Patents by Inventor Michihiko Yanagisawa
Michihiko Yanagisawa has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 11504669Abstract: The present invention provides an energy-efficient method and apparatus that can achieve exhaust gas abatement with a minimum use of diluent nitrogen gas. More specifically, the present invention is directed to a method and apparatus for exhaust gas abatement under reduced pressure, in which an exhaust gas supplied from an exhaust gas source via a vacuum pump is decomposed by heat of a high-temperature plasma under a reduced pressure.Type: GrantFiled: April 20, 2018Date of Patent: November 22, 2022Assignee: KANKEN TECHNO CO., LTD.Inventors: Michihiko Yanagisawa, Tsutomu Tsukada, Hiroshi Imamura
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Publication number: 20200122085Abstract: An apparatus for exhaust gas abatement under reduced pressure includes a reaction tube having, in an interior thereof, an exhaust gas treatment space in which an exhaust gas supplied from an exhaust gas source via a vacuum pump is heated by an electric heater or excited by a plasma for decomposition and/or reaction treatment. The apparatus also includes a downstream vacuum pump connected to an exhaust gas outlet located downstream of the reaction tube to reduce a pressure in a region located downstream of an outlet of the vacuum pump and including the interior of the reaction tube. The downstream vacuum pump is a water-sealed pump. The apparatus further includes a water-washing unit for washing a downstream end of an exhaust gas flow path in the reaction tube with washing water. The washing water supplied by the water-washing unit is reused as seal water for the downstream vacuum pump.Type: ApplicationFiled: May 2, 2018Publication date: April 23, 2020Inventors: Masashi MAEDA, Akihisa YOSHIDA, Michihiko YANAGISAWA, Tsutomu TSUKADA, Hiroshi IMAMURA
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Patent number: 10617997Abstract: An apparatus for exhaust gas abatement under reduced pressure includes a reaction tube having, in an interior thereof, an exhaust gas treatment space in which an exhaust gas supplied from an exhaust gas source via a vacuum pump is heated by an electric heater or excited by a plasma for decomposition and/or reaction treatment. The apparatus also includes a downstream vacuum pump connected to an exhaust gas outlet located downstream of the reaction tube to reduce a pressure in a region located downstream of an outlet of the vacuum pump and including the interior of the reaction tube. The downstream vacuum pump is a water-sealed pump. The apparatus further includes a water-washing unit for washing a downstream end of an exhaust gas flow path in the reaction tube with washing water. The washing water supplied by the water-washing unit is reused as seal water for the downstream vacuum pump.Type: GrantFiled: May 2, 2018Date of Patent: April 14, 2020Assignee: KANKEN TECHNO CO., LTD.Inventors: Masashi Maeda, Akihisa Yoshida, Michihiko Yanagisawa, Tsutomu Tsukada, Hiroshi Imamura
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Publication number: 20200038805Abstract: The present invention provides an energy-efficient method and apparatus that can achieve exhaust gas abatement with a minimum use of diluent nitrogen gas. More specifically, the present invention is directed to a method and apparatus for exhaust gas abatement under reduced pressure, in which an exhaust gas supplied from an exhaust gas source via a vacuum pump is decomposed by heat of a high-temperature plasma under a reduced pressure.Type: ApplicationFiled: April 20, 2018Publication date: February 6, 2020Inventors: Michihiko YANAGISAWA, Tsutomu TSUKADA, Hiroshi IMAMURA
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Publication number: 20200033000Abstract: The present invention provides an energy-efficient method and apparatus that can achieve exhaust gas abatement with a minimum use of diluent nitrogen gas. More specifically, the present invention is directed to a method and apparatus for exhaust gas abatement under reduced pressure, in which an exhaust gas supplied from an exhaust gas source through a vacuum pump is decomposed by combustion heat of a flame under a reduced pressure.Type: ApplicationFiled: April 10, 2018Publication date: January 30, 2020Inventors: Michihiko YANAGISAWA, Tsutomu TSUKADA, Hiroshi IMAMURA
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Patent number: 7094355Abstract: This invention provides a local dry etching method comprising the step of removing an oxide film formed on the surface of a semiconductor water before unevenness on the semiconductor wafer is removed by scanning the surface of the semiconductor wafer at a controlled relative speed with a nozzle for applying a flow of activated species gas to the surface of the semiconductor wafer. The removal of this oxide film is carried out by widening an etching profile and a scan pitch and making the nozzle speed constant, and then flattening is carried out in the same local dry etching apparatus. For flattening, the nozzle speed is changed for each area according to initial unevenness.Type: GrantFiled: July 22, 2003Date of Patent: August 22, 2006Assignee: Speedfam Co., Ltd.Inventors: Michihiko Yanagisawa, Tadayoshi Okuya
