas and vapor and said mixture is substantially all converted into gas that flows through said opening into said processing chamber.
:' 8~7~
1 Other objects and features of ~he present invention will be apparent from the following detailed description of the several features of the invention mentioned above taking in conjunction with the drawings in which:
Description of the Drawings Figure 1 is a partially schematic electric and fluid flow diagram and partially structural diagram shown in cross section of a reagent flow system and controls using an automotive throttle body injector (TBI) for metering HMDS
flow to a dry processing vacuum rnodule chamber, so that the source of the reagent may be safely isolated from the system;
Figure 2 is a plot of processing chamber vapor pressure versus time for the system shown in Figure 1 wherein the pulse rate of control signals to the TBI driver circuit is variable and shows the advantage of variable pulse rate according to the present invention over fixed pulse rate;
Figures:3a, 3b, and 3c are diagrams representing part of a wafer in cross section illustrating the process of HMDS silylation and following that the effects of the hard baking and RIE development processes. These drawings are diagrams and they are offered as an aid to ~nderstanding the processes; and - 13a -. .~
~ 67~ -1 ¦ Figure 4 is a plot of HMDS vapor pressure versu~ IIMDS liquld 2 ¦~emperature.
3 I Embodiment of the Invention ~ , 4 ¦ Flgure l i3 a diagram showing the ~igniflcant part~ of a 5 ¦vacuum processing module for dry vacuum ~urface treatment of a 6 ~emiconductor wafer for performing ~ome of the processes involved 7 in forming integrated circuit structures on the wafer surface.
8 The procesRes tha~ the module along with its controls and fluid g feed can perform are the processes: Prime, Softbake, Hardbake a~d Silylation, in whatever order desired, rapidly and under 1~ ultra-clean conditions.
12 While the module shown in Figure l doe~ not have the 13 capacity of use of coating the primed surface of the wafer wi~h a 14 suitable photoresist film and ~t has no provi~lon~ for 1~ irradiating the photoreRist with radiation through a mask to 1¢ define a pattern (an electric circuit pattern) in the re~ist and 17 it do~ not have use to etch the photoresi3t to form the pattern, 1~ it i5 suggested that those capacities can be added to thi~ ~odul~
19 by modification~ so that all the procè~e~ from priming through etching could be accomplished on the wafer without removing lt 21 from such a modified module. This module structure i8 shown a~
22 an example of what can be done toward providing aquipment that 23 can operate to perform the full serie~ of proce~ses from priming 24 through etching on a semiconductor wafer and partlcularly to perform all of the processes dry.
2G In Figure 1, the module l i~ ~hown in cutaway view to 27 reveal the principal parts includes a wafer processing vacuum 28 ¦ ch er 2 containing semiconductor wafer 3 beld f1at (by me~n~
3L~6~7'r~
1 not shown) exposing the top surface 3a to be processed. The 2 processing chamber part of module 1 and other parts, for the most 3 part, are figures o~ revolution and ~o are ~hown fully by the 4 cutaway view in F~gure 1. The chamber is evacuated by a vacuum source (not shown) and for this purpose tube 4 leads from the 6 periphery of the chamber to vacuum control valve 5 that connect~
7 to the vacuum source. Gas input to th~ chamber 18 through 8 central port 6 that lead~ from a filter ev~porator 7 formed ln 9 cavity 8, that includes a porou~ cup-shaped filter 9 which may be a pebble bed filter of 0.01 micron porosity. These filter 1l substantially fills cavity 8 with some clearance around the 12 out3ide of the filter. A pebble bed ~ilter ~uitable for this ~3 embodiment has 0.01 mlcron pores l~ made of O.S mlcron bead0 and 14 is approximately a half inch in diameter. Such a filter i8 16 available from Mott Company and is efective to aid evaporation lG of vapor lowing through it to the proce~sing chamber.
~7 The purpose of filter evaporator 7 is to convert any ~por 18 injected into gasO In this proces~, the filter 9 hold~ any vapor 1~ flowing into lt from trap 11 and spread~ the vapor throughout the porous structure of the filter 80 that it evaporates.
