Gas Or Vapor Condensation Or Absorption On Work Patents (Class 134/31)
  • Patent number: 5332445
    Abstract: Disclosed are methods and apparatuses for improved etching of semiconductor wafers and the like using hydrofluoric acid (HF) and water mixtures or solutions which generate equilibrium vapor mixtures of HF vapor and water vapor which serve as a homogenous etchant gas. The vapor etchants do not employ a carrier gas which will make the vapors nonhomogeneous and reduce etching rates. The vapors are preferably generated from a liquid source which is provided within a contained reaction chamber which holds the wafer. The wafer is preferably oriented with the surface being processed directed downward. The wafer is advantageously positioned above or in close proximity to the equilibrium liquid source of the vapor. The wafer is rotated at a rotational speed in the range of 20-1000 revolutions per minute to provide uniform dispersion of the homogeneous etchant gas across the wafer surface and to facilitate circulation and transfer from the liquid source into etchant gas and onto the processed surface.
    Type: Grant
    Filed: September 30, 1992
    Date of Patent: July 26, 1994
    Assignee: Semitool, Inc.
    Inventor: Eric J. Bergman
  • Patent number: 5320683
    Abstract: A hydrochlorofluoropropane azeotropic or azeotropic-like composition comprising at least two members selected from the group consisting of hydrochlorofluoropropanes of the formula I:CH.sub.a Cl.sub.b F.sub.c CF.sub.2 CH.sub.x Cl.sub.y F.sub.z (I)wherein a+b+c=3, x+y+z=3, a+x.gtoreq.1, b+y.gtoreq.1, and 0.ltoreq.a,b,c,x,y,z.ltoreq.3.
    Type: Grant
    Filed: September 4, 1992
    Date of Patent: June 14, 1994
    Assignee: Asahi Glass Company Ltd.
    Inventors: Shunichi Samejima, Kenroh Kitamura, Naohiro Watanabe, Teruo Asano, Toru Kamimura, Shinsuke Morikawa
  • Patent number: 5311671
    Abstract: Apparatus for recovering from a filter element a dry cleaning fluid, the vapor of which is more dense than air, is disclosed. The apparatus comprises a chamber, a support for a filter cartridge, a heating element, and a cooling element located below the heating element.
    Type: Grant
    Filed: March 23, 1993
    Date of Patent: May 17, 1994
    Inventors: Floyd L. Brooks, James E. Gilchrist
  • Patent number: 5308528
    Abstract: For replacing cleaning compositions based on 1,1,2-trichloro-1,2,2-trifluoroethane (F113), the invention provides a composition comprising 55 to 80% by weight of 1,1-dichloro-1-fluoroethane (F141b) and 45 to 20% by weight of methyl formate. These two compounds form a positive azeotrope (b.p.=28.4.degree. C. at atmospheric pressure).The composition, which may be stabilized, can be used for cleaning solid surfaces, in particular for removing flux from printed circuits and for degreasing mechanical parts.
    Type: Grant
    Filed: February 7, 1991
    Date of Patent: May 3, 1994
    Assignee: Societe Atochem
    Inventors: Daniel Desbiendras, Jean-Jacques Martin, Pascal Michaud
  • Patent number: 5304253
    Abstract: A method is provided for cleaning an article with a solvent having a boiling point such that the solvent is a gas at room temperature and one atmosphere pressure. Such a method includes the steps of disposing the article in a chamber, introducing the solvent into the chamber so that the solvent contacts the article, pressurizing the chamber so that the solvent is in a liquid state and removes contaminants from the article, purging the chamber to remove the solvent, and removing the treated article from the chamber. Such a system permits the use of liquids having boiling points lower than room temperature, such as certain C.sub.1 -C.sub.4 halocarbons, which liquids have not previously been used as cleaning solvents.
    Type: Grant
    Filed: February 25, 1992
    Date of Patent: April 19, 1994
    Assignee: Baxter International Inc.
    Inventor: David C. H. Grant
  • Patent number: 5304321
    Abstract: Compositions suitable for use in cleaning processes formed of hydrogen-containing fluorochlorohydrocarbons selected from the group of consisting of tetrachloromonofluoroethanes, trichlorodifluoroethanes, dichlorotrifluoroethanes, dichloromonofluoroethanes and dichloropentafluoropropanes or a mixture one or more of these hydrogen-containing fluorochlorohydrocarbons in admixture with partially fluorinated alkanols containing two to four carbon atoms.