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Patent number: 7005032Abstract: To resolve a problem that an etching rate profile is changed by a position of a nozzle relative to a semiconductor wafer and accordingly, at a vicinity of an outer edge of the semiconductor wafer, an accurate machining result is difficult to achieve, gas including activated species produced by plasma is blown from a nozzle locally to a surface of the semiconductor wafer W supported on a wafer table concentrically therewith to thereby remove unevenness on the surface of the semiconductor wafer. In this case, the wafer table is provided with a radius larger than a radius of the semiconductor wafer supported thereby by an outstretched portion to thereby prevent an outer edge from being removed excessively by reflected gas.Type: GrantFiled: March 18, 2002Date of Patent: February 28, 2006Assignee: Speedfam Co., Ltd.Inventors: Michihiko Yanagisawa, Kazuyuki Tsuruoka, Chikai Tanaka
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Patent number: 6908566Abstract: In a local dry etching method, position-thickness data of a semiconductor wafer is previously obtained by measuring the wafer surface, components of position-thickness data shorter than a predetermined spatial wavelength are cut off by filtering and nozzle-wafer relative speed for planarizing the surface is calculated using the filtered data.Type: GrantFiled: April 21, 2003Date of Patent: June 21, 2005Assignee: Speedfam Co., Ltd.Inventors: Michihiko Yanagisawa, Kazuyuki Tsuruoka
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Patent number: 6875701Abstract: To remove nanotopography (unevenness of wavelength: 0.2 mm through 20 mm, wave height: 1 through several hundreds nm) which has already been produced on a surface of a semiconductor wafer which has been regarded as impossible to remove conventionally, a half value width of an etching profile of activated species gas is set to fall in a range equal to or smaller than a wavelength a of nanotopography and equal to or larger than a half thereof. Based on previously measured data of nanotopography, moving speed and locus of injected activated species gas along a surface of a semiconductor wafer are calculated and controlled.Type: GrantFiled: February 5, 2002Date of Patent: April 5, 2005Assignee: Speedfam Co., Ltd.Inventors: Michihiko Yanagisawa, Tadayoshi Okuya
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Publication number: 20040142571Abstract: This invention provides a local dry etching method comprising the step of removing an oxide film formed on the surface of a semiconductor water before unevenness on the semiconductor wafer is removed by scanning the surface of the semiconductor wafer at a controlled relative speed with a nozzle for applying a flow of activated species gas to the surface of the semiconductor wafer. The removal of this oxide film is carried out by widening an etching profile and a scan pitch and making the nozzle speed constant, and then flattening is carried out in the same local dry etching apparatus. For flattening, the nozzle speed is changed for each area according to initial unevenness.Type: ApplicationFiled: July 22, 2003Publication date: July 22, 2004Applicant: Speedfam Co., Ltd.Inventors: Michihiko Yanagisawa, Tadayoshi Okuya
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Publication number: 20040063329Abstract: A local dry etching method for a SOI wafer capable of flattening an active silicon layer to a layer thickness of a target at a high throughput and to a required accuracy by using a multi-step local dry etching apparatus wherein the apparatus comprises first and second vacuum chambers, a small diameter nozzle, a large diameter nozzle of a diameter larger than that of the small diameter nozzle, an activated species gas generator for generating activated species gases to be blown out of each of the nozzles, each of feeding devices disposed in each of the vacuum chambers for providing a relative speed between the SOI wafer and each of the nozzles to conduct scanning and transportation device, in which the active silicon layer of the SOI waver is etched in the first vacuum chamber to remove the surface unevenness and the active silicon layer is etched to a required layer thickness in the second vacuum chamber.Type: ApplicationFiled: September 29, 2003Publication date: April 1, 2004Applicant: Speedfam Co., Ltd.Inventors: Michihiko Yanagisawa, Kazuyuki Tsuruoka, Yasuhiro Horiike
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Patent number: 6649528Abstract: In a local dry etching method of the invention, a surface of a representative wafer sampled from a lot is test etched, each wafer of which is sliced from the same ingot, and initial data of recesses and projections of which is previously known, recesses and projections of the representative wafer is measured after test etched, an etching profile is derived from the initial data and measured data and then respective wafer surfaces of the lot are etched in condition calculated by using at least the derived etching profile.Type: GrantFiled: May 15, 2002Date of Patent: November 18, 2003Assignee: Speedfam Co., Ltd.Inventors: Michihiko Yanagisawa, Tadayoshi Okuya
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Publication number: 20030199168Abstract: In a local dry etching method, position-thickness data of a semiconductor wafer is previously obtained by measuring the wafer surface, components of position-thickness data shorter than a predetermined spatial wavelength are cut off by filtering and nozzle-wafer relative speed for planarizing the surface is calculated using the filtered data.Type: ApplicationFiled: April 21, 2003Publication date: October 23, 2003Applicant: Speedfam Co., Ltd.Inventors: Michihiko Yanagisawa, Kazuyuki Tsuruoka