21 Evaporation i~ accelerated by heating the filter, its cavlty and 22 the trap ~avi~y. Trap ll ~ formed by cavity 12 ~nd the filter 23 cavity 8 and the trap cavity 12 are preferably arranged upright 24 as shown and the opening at 13 between the two cavities i8 above the floor 14 of the trap cavity and 80 a liquid trap i~ formed.
2G Heating to accelerate evaporation may be done wlth heater~
28 ~urrounding or within the filter cavity and trap cavity, and/or - 15 - ' ~L~86~
1 by heat flow through the body of the module 1 from heaters 45 a~d 2 46 in the walls of processing chamber 2.
3 Above the trap cavity 12 positioned to ~nject vapor and ga~
4 into it is metering device 20, This device receives a liquid reagent to be gasified, such as liquid HMDS, from liquld flow 6 line 31 from a container 32 of the liquid reagent at a remote 7 location where the reagent liquid is contained at a safe 8 temperature and pressure, such as standard temperature and 9 pressure (STP) and is surrounded by such physical barriers as required by safety standards for storing volatile flammable 1~ liquids~
12 A valve 33 in line 31 controls the liquid reagent in the 13 line to metering device 20. The liquid reagent from line 31 ~4 flows into the metering device cavlty 21 ln module 1 around device 20 and through a filter 23 in the metering device lnto the lG device body.
17 Metering device 20 may be constructed substantially the ~ame 18 as an automot~ve throttle body injector (T~I) such a~ uqed in 19 many General Motors automobiles. As such, it ~ 8 controlled by electrical pul~es from an electric power supply and each 21 electrical pulse causes the injector to inject a given 22 predetermined quantity of the liquid fluid fed to it. Inasmuch 23 as a reagent such as H~IDS, has propertie~ that are similar to 2~ gasoline with respect to density, viscosity, flammabillty and even non-compatibility to synthetic3, the TBI pump can be u3ed 2G for injecting any of a number of silylating reagents lnto module 27 1 ~ubstantially as it is used in a General ~lotors ~utomobile.
~ven the operating range of the TBI is suitable for use as I 1~ 8~
1 ¦described hereln. For example a single impulse injection frc)m a 2 ¦TBI ~s completed in 4 milliseconds and in~ect~ (meters~ a volume 3 of about .01 milliliters and this can be repeated up to 250 time~
4 per ~econd to vary the flow rate.
The TBI (metering device) i8 seated in it~ cavity 21 and 6 sealed at the top and bottom. For thi~ purpo~e a top 0 r~ng seAl 7 24 and a bottom 0 ring seal 25 are provided. Thus, the annular 8 cavity around the outside of the T~I and cavity 21 between the 9 top and bottom 0 ring seals defines a closed, sealed ~pac~ for 0 containing a small portion of the liquid reagent 80 that it flowa on demand through filter 23 and into the TBI.
~2 T~I 20 is actuated by electrical pul~e~ provided to it at 13 terminal~ 26 and 27 from TBI driver circuits 28 energized by TnI
14 power 5upply 29. With each ~lectri~al impul~s to the3e termlnals, a plunger within the injector cycles and an ~mpul~e of lG reagent HMDS i8 injected fr~m the bottom of the TBI at point 30 ~7 into the trap cavity 12. Thu~, liquid reagent i8 fed into TBI 20 18 at STP and the TBI meters reagent in discreet impulses a~ a 19 mixture of gas and vapor into vacuum (the pressure in cavlty 12) that i~ maintained by the vacuum souree depending upon the 2t operation of vacuum source valve 5. The pre~sure in cavity 12 ~3 22 substantially below atmospheric and only slightly greater than a3 the pressure maintained ~n proces~ing ohamber 2.
2~ The impulse of reagent gas and vapor in~ected at 30 flows through trap wherein some of the vapor is gasifled and thl~
2¢ predominantly gaseous mixture o~ ga0 and vapor flows through 13 27 ~nto filter evaporator 6 where it encounters the heated pebbl~
28 bed filter 9 and any remaining vapor i9 gasified. As a re~uIt I ~28~
1 ¦the flu~ going into chamber 2 fill~ the chamber with a pure 2 ¦gaseous reagent environment again~t the top ~urface 3a of wafer 3 13- The reagent is prevented from impinging directly on wàfer 3 4 ~by shield 10 which cause~ the vapor ga~ entering 6 to #pread 5 ¦throughout pro,ces~ing chamber 2.