    Type: Grant
    Filed: March 13, 1992
    Date of Patent: April 19, 1994
    Assignee: Kali-Chemie AG
    Inventors: Hans Buchwald, Andreas Brackmann, Boleslaus Raszkowski
  • Patent number: 5302212
    Abstract: To replace 1,1,2-trichloro-1,2,2-trifluoroethane (F113) in its applications to the cleaning and drying of solid surfaces, the invention propose to employ a (perfluoroalkyl) ethylene of formula:R.sub.f CH.dbd.CH.sub.2in which R.sub.f denotes a linear or branched perfluoroalkyl radical containing from 3 to 6 carbon atoms.In contrast to F113, (perfluoroalkyl)ethylenes are not liable to degrade stratospheric ozone.
    Type: Grant
    Filed: February 20, 1991
    Date of Patent: April 12, 1994
    Assignee: Societe Atochem
    Inventors: Daniel Desbiendras, Jean-Jacques Martin, Pascal Michaud
  • Patent number: 5300154
    Abstract: The invention relates to methods and compositions for cleaning a wide range of soil types from dirty articles, such as metal, ceramic or glass substrates. A first class of solvent compositions used for cleaning is an oxidative stable mixture of non-polar aromatic hydrocarbons and an organic polar component for cleaning of low and intermediate polar soils. Alternately, water and surfactant is added to the mixture to form a water-in-oil emulsion for cleaning high polarity soils. A second class of solvent compositions used for cleaning dirty articles is a hydrogenated or dehydrogenated analogue of a terpene compound. The solvent composition is used in a process wherein a dirty article is contacted with the solvent under conditions that result in cleaning the soil type from the article. Residual solvent contamination is removed from the article surface by contacting the contaminated article at an elevated temperature with an aqueous medium and/or a low-boiling solvent.
    Type: Grant
    Filed: April 22, 1992
    Date of Patent: April 5, 1994
    Assignee: Bush Boake Allen Limited
    Inventors: Gerald J. Ferber, Graham J. Smith
  • Patent number: 5294262
    Abstract: A method of cleaning a process tube and a wafer boat, comprising the steps of, carrying wafers out of the process tube, controlling the temperature in the process tube saw as or lower than a process temperature and higher than a boiling point of ClF.sub.3, said process temperature being kept in the process tube when the process of forming film on the wafers is carried out in the process tube, and supplying ClF.sub.3 -contained cleaning gas into the process tube to react the cleaning gas with the film of the silicon oxide adhering to the inner wall of the process tube and the wafer boat.
    Type: Grant
    Filed: June 24, 1993
    Date of Patent: March 15, 1994
    Assignee: Tokyo Electron Limited
    Inventor: Toshiharu Nishimura
  • Patent number: 5289690
    Abstract: The invention disclosed herein relates to an apparatus for being detachably connected to a chemical or refrigeration system for selectively receiving and dispensing a gaseous refrigerant or chemical from and to that system, respectively, including a vessel having a chamber capable of maintaining a pressurized gas therein, gas inlet means for directing the gas: to and from the chamber, and connection means for connecting the gas inlet to a refrigeration or chemical system; a plurality of heat exchange conduits exposed in the chamber for directing heat exchange fluid therethrough and fluid inlet and outlet means communicating exteriorly of the vessel for directing the fluid to and from the conduits, respectively; and a solid adsorbent capable of alternately adsorbing and desorbing the gaseous refrigerant or chemical and positioned in thermal communication with each of the heat exchange conduits.
    Type: Grant
    Filed: August 6, 1992
    Date of Patent: March 1, 1994
    Assignee: Rocky Research
    Inventors: Uwe Rockenfeller, Lance D. Kirol
  • Patent number: 5290473
    Abstract: Stable azeotrope-like compositions of 1,1,1,3,3,5,5,5-octafluoropentane, C.sub.1 -C.sub.5 alkanol and optionally nitromethane have been discovered which are useful as degreasing agents and as solvents in a variety of industrial cleaning applications including cold cleaning and defluxing of printed circuit boards and dry cleaning.