6 ¦ The pressure in chamber 2 is maintained by operations of 7 ¦valve 5. For this purpose, pressure in chamber 2 i8 detected by 8 ¦transducer 41 which converts that pressure slgnal into an ~ ¦electrical signal that is fed to vacuum controller and pressure 10 ¦readout unit 42. Unit 42 contains circuit~ that compare the ] ¦pressure signal from transducer 41 with a signal representative 12 of desired or set pressure that may be stored in central 13 proces~or ~nit (CPU) 43 or may be manually input. The output of ~ unit 42 is the feedback signal (FB) in line 42a representative ~f 16 the pressure differential that the sy6tem must make up by feeding lG HMDS vapor to the chamber.
17 The FB ~ignal is fed to TBI voltage/frequency modulator unit 18 4~ which generates suitable control pulses to TBI driver circuit~
19 28 that controls actuation of TBI 20. Modulator unit 44 qenerates pulses of duty cycle and rate dictated by ~n output o~
21 CPU 43 and the FB signal~ Those pulses are fed via line 44a to 22 TBI driver c~rcuits 28. When the differential pres~ure is large, the pulse rate is high and when the diferential i3 small, the 24 pulse rate is low and may approach zero as the dlfferential approache~ zero. If chamber pressure exceeds the desired or set, 26 pressure, a signal is fed via modulator unit 44 to vacuum source 27 valve 5 causing the valve to open, relieving the chamber pre~sur~
28 ~nto the vacuum source. By thi6 null type feedback control - 18 - " .
. ,.
~ 7~
1 system, the desired or set chamber pressure is produced and 2 maintained.
3 Figure 2 is a plot of processinq chamber pres~ure versus 4 time showing the operation of the system of Figure l where pulse rate is varied or modulated bringing the chamber pre~sure to the 6 desired or set level without overshoot or oscillation around the 7 desired pressure. The plot also ~hows chamber pressure versu3 8 time for a similar system wherein pul~e rate is constant. A
~ system operating with constant pulse rate may reach the desired pressure level quicker, but is likely to overshoot and osc~llate 11 around the deslred pressure.
12 The temperature of the reagent gas in react~on chamber 2 l~
13 controlled by heating pads 45 and 46 that may be embedded in the 14 chamber walls and so the pressure and temperature of the reagent qas and the processing chamber is fully controlled and can ~e 1~ maintained at pressure up to 760 Torr or greater even while the 17 vapor pressure on the reagent tank 32 is no more than 6 Torr (or 18 the vapor pressure of the Reagent at STP). For that purpose, 19 temperature controller 47, controlled by CPU 43 is provided.
Clearly, T~I (metering device 20 isolates proces~ing chamber 21 2 from the tank 32 of liquid reagent. It should al~o be clear 22 that the line 31 carrying liquid Reagent from the tank to the 23 injector can be a very small diameter llne go that the total ~4 quantity of reagent contained ln that line and throughout the 25- module 1 i9 a very small quantity and 80 create5 minimal hazard.
2G The volume of liqu~d over a range of pres9ures ranging from 27 5 p9i to 20 psi that are in~ected by a TBI in a given number of 28 impulses does not change very much as duty cycle of the impul~e~
~8 ~7~3~ _ 1 even bet~een 25% and 50%. Hence, changing the duty cycle does 2 not significantly change the 10w rate, all else being the ~ame~
3 however, the number of impulse injections per second varie~ the 4 flow rate linearly.
In operation, the pressure in the w~fer processing chamber 2 6 i~ controlled by the combined action of vacuum valve 5, the 7 feedback control system including unit~ 42 t 43, 44, TBI drivsr 8 circuit Z8 and TBI 20, and the temperature i~ controlled by electric power to the heater pads 43 and 44 from temper~ture 0 contro].ler 47. Thus, temperature and pressure in the processing ~1 chamber are maintained as d~ctated by a program in CPU 43. Thl~
12 electrical feedback sy~tem feeds electrical energizing impulses ~3 to TBI ~0 and controls reagent line valve 33 that controls the 14 flow of liquid HMDS to the TsI. CPU 43 may also control the flow of nitrogen gas from a source through valve 52 into the top of IG the HMDS reagent tank 32 to pressurize the tank. The n~trogen is 17 used to vent the top the tank.
19 Conclusions The semiconductor wafer vacuum processing module, its l~qu~d 21 reagent feed system and pres~ure, temperature and gas flow 22 controls de~cribed herein is capable of handling volatile liquld 23 fluids at safe conditions and convertin~ the liquid fluid to gas 2~ at just about any temperature and pressure desired, while at the same time isolating the ga~ contalnlng part~ of ths ~eed sy~tem 2G from the liquid fluid containing parts. This module along with 27 its feed 8y8tem and controls 1~ capable of perorm~ng the 28 proces~ing steps forming clrcuit structure~ on a ~emlconductor ~ 53~ ~
1 wafer of: Prime, ~oftbake, ~ardbake, and Silylatlon, without 2 interruption and without opening the module to remove, replace or 3 otherwise treat the wafer; and all of these steps are dry 4 processing steps, inasmuch as the wafer is exposed only to vacuum or gas and ls not exposed to liquid fluids.
6 It iY suggested that the module described herein its ~eed 7 ~ystem and controls could be adapted to perform by dry processing 8 all other steps from Prime through Silyla~ion followed by 9 reactive ion etching (RIE) using a dry etching pla~ma such as oxygen or a halocarbon plasma.
11 The injector 20 de~cribed herein as an automotive type 12 throttle body injector (TBI) could have sub~tituted therefore ~ other equivalent devices and either the TBI assembly or the 14 equivalent devices could be used to inject other processing 16 chem~cal reagents than HMDS that pose the Rame or similar lG problems that are overcome by use of a TBI type meterlng devlce 17 as disclosed herein. These and other variations and addition to 18 the structure described herein could bè made without deviating 1~ from the spirit and scope of the invention as set forth in the-claims.
222 What is alaimed is:
2¢
21 CPU 43 and the FB signal~ Those pulses are fed via line 44a to 22 TBI driver c~rcuits 28. When the differential pres~ure is large, the pulse rate is high and when the diferential i3 small, the 24 pulse rate is low and may approach zero as the dlfferential approache~ zero. If chamber pressure exceeds the desired or set, 26 pressure, a signal is fed via modulator unit 44 to vacuum source 27 valve 5 causing the valve to open, relieving the chamber pre~sur~
28 ~nto the vacuum source. By thi6 null type feedback control - 18 - " .
. ,.
~ 7~
1 system, the desired or set chamber pressure is produced and 2 maintained.
3 Figure 2 is a plot of processinq chamber pres~ure versus 4 time showing the operation of the system of Figure l where pulse rate is varied or modulated bringing the chamber pre~sure to the 6 desired or set level without overshoot or oscillation around the 7 desired pressure. The plot also ~hows chamber pressure versu3 8 time for a similar system wherein pul~e rate is constant. A
~ system operating with constant pulse rate may reach the desired pressure level quicker, but is likely to overshoot and osc~llate 11 around the deslred pressure.
12 The temperature of the reagent gas in react~on chamber 2 l~
13 controlled by heating pads 45 and 46 that may be embedded in the 14 chamber walls and so the pressure and temperature of the reagent qas and the processing chamber is fully controlled and can ~e 1~ maintained at pressure up to 760 Torr or greater even while the 17 vapor pressure on the reagent tank 32 is no more than 6 Torr (or 18 the vapor pressure of the Reagent at STP). For that purpose, 19 temperature controller 47, controlled by CPU 43 is provided.
Clearly, T~I (metering device 20 isolates proces~ing chamber 21 2 from the tank 32 of liquid reagent. It should al~o be clear 22 that the line 31 carrying liquid Reagent from the tank to the 23 injector can be a very small diameter llne go that the total ~4 quantity of reagent contained ln that line and throughout the 25- module 1 i9 a very small quantity and 80 create5 minimal hazard.
2G The volume of liqu~d over a range of pres9ures ranging from 27 5 p9i to 20 psi that are in~ected by a TBI in a given number of 28 impulses does not change very much as duty cycle of the impul~e~
~8 ~7~3~ _ 1 even bet~een 25% and 50%. Hence, changing the duty cycle does 2 not significantly change the 10w rate, all else being the ~ame~
3 however, the number of impulse injections per second varie~ the 4 flow rate linearly.