    Type: Grant
    Filed: March 15, 1993
    Date of Patent: March 1, 1994
    Assignee: AlliedSignal Inc.
    Inventors: Rajat S. Basu, Ellen L. Swan
  • Patent number: 5288422
    Abstract: Azeotrope-like compositions comprising 1,1,1,3,3,5,5,5-octafluoropentane, chlorinated ethylene and optionally nitromethane have been discovered which are stable and have utility as degreasing agents and as solvents in a variety of industrial cleaning applications including cold cleaning and defluxing of printed circuit boards and dry cleaning.
    Type: Grant
    Filed: March 15, 1993
    Date of Patent: February 22, 1994
    Assignee: AlliedSignal Inc.
    Inventors: Rajat S. Basu, Ellen L. Swan, David P. Wilson
  • Patent number: 5288333
    Abstract: A wafer cleaning method and apparatus in which a cleaning solution is caused to evaporate at a temperature below its boiling point, and cleaning vapor thus produced is applied at a temperature above its dew point to a wafer such as a semiconductor wafer. The wafer is cleaned without formation of colloidal silica in the absence of aerosol, or etched uniformly free of impurities. The wafer cleaning apparatus comprises a cleaning solution storage, a vapor generating section, a wafer supporting position of a wafer supporting device and a vapor supply section. These components are arranged in a housing to overlap one another in plan view and to lie vertically close to one another. The apparatus has a compact overall construction with simplified seals for preventing leakage of the cleaning vapor.
    Type: Grant
    Filed: July 29, 1992
    Date of Patent: February 22, 1994
    Assignee: Dainippon Screen Mfg. Co., Ltd.
    Inventors: Masato Tanaka, Hisao Nishizawa, Nobuyuki Hirai, Kaoru Shinbara, Hitoshi Yoshioka
  • Patent number: 5288819
    Abstract: Azeotrope-like compositions comprising dichloropentafluoropropane and 1,2-dichloroethylene are stable and have utility as degreasing agents and as solvents in a variety of industrial cleaning applications including cold cleaning and defluxing of printed circuit boards.
    Type: Grant
    Filed: February 24, 1992
    Date of Patent: February 22, 1994
    Assignee: AlliedSignal Inc.
    Inventors: Hillel Magid, Richard E. Eibeck, Michael Van Der Puy, Richard M. Hollister, Dennis M. Lavery, David P. Wilson
  • Patent number: 5282925
    Abstract: New device and method are described for accurate etching and removal of thin layer by controlling the surface residence time, thickness and composition of reactant containing film. Etching of silicon dioxide at low pressure using a quartz crystal microbalance is illustrated. Usefulness of the invention in the manufacture of microelectronic devices is shown.
    Type: Grant
    Filed: November 9, 1992
    Date of Patent: February 1, 1994
    Assignee: International Business Machines Corporation
    Inventors: Shwu-Jen Jeng, Wesley C. Natzle, Chienfan Yu
  • Patent number: 5279615
    Abstract: The invention provides a method and composition for the removal of nonpolar stains from a fabric comprising:contacting said stains with densified carbon dioxide and a cleaning adjunct in mixture with said carbon dioxide.
    Type: Grant
    Filed: June 14, 1991
    Date of Patent: January 18, 1994
    Assignee: The Clorox Company
    Inventors: James D. Mitchell, Daniel T. Carty, James R. Latham
  • Patent number: 5273589
    Abstract: An embodiment of the present invention is a system for rinsing and drying items comprising a process chamber for receiving the items; a rinse condenser; a first heater; a vaporizer for vaporizing water and including a second heater; a vacuum system for reducing the pressure within the process chamber; and a valving apparatus for independently coupling the process chamber to the vaporizer and the process chamber to the vacuum system.
    Type: Grant
    Filed: July 10, 1992
    Date of Patent: December 28, 1993
    Inventors: Bradley L. Griswold, Syed A. Husain
  • Patent number: 5271774
    Abstract: A method is set forth of removing a liquid (3) from a surface (2) of a substrate (1), which is placed in a centrifuge (4) and is then subjected therein to a rotary movement, the substrate being rotated at such a speed that the liquid is centrifuged from the surface. According to the invention, the substrate is brought into contact in the centrifuge with a vapour of a material which is miscible with the liquid and which, when mixed therewith, yields a mixture having a surface tension which is lower than that of the liquid. Due to this step, the quantity of material remaining on the surface is strongly reduced.