In operation, the pressure in the w~fer processing chamber 2 6 i~ controlled by the combined action of vacuum valve 5, the 7 feedback control system including unit~ 42 t 43, 44, TBI drivsr 8 circuit Z8 and TBI 20, and the temperature i~ controlled by electric power to the heater pads 43 and 44 from temper~ture 0 contro].ler 47. Thus, temperature and pressure in the processing ~1 chamber are maintained as d~ctated by a program in CPU 43. Thl~
12 electrical feedback sy~tem feeds electrical energizing impulses ~3 to TBI ~0 and controls reagent line valve 33 that controls the 14 flow of liquid HMDS to the TsI. CPU 43 may also control the flow of nitrogen gas from a source through valve 52 into the top of IG the HMDS reagent tank 32 to pressurize the tank. The n~trogen is 17 used to vent the top the tank.
19 Conclusions The semiconductor wafer vacuum processing module, its l~qu~d 21 reagent feed system and pres~ure, temperature and gas flow 22 controls de~cribed herein is capable of handling volatile liquld 23 fluids at safe conditions and convertin~ the liquid fluid to gas 2~ at just about any temperature and pressure desired, while at the same time isolating the ga~ contalnlng part~ of ths ~eed sy~tem 2G from the liquid fluid containing parts. This module along with 27 its feed 8y8tem and controls 1~ capable of perorm~ng the 28 proces~ing steps forming clrcuit structure~ on a ~emlconductor ~ 53~ ~
1 wafer of: Prime, ~oftbake, ~ardbake, and Silylatlon, without 2 interruption and without opening the module to remove, replace or 3 otherwise treat the wafer; and all of these steps are dry 4 processing steps, inasmuch as the wafer is exposed only to vacuum or gas and ls not exposed to liquid fluids.
6 It iY suggested that the module described herein its ~eed 7 ~ystem and controls could be adapted to perform by dry processing 8 all other steps from Prime through Silyla~ion followed by 9 reactive ion etching (RIE) using a dry etching pla~ma such as oxygen or a halocarbon plasma.
11 The injector 20 de~cribed herein as an automotive type 12 throttle body injector (TBI) could have sub~tituted therefore ~ other equivalent devices and either the TBI assembly or the 14 equivalent devices could be used to inject other processing 16 chem~cal reagents than HMDS that pose the Rame or similar lG problems that are overcome by use of a TBI type meterlng devlce 17 as disclosed herein. These and other variations and addition to 18 the structure described herein could bè made without deviating 1~ from the spirit and scope of the invention as set forth in the-claims.
222 What is alaimed is:
2¢
Claims (24)
1. Apparatus for dry processing a semiconductor wafer in the manufacture of circuit patterns thereon comprising, (a) a vacuum chamber for containing said semiconductor wafer to be processed, (b) an opening into said chamber for the flow of a processing fluid in gaseous form into said chamber, (c) a source of said processing fluid in liquid form, (d) between said source of processing fluid in liquid form and said chamber opening, a fluid meter having a liquid fluid input and an output into a relatively low pressure evaporation chamber that connects to said opening into said processing chamber for converting said metered fluid into metered gas fluid, said metered gas fluid being isolated from said liquid fluid by said fluid meter, and (e) means for energizing said fluid meter, and (f) whereby said fluid meter passes liquid fluid from said source in metered quantities into said evaporation chamber as a mixture of gas and vapor and said mixture is substantially all converted into gas that flows through said opening into said processing chamber.
2. Apparatus as in claim 1 wherein (a) a liquid fluid trap is provided between said fluid meter output and said processing chamber.
3. Apparatus as in claim 1 wherein (a) means are provided for controlling and monitoring the pressure and temperature in said processing chamber and for controlling the flow of said processing fluid in liquid form to said fluid meter to maintain a predetermined pressure and temperature in said processing chamber.
4. Apparatus as in claim 3 wherein (a) said fluid meter is energized in impulses and (b) said flow of said processing fluid in liquid form is increased by increasing the impulse rate of said fluid meter energization.
5. Apparatus as in claim 4 wherein (a) the flow of said processing fluid in gaseous form into said processing chamber is directly proportional to said fluid meter energization impulse rate.
6. Apparatus as in claim 5 wherein said fluid meter is constructed and operated similar to an automotive throttle body injector (TBI) of the sort that feeds gasoline to an automobile engine.
7. Apparatus as in claim 1 wherein said fluid meter is constructed and operated similar to an automotive throttle body injector (TBI) of the sort that feeds gasoline to an automobile engine.
8. Apparatus as in claim 2 wherein said fluid meter is constructed and operated similar to an automotive throttle body injector (TBI) of the sort that feeds gasoline to an automobile engine.
9. In apparatus for dry processing a semiconductor wafer that includes a vacuum processing chamber that contains the semiconductor wafer to be processed, an opening into said chamber for the flow of processing gas into said chamber and a source of processing fluid in liquid form, the improvement comprising, (a) means defining a fluid flow path between said source of processing fluid in liquid form and said opening for converting said liquid fluid into gas fluid whereby said gas fluid is isolated from said liquid fluid, (b) a liquid fluid conduit is provided for said liquid fluid from said source to said converting means at essentially the same temperature and pressure as said liquid fluid at said source, (c) said converting means includes metering means having a liquid fluid input and an output into a relatively low pressure evaporation chamber that connects to said opening into said processing chamber and (d) means for driving said metering means, (e) whereby said metering passes liquid fluid from said source in metered quantities into said evaporation chamber as a mixture of gas and vapor in said mixture is substantially all converted into gas that flows through said opening into said processing chamber.
10. Apparatus as in claim 9 wherein (a) a liquid fluid trap is provided between said metering means output and said processing chamber.
11. Apparatus as in claim 9 wherein (a) means are provided for controlling and monitoring the pressure and temperature in said processing chamber and for controlling the flow of said processing fluid in liquid form to said metering means to maintain predetermined pressure and temperature in said processing chamber.
12. Apparatus as in claim 11 wherein (a) said flow of said processing fluid in liquid form is increased by increasing the energization rate of said metering means.
13. Apparatus as in claim 12 wherein (a) said flow of said processing fluid in gaseous form into said processing chamber is directly proportional to said energization rate of said metering means.
14. Apparatus as in claim 13 wherein said metering means is constructed and operated similar to an automotive throttle body injector (TBI) of the sort that feeds gasoline to an automobile engine.
15. A method of performing a dry process on a semiconductor wafer in a closed processing chamber in the manufacture of circuit patterns thereon including the steps of:
(a) providing a source of processing fluid in liquid form, (b) metering said processing fluid from said source in liquid form at the rate said processing fluid is used in said processing chamber, (c) cyclically passing minute metered quantities of said processing fluid in liquid form into a relatively low pressure chamber that connects to said processing chamber, and (d) accompanied by heating said relatively low pressure chamber.
(a) providing a source of processing fluid in liquid form, (b) metering said processing fluid from said source in liquid form at the rate said processing fluid is used in said processing chamber, (c) cyclically passing minute metered quantities of said processing fluid in liquid form into a relatively low pressure chamber that connects to said processing chamber, and (d) accompanied by heating said relatively low pressure chamber.
16. A method as in claim 15 wherein (a) said cyclic passing is done by forcing said minute quantities of said processing fluid in liquid form into said relatively low pressure chamber that connects to said processing chamber.
17. A method as in claim 15 wherein the flow of said processing fluid in liquid form for cyclic converting to gas is controlled by varying the rate of said passing.
18. A method as in claim 15 wherein the flow of said processing fluid in liquid form for cyclic converting to gas is controlled by varying the duty cycle of said cycles.
19. In apparatus for dry processing a semiconductor wafer that includes a vacuum processing chamber that contains the semiconductor wafer to be processed, an opening into said chamber for the flow of processing gas into said chamber, a source of processing fluid in liquid form, a fluid flow path between said source of processing fluid in liquid form and said opening for converting said liquid fluid into gas fluid, said converting means includes an impulse type fluid injector, means for energizing said impulse injector so that it draws liquid fluid from said source and injects minute quantities of said fluid into said evaporation chamber as a mixture of gas and vapor wherein said mixture is substantially all converted into gas that flows through said opening into said processing chamber, means for controlling said impulse injector to maintain a predetermined chamber pressure comprising, (a) means for detecting pressure in said chamber, producing a signal representative thereof, herein called the chamber pressure signal, (b) a source of control pulses for said impulse injector, and (c) means for modulating said control pulses in response to said pressure signal.