    Type: Grant
    Filed: March 5, 1992
    Date of Patent: December 21, 1993
    Assignee: U.S. Philips Corporation
    Inventors: Adriaan F. M. Leenaars, Johanna A. M. Huethorst, Johannes Marra
  • Patent number: 5269943
    Abstract: A method for treating soil contaminated by organic compounds wherein an ozone containing gas is treated with acid to increase the stability of the ozone in the soil environment and the treated ozone applied to the contaminated soil to decompose the organic compounds. The soil may be treated in situ or may be removed for treatment and refilled.
    Type: Grant
    Filed: July 13, 1992
    Date of Patent: December 14, 1993
    Assignee: Battelle Memorial Institute
    Inventor: Godage B. Wickramanayake
  • Patent number: 5269878
    Abstract: After a metal deposition is patterned using a plasma etch, the metal pattern is sprayed with steam and water. During the spraying the wafer is rotated to ensure proper distribution and removal of the spray. The spray removes chlorine residue from the etch that might otherwise corrode the metal pattern. After the spray, the spin rate is increased to dry the wafer. The net result is a faster and more effective method for chlorine removal from a plasma-etched metal pattern.
    Type: Grant
    Filed: December 10, 1992
    Date of Patent: December 14, 1993
    Assignee: VLSI Technology, Inc.
    Inventors: Allen Page, Stacy W. Hall
  • Patent number: 5268069
    Abstract: Anhydrous ammonium fluoride is used as a safe source of hydrogen fluoride for etching native or other silicon dioxide layers from silicon substrates. Heating the anhydrous ammonium fluoride above its sublimation temperature results in the generation of hydrogen fluoride gas which etches the silicon dioxide. Controlled amounts of water vapor are used during the etch reaction to ensure complete etching of the thin oxide layers down to within hundredths of a monolayer and to achieve precise etch rate control.
    Type: Grant
    Filed: June 8, 1992
    Date of Patent: December 7, 1993
    Assignee: International Business Machines Corporation
    Inventors: Jonathan D. Chapple-Sokol, Richard A. Conti, David E. Kotecki, Andrew H. Simon, Manu Tejwani
  • Patent number: 5268121
    Abstract: To replace cleaning compositions based on 1,1,2-trichloro-1,2,2-trifluoroethane (F113), the invention proposes a composition comprising, by weight, 93 to 99% of 1,1,1,3,3-pentafluorobutane (F365 mfc) and 7 to 1% of methanol. These two compounds form a positive azeotrope (b.p.=36.5.degree. C. at normal pressure).The composition, optionally stabilized, can be used for the cleaning and/or drying of solid surfaces, in particular for the removal of flux from printed circuits and for degreasing mechanical parts.
    Type: Grant
    Filed: April 30, 1992
    Date of Patent: December 7, 1993
    Assignee: Elf Atochem, S.A.
    Inventor: Pascal Michaud
  • Patent number: 5268120
    Abstract: To replace the cleaning compositions based on 1,1,2-trichloro-1,2,2-trifluoroethane (F113), the invention proposes a composition comprising, on a weight basis, 60 to 90% of 1,1-dichloro-1-fluoroethane (F141b), 9 to 33% of 1,1,1,3,3-pentafluorobutane (F365 mfc) and 1 to 7% of methanol. These three compounds form a positive azeotrope (b.p.=29.1.degree. C. at normal pressure).The composition, optionally stabilized, can be employed for the cleaning and/or drying of solid surfaces, in particular for the defluxing of printed circuits and for the degreasing of mechanical components.
    Type: Grant
    Filed: April 30, 1992
    Date of Patent: December 7, 1993
    Assignee: Elf Atochem, S.A.
    Inventor: Pascal Michaud
  • Patent number: 5266232
    Abstract: The invention relates to an azeotrope-like mixture which contains about 5-9% by weight of methanol and about 91-95% by weight of 1 H-perfluorohexane and to a process for cleaning electronic components, in particular soldered circuit boards or printed circuits, with the aid of this mixture.