20. Apparatus as in claim 19 wherein said means for modulating modulates the rate of said control pulses.
21. Apparatus as in claim 20 wherein said rate of control pulses is modulated so that said rate is least when said chamber pressure is at said predetermined chamber pressure.
22. Apparatus as in claim 21 wherein, (a) means are provided producing a signal representative of said predetermined chamber pressure, (b) means are provided for comparing said detected chamber pressure and said predetermined chamber pressure producing a signal representative of the difference, and (c) said pulse rate is proportional to said difference signal.
23. Apparatus as in claim 22 wherein said rate of control pulses is proportional to said difference when said detected chamber pressure is less than said predetermined chamber pressure.
24. Apparatus as in claim 23 wherein injection by said injector stops when said detected chamber pressure is greater than said predetermined chamber pressure.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US07/024,828 US4768291A (en) | 1987-03-12 | 1987-03-12 | Apparatus for dry processing a semiconductor wafer |
| US024,828 | 1987-03-12 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1286794C true CA1286794C (en) | 1991-07-23 |
Family
ID=21822592
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000561382A Expired - Fee Related CA1286794C (en) | 1987-03-12 | 1988-03-14 | Apparatus for dry processing a semiconductor wafer |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US4768291A (en) |
| EP (1) | EP0305517A1 (en) |
| JP (1) | JPH01503584A (en) |
| CA (1) | CA1286794C (en) |
| WO (1) | WO1988007263A2 (en) |
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| US5094936A (en) * | 1988-09-16 | 1992-03-10 | Texas Instruments Incorporated | High pressure photoresist silylation process and apparatus |
| DE68926480T2 (en) * | 1988-09-16 | 1996-10-02 | Texas Instruments Inc | High pressure photoresist siliconization process and device |
| JPH02151865A (en) * | 1988-11-22 | 1990-06-11 | Ucb Sa | High-temperature reaction treatment |
| US5174855A (en) * | 1989-04-28 | 1992-12-29 | Dainippon Screen Mfg. Co. Ltd. | Surface treating apparatus and method using vapor |
| US5041362A (en) * | 1989-07-06 | 1991-08-20 | Texas Instruments Incorporated | Dry developable resist etch chemistry |
| US5138643A (en) * | 1989-10-02 | 1992-08-11 | Canon Kabushiki Kaisha | Exposure apparatus |
| AU7961391A (en) * | 1990-05-15 | 1991-12-10 | Semitool, Inc. | Semiconductor processor apparatus with dynamic wafer vapor treatment and particle volatilization |
| US5228208A (en) * | 1991-06-17 | 1993-07-20 | Applied Materials, Inc. | Method of and apparatus for controlling thermal gradient in a load lock chamber |
| US5332444A (en) * | 1992-11-25 | 1994-07-26 | Air Products And Chemicals, Inc. | Gas phase cleaning agents for removing metal containing contaminants from integrated circuit assemblies and a process for using the same |
| US5644855A (en) * | 1995-04-06 | 1997-07-08 | Air Products And Chemicals, Inc. | Cryogenically purged mini environment |
| US6206970B1 (en) * | 1997-09-03 | 2001-03-27 | Micron Technology, Inc. | Semiconductor wafer processor, semiconductor processor gas filtering system and semiconductor processing methods |
| US6603510B1 (en) * | 1997-12-08 | 2003-08-05 | Intel Corporation | Formation of protective coatings for color filters |
| US6683006B2 (en) * | 2001-06-25 | 2004-01-27 | Tokyo Electron Limited | Film forming method and film forming apparatus |
| US7541200B1 (en) | 2002-01-24 | 2009-06-02 | Novellus Systems, Inc. | Treatment of low k films with a silylating agent for damage repair |
| US7192486B2 (en) * | 2002-08-15 | 2007-03-20 | Applied Materials, Inc. | Clog-resistant gas delivery system |
| WO2004088415A2 (en) * | 2003-03-28 | 2004-10-14 | Advanced Technology Materials Inc. | Photometrically modulated delivery of reagents |