    Type: Grant
    Filed: June 18, 1992
    Date of Patent: November 30, 1993
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Horst Robeck, Hans-Matthias Deger
  • Patent number: 5266231
    Abstract: The invention relates to an azeotrope-like mixture which contains about 8-12% by weight of 2-propanol and about 88-92% by weight of 1H-perfluorohexane and to a process for cleaning electronic components, in particular soldered circuit boards or printed circuits, with the aid of this mixture.
    Type: Grant
    Filed: June 18, 1992
    Date of Patent: November 30, 1993
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Horst Robeck, Hans-Matthias Deger
  • Patent number: 5261966
    Abstract: For cleaning semiconductor wafers in a cleaning vessel by supplying a cleaning fluid through a supply line thereto, a mixer is provided. Deionized water is supplied to the mixer through a deionized water supply line, and a cleaning gas is supplied thereto from a gas reservoir to produce the cleaning fluid. After treating the semiconductor wafers with the cleaning fluid, the deionized water is supplied to the cleaning vessel to rinse them.
    Type: Grant
    Filed: January 24, 1992
    Date of Patent: November 16, 1993
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Noriyoshi Mashimo, Katsuya Okumura
  • Patent number: 5259983
    Abstract: Azeotrope-like compositions comprising 1-H-perfluorohexane and trifluoroethanol or n-propanol and optionally nitromethane are stable and have utility as degreasing agents and as solvents in a variety of industrial cleaning applications including cold cleaning and defluxing of printed circuit boards and dry cleaning.
    Type: Grant
    Filed: April 27, 1992
    Date of Patent: November 9, 1993
    Assignee: Allied Signal Inc.
    Inventors: Michael Van Der Puy, Richard E. Eibeck
  • Patent number: 5256208
    Abstract: Volatile organic compounds and other volatile contaminants are removed from soils and granular solids by contacting the soil with steam at superatmospheric pressure and thereafter rapidly reducing the pressure by flashing off steam and vaporized contaminants leaving a cleaned soil product. The steam fraction containing the contaminant compounds is condensed and the contaminants can then be separated from the water for recovery or disposal.
    Type: Grant
    Filed: October 1, 1991
    Date of Patent: October 26, 1993
    Inventor: Harold J. Rafson
  • Patent number: 5250208
    Abstract: Azeotropic or azeotrope-like compositions of effective amounts of 1,1,2,2,3,3,4,4,-octofluorobutane; trans-1,2-dichloroethylene, cis-1,2-dichloroethylene, 1,1-dichloroethane, or 1,3-dichloro-1,2,2,3,3-HCFC-225cb; and an alcohol such as methanol, ethanol, or isopropanol, to form an azeotropic or azeotrope-like composition are disclosed that are useful as cleaning agents, refrigerants, aerosol propellants, heat transfer media, gaseous dielectrics, fire extinguishing agents, expansion agents for polyolefins and polyurethanes and as power cycle working fluids.
    Type: Grant
    Filed: April 2, 1992
    Date of Patent: October 5, 1993
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Abid N. Merchant, Janet C. Sung
  • Patent number: 5248380
    Abstract: A surface treatment method of treating a main surface of a wafer by a surface treating gas while rotating the wafer at a predetermined rotation speed includes the steps of: determining, before surface treatment of the product wafer, a first rotation speed at which the result of a comparison between the speed of surface treatment in the center of rotation of the main surface of a product wafer and the speed of surface treatment in the periphery of it is inverted; and supplying a surface treating gas to the main surface of the product wafer while rotating the product wafer at the determined first rotation speed. The first rotation speed is selected to be corresponding to the inflection point of a curved line of a function which represents the relation between the surface treatment rate and the rotation speed of the wafer. Surface treatment is carried out at uniform treatment rate over the whole surface of the wafer by rotating the wafer the first rotation speed.
    Type: Grant
    Filed: November 6, 1991
    Date of Patent: September 28, 1993
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Masato Tanaka
  • Patent number: 5246617
    Abstract: Azeotropic mixtures of 1,1-dichloro-1-fluoroethane (HCFC-141b) with methanol or ethanol, the azeotropic mixtures being useful in solvent cleaning applications.
    Type: Grant
    Filed: January 20, 1988
    Date of Patent: September 21, 1993
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Abid N. Merchant, Akimichi Yokozeki
  • Patent number: 5242502
    Abstract: Disclosed is a method and degreasing apparatus for cleaning articles. The articles are contacted with a chlorinated benzotrifluoride liquid which is subsequently washed from the articles using liquid methylene chloride. The degreaser includes means for applying the liquids to the articles and can also include means for evaporating some of the methylene chloride to render vapors of the chlorinated benzotrifluoride nonflammable.
    Type: Grant
    Filed: June 2, 1992
    Date of Patent: September 7, 1993
    Assignee: Occidental Chemical Corporation
    Inventor: Edward A. Rowe
  • Patent number: 5238500
    Abstract: Disclosed are methods and apparatuses for combined etching and cleaning of semiconductor wafers and the like preferably using hydrofluoric acid (HF), hydrochloric acid (HCl) and water solutions which generate equilibrium vapor mixtures of HF vapor, HCl vapor and water vapor as a homogenous processing gas. The processing gases do not employ a carrier gas which will make the vapors nonhomogeneous and reduce etching rates. The vapors are preferably generated from a liquid source which is provided within a contained reaction chamber which holds the wafer. The wafer is preferably oriented with the surface being processed directed downward. The wafer is advantageously positioned above or in close proximity to the liquid source of the processing vapor.
    Type: Grant
    Filed: May 21, 1990
    Date of Patent: August 24, 1993
    Assignee: Semitool, Inc.
    Inventor: Eric J. Bergman
  • Patent number: 5238871
    Abstract: A method of manufacturing a semiconductor device including a MOS-type field effect transistor includes cleansing a surface of a substrate; forming, next to the cleansing step, a gate oxide film on the cleansed surface of the substrate; wherein the cleansing step includes dry-etching the surface of the substrate in an atmosphere in which hydrogen fluoride and a substance containing at least a chlorine atom coexist in gaseous state and removing an oxide film and metal impurities on the surface of the substrate. Preferably, the dry-etching is performed under heat and decompression.
    Type: Grant
    Filed: November 25, 1991
    Date of Patent: August 24, 1993
    Assignee: Seiko Epson Corporation
    Inventor: Masato Sato
  • Patent number: 5232511
    Abstract: Disclosed are methods and apparatuses for combined etching and cleaning of semiconductor wafers and the like using a combined etchant and cleaning agent, particularly hydrofluoric acid (HF) and hydrochloric acid in water mixtures. Homogeneous vapor mixtures are generated from homogeneous liquid phase mixtures which are preferably recirculated, mixed and agitated. The liquid phase is advantageously circulated through a chemical chamber within the processing bowl. Exposure of wafers to vapors from the chemical chamber can be controlled by a vapor control valve which is advantageously the bottom of the processing chamber. The wafer is rotated or otherwise moved within the processing chamber to provide uniform dispersion of the homogeneous reactant vapors across the wafer surface and to facilitate vapor circulation to the processed surface. A radiative volatilization processor can be utilized to volatilize reaction by-products which form under some conditions.
    Type: Grant
    Filed: March 6, 1991
    Date of Patent: August 3, 1993
    Assignee: Semitool, Inc.
    Inventor: Eric J. Bergman
  • Patent number: 5227087
    Abstract: Constant boiling, azeotrope-like mixtures of dichlorotrifluoroethane, 1,1-dichloro-1-fluoroethane and methanol and/or ethanol, the constant-boiling, azeotrope-like mixtures being useful in solvent cleaning applications.
    Type: Grant
    Filed: January 17, 1989
    Date of Patent: July 13, 1993
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Abid N. Merchant
  • Patent number: 5227088
    Abstract: Azeotrope-like compositions of 1-chloro-3,3,3-trifluoropropane and a hydrocarbon containing five or six carbon atoms have been discovered which are useful in a variety of applications including industrial cleaning, blowing agent and aerosol applications.
    Type: Grant
    Filed: November 26, 1991
    Date of Patent: July 13, 1993
    Assignee: Allied-Signal Inc.
    Inventors: Ellen L. Swan, Richard M. Hollister, Rajat S. Basu
  • Patent number: 5225099
    Abstract: Azeotrope-like compositions comprising 4-trifluoromethyl-1,1,1,2,2,3,3,5,5,5-decafluoropentane and a second component selected from the group consisting of methanol; ethanol; 1-propanol; 2-propanol; 2-methyl-2-propanol; 2-methyl-2-butanol; n-hexane; isohexane; 2-propanone; and 2-butanone and optionally nitromethane are stable and have utility as degreasing agents and as solvents in a variety of industrial cleaning applications including cold cleaning and defluxing of printed circuit boards and dry cleaning.