| US7063097B2 (en) * | 2003-03-28 | 2006-06-20 | Advanced Technology Materials, Inc. | In-situ gas blending and dilution system for delivery of dilute gas at a predetermined concentration |
| US7727588B2 (en) * | 2003-09-05 | 2010-06-01 | Yield Engineering Systems, Inc. | Apparatus for the efficient coating of substrates |
| US20050051087A1 (en) * | 2003-09-08 | 2005-03-10 | Taiwan Semiconductor Manufacturing Co., Ltd., | Primer tank with nozzle assembly |
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| US8084866B2 (en) | 2003-12-10 | 2011-12-27 | Micron Technology, Inc. | Microelectronic devices and methods for filling vias in microelectronic devices |
| US20050247894A1 (en) | 2004-05-05 | 2005-11-10 | Watkins Charles M | Systems and methods for forming apertures in microfeature workpieces |
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| US7425499B2 (en) | 2004-08-24 | 2008-09-16 | Micron Technology, Inc. | Methods for forming interconnects in vias and microelectronic workpieces including such interconnects |
| SG120200A1 (en) * | 2004-08-27 | 2006-03-28 | Micron Technology Inc | Slanted vias for electrical circuits on circuit boards and other substrates |
| US7300857B2 (en) * | 2004-09-02 | 2007-11-27 | Micron Technology, Inc. | Through-wafer interconnects for photoimager and memory wafers |
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| US7795134B2 (en) * | 2005-06-28 | 2010-09-14 | Micron Technology, Inc. | Conductive interconnect structures and formation methods using supercritical fluids |
| US20070045120A1 (en) * | 2005-09-01 | 2007-03-01 | Micron Technology, Inc. | Methods and apparatus for filling features in microfeature workpieces |
| US7863187B2 (en) * | 2005-09-01 | 2011-01-04 | Micron Technology, Inc. | Microfeature workpieces and methods for forming interconnects in microfeature workpieces |
| US7622377B2 (en) | 2005-09-01 | 2009-11-24 | Micron Technology, Inc. | Microfeature workpiece substrates having through-substrate vias, and associated methods of formation |
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| US7749899B2 (en) * | 2006-06-01 | 2010-07-06 | Micron Technology, Inc. | Microelectronic workpieces and methods and systems for forming interconnects in microelectronic workpieces |
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| US7902643B2 (en) * | 2006-08-31 | 2011-03-08 | Micron Technology, Inc. | Microfeature workpieces having interconnects and conductive backplanes, and associated systems and methods |
| US8221557B2 (en) * | 2007-07-06 | 2012-07-17 | Micron Technology, Inc. | Systems and methods for exposing semiconductor workpieces to vapors for through-hole cleaning and/or other processes |
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| US3236073A (en) * | 1963-12-23 | 1966-02-22 | Hupp Corp | Coin operated dry cleaning system |
| US3943904A (en) * | 1974-07-19 | 1976-03-16 | General Motors Corporation | Single injector throttle body |
| US4556785A (en) * | 1983-05-23 | 1985-12-03 | Gca Corporation | Apparatus for vapor sheathed baking of semiconductor wafers |
| US4592926A (en) * | 1984-05-21 | 1986-06-03 | Machine Technology, Inc. | Processing apparatus and method |
| US4551418A (en) * | 1985-02-19 | 1985-11-05 | International Business Machines Corporation | Process for preparing negative relief images with cationic photopolymerization |
-
1987
- 1987-03-12 US US07/024,828 patent/US4768291A/en not_active Expired - Fee Related
-
1988
- 1988-03-14 WO PCT/US1988/000961 patent/WO1988007263A2/en not_active Application Discontinuation
- 1988-03-14 JP JP63507083A patent/JPH01503584A/en active Pending
- 1988-03-14 EP EP88904750A patent/EP0305517A1/en not_active Withdrawn
- 1988-03-14 CA CA000561382A patent/CA1286794C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| EP0305517A1 (en) | 1989-03-08 |
| JPH01503584A (en) | 1989-11-30 |
| US4768291A (en) | 1988-09-06 |
| WO1988007263A3 (en) | 1988-10-06 |
| WO1988007263A2 (en) | 1988-09-22 |
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