    Type: Grant
    Filed: March 16, 1992
    Date of Patent: July 6, 1993
    Assignee: Allied-Signal Inc.
    Inventors: Rajat S. Basu, Richard M. Hollister, Kane D. Cook, Michael Van Der Puy
  • Patent number: 5221493
    Abstract: Azeotropic mixtures of HFC-338pcc and an alcohol such as methanol, ethanol, isopropanol or N-propanol, or a ketone such as acetone, are disclosed that are useful as cleaning agents, refrigerants, aerosol propellants, heat transfer media, gaseous dielectrics, fire extinguishing agents, expansion agents for polyolefins and polyurethanes, power cycle working fluids, polymerization media, particulate removal fluids, carrier fluids, and displacement drying agents.
    Type: Grant
    Filed: October 18, 1991
    Date of Patent: June 22, 1993
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Abid N. Merchant, Allen C. Sievert, Akimichi Yokozeki, Janet C. Sung
  • Patent number: 5221361
    Abstract: Mixtures of the compound 1,1,1,2,2,5,5,5-octafluoro-4-trifluoromethylpentane with alcohols, ethers, esters, ketones, nitrogen-containing organic compounds, and halogenated hydrocarbons are disclosed; as is a process for cleaning a solid surface which comprises treating the surface with said mixtures. Binary mixtures of 1,1,1,2,2,5,5,5-octafluoro-4-trifluoromethylpentane with about 5 to 13 weight percent methanol, with about 2 to 10 weight percent ethanol, with about 3 to 11 weight percent isopropanol, with about 50 to 58 weight percent dichloromethane, and with about 1 to 9 weight percent acetonitrile, are disclosed as azeotrope or azeotrope-like compositions and are particularly suited for use where solvent recovery and reuse is practiced.
    Type: Grant
    Filed: September 4, 1991
    Date of Patent: June 22, 1993
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Douglas R. Anton, Frank J. Weigert
  • Patent number: 5219488
    Abstract: Azeotrope-like compositions comprising 2-trifluoromethyl-1,1,1,2-tetrafluorobutane and ethanol or isopropanol and optionally nitromethane are stable and have utility as degreasing agents and as solvents in a variety of industrial cleaning applications including cold cleaning and defluxing of printed circuit boards and dry cleaning.
    Type: Grant
    Filed: March 16, 1992
    Date of Patent: June 15, 1993
    Assignee: Allied-Signal Inc.
    Inventors: Rajat S. Basu, Ellen L. Swan, Richard M. Hollister
  • Patent number: 5219489
    Abstract: Azeotrope-like compositions comprising 2-trifluoromethyl-1,1,1,2-tetrafluorobutane and methanol are stable and have utility as degreasing agents and as solvents in a variety of industrial cleaning applications including cold cleaning and defluxing of printed circuit boards and dry cleaning.
    Type: Grant
    Filed: August 15, 1991
    Date of Patent: June 15, 1993
    Assignee: Allied-Signal Inc.
    Inventors: Ellen L. Swan, Rajat S. Basu, Michael Van Der Puy
  • Patent number: 5219490
    Abstract: Azeotrope like compositions comprising 1,1,2,3,3,-pentafluoropropane and methanol or ethanol and optionally nitromethane are stable and have utility as degreasing agents and as solvents in a variety of industrial cleaning applications including cold cleaning and defluxing of printed circuit boards and dry cleaning.
    Type: Grant
    Filed: April 27, 1992
    Date of Patent: June 15, 1993
    Assignee: Allied-Signal Inc.
    Inventors: Rajat S. Basu, Peter B. Logsdon, Leonard M. Stachura, Earl A. E. Lund
  • Patent number: 5215593
    Abstract: A substrate having a small-diameter hole is taken from the air and placed in a boiling vapor and/or boiling liquid in a first treatment tank of a vessel having a boiling heater, whereupon the pressure of the air in the small-diameter hole exceeds atmospheric pressure by an amount equivalent to the partial pressure of the air in the hole. Accordingly, the air cannot remain in the hole but is instead expelled to the outside. As a result, the interior of the microhole is replaced entirely by the boiling vapor and/or boiling liquid. Next, without being brought into contact with the external air, the substrate is contacted with a non-boiling liquid inside a second treatment tank, thereby preventing external gas from flowing back into the small-diameter. The non-boiling liquid and the boiling vapor and/or boiling liquid are soluble in each other. As a result, the two are unified and introduced to the small-diameter hole in the form of a liquid.
    Type: Grant
    Filed: April 25, 1991
    Date of Patent: June 1, 1993
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shigenobu Nojo, Hideho Inagawa, Tohru Ohsaka
  • Patent number: 5213707
    Abstract: Azeotrope-like compositions of 1-chloro-3,3,3-trifluoropropane and a mono- or dichlorinated C.sub.1 or C.sub.3 alkane have been discovered which are useful in a variety of applications including industrial cleaning, blowing agent and aerosol applications.
    Type: Grant
    Filed: November 26, 1991
    Date of Patent: May 25, 1993
    Assignee: Allied-Signal Inc.
    Inventors: Ellen L. Swan, Richard M. Hollister, Rajat S. Basu
  • Patent number: 5211866
    Abstract: Azeotrope-like compositions of 1-chloro-3,3,3-trifluoropropane and isopropanol have been discovered which are useful in a variety of applications including industrial cleaning, refrigerant and aerosol applications.
    Type: Grant
    Filed: November 26, 1991
    Date of Patent: May 18, 1993
    Assignee: Allied-Signal Inc.
    Inventors: Ellen L. Swan, Rajat S. Basu, Richard M. Hollister
  • Patent number: 5208073
    Abstract: In this invention, a method of manufacturing a colored metallic sheet comprises steps of holding a surface to be painted of metallic plates 10 in a fluorine- or fluoride-containing atmosphere in a heated condition to form a fluorided layer on the surface to be painted, removing the formed fluorided layer on the surface just before painting the surface to expose a metallic base, and painting the exposed metallic base surface.
    Type: Grant
    Filed: October 2, 1991
    Date of Patent: May 4, 1993
    Assignee: Daidousanso Co., Ltd.
    Inventor: Akira Yoshino
  • Patent number: 5207836
    Abstract: An improved process is disclosed for the removal of deposits such as tungsten or tungsten silicide from a susceptor in a vacuum deposition chamber without leaving fluorine residues by first flowing a gaseous source of fluorine into a vacuum deposition chamber and igniting a plasma in the chamber while the gaseous source of fluorine is flowing therein to remove the depositions followed by flowing a gaseous source of hydrogen into the chamber and maintaining a plasma in the chamber during the flow of the gaseous source of hydrogen to remove any fluorine residues from the chamber.
    Type: Grant
    Filed: June 3, 1992
    Date of Patent: May 4, 1993
    Assignee: Applied Materials, Inc.
    Inventor: Mei Chang
  • Patent number: 5204026
    Abstract: A cleaning solvent having an extended shelf life includes ethylene dipropionate, and at least one alicyclic carbonate, preferably propylene carbonate, with or without other additives. Typically additives include triethanolamine (TEA) and N-methyl-2-pyrrolidone (NMP). The solvents may be diluted with water for cleaning tasks where control of corrosion is not an important consideration.
    Type: Grant
    Filed: January 23, 1992
    Date of Patent: April 20, 1993
    Assignee: The Boeing Company
    Inventor: Patrisha A. Doscher-Good
  • Patent number: 5201960
    Abstract: A method for removing adherent matrices, such as highly cross-linked photoresist layers, from substrates, such as semiconductor wafers, comprises exposing the matrix to a vapor phase solvent and allowing the solvent to penetrate the matrix. After penetration, the vapor is condensed and then revaporized in order to promote fragmentation of the matrix and facilitate removal. Optionally, the matrix may be treated with a pre-swelling solvent and the resulting fragments removed by washing with a liquid or vapor solvent for the fragmented matrix material.
    Type: Grant
    Filed: February 26, 1992
    Date of Patent: April 13, 1993
    Assignee: Applied Photonics Research, Inc.
    Inventor: Vladimir Starov