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Patent number: 6496748Abstract: A wafer flattening process designed to flatten the entire surface of the wafer including the outer rim of the wafer by inserting dummy data corresponding to the data of the outer rim of the wafer in the data of the outside of the wafer, and a storage medium for the same. An area S is set at an outside position exactly an etching radius r from an outer rim Wc of the wafer Wc ahd the nozzle relative speed at the position-speed data D of points P4-1 to P4-3 closest to an imaginary line L passing through the point P4 inside the area S near the outer rim Wc is set to be the same as the nozzle relative speed of the position-speed data D of the point P4. Due to this, the nozzle spraying the activated species gas G moves as if along the imaginary line L and the portion of the point P4 is etched flat by superposition of the activated species gas G of the nozzle passing through the points P4-1 to P4-3, the point P4, and the point P6.Type: GrantFiled: January 21, 1999Date of Patent: December 17, 2002Assignees: SpeedFam Co., Ltd.Inventors: Michihiko Yanagisawa, Shinya Iida, Yasuhiro Horiike
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Publication number: 20020173149Abstract: In a local dry etching method of the invention, a surface of a representative wafer sampled from a lot is test etched, each wafer of which is sliced from the same ingot, and initial data of recesses and projections of which is previously known, recesses and projections of the representative wafer is measured after test etched, an etching profile is derived from the initial data and measured data and then respective wafer surfaces of the lot are etched in condition calculated by using at least the derived etching profile.Type: ApplicationFiled: May 15, 2002Publication date: November 21, 2002Applicant: SPEEDFAM Co., Ltd.Inventors: Michihiko Yanagisawa, Tadayoshi Okuya
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Publication number: 20020144781Abstract: To improve a problem that according to a conventional technology, an accurate planarization is not achieved since an etching rate profile is assumed to be the same regardless of a position of a nozzle relative to a semiconductor wafer, since the etching rate profile is deformed by being influenced by a distance &egr;, a degree of deformation of the etching rate profile is previously calculated for respective position (distance &egr;) of a nozzle and an etching rate calculated thereby is used in calculating nozzle speed at a vicinity of an outer edge.Type: ApplicationFiled: February 6, 2002Publication date: October 10, 2002Inventors: Michihiko Yanagisawa, Chikai Tanaka
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Publication number: 20020139482Abstract: To resolve a problem that an etching rate profile is changed by a position of a nozzle relative to a semiconductor wafer and accordingly, at a vicinity of an outer edge of the semiconductor wafer, an accurate machining result is difficult to achieve, gas including activated species produced by plasma is blown from a nozzle locally to a surface of the semiconductor wafer W supported on a wafer table concentrically therewith to thereby remove unevenness on the surface of the semiconductor wafer. In this case, the wafer table is provided with a radius larger than a radius of the semiconductor wafer supported thereby by an outstretched portion to thereby prevent an outer edge from being removed excessively by reflected gas.Type: ApplicationFiled: March 18, 2002Publication date: October 3, 2002Inventors: Michihiko Yanagisawa, Kazuyuki Tsuruoka, Chikai Tanaka
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Patent number: 6451217Abstract: A wafer etching method wherein hydrogen gas, ammonia gas or mixed gas containing one of these gases is added to sulfur hexafluoride gas to suppress the occurrence of white turbidity on the surface of the wafer at the time of etching and to enable high quality mirror polishing of the wafer. In one embodiment, a mixed gas obtained by mixing SF6 gas G1 of a bomb 31 and H2 gas G2 of a bomb 32 in a predetermined ratio is fed to a discharge tube 2 and a microwave M is generated from a microwave oscillator 4 to cause plasma discharge. Further, the entire surface of the silicon wafer W can be flattened by locally etching the surface of the silicon wafer W by an activated species gas G sprayed from the nozzle portion 20.Type: GrantFiled: February 28, 2000Date of Patent: September 17, 2002Assignees: SpeedFam-IPEC Co., Ltd.Inventors: Michihiko Yanagisawa, Chikai Tanaka, Shinya Iida, Yasuhiro Horiike
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Patent number: 6432824Abstract: In the semiconductor wafer manufacturing method of the present invention, a deteriorated layer on the surface of a semiconductor wafer which has been made flat by lapping or polishing is removed by the following dry etching. Plasma which contains a neutral active species is generated within a discharge tube. The neutral active species is separated from the plasma thus generated and is then conveyed to an orifice side of a nozzle portion of the discharge tube. The orifice is opposed to the wafer surface and the nozzle portion moves along the wafer surface while the neutral active species is sprayed from the nozzle orifice toward the wafer surface which is pre-heated. By such dry etching, the deteriorated layer on the wafer surface is removed without the occurrence of any etch pit.Type: GrantFiled: February 20, 2001Date of Patent: August 13, 2002Assignee: Speedfam Co., Ltd.Inventor: Michihiko Yanagisawa
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Publication number: 20020104825Abstract: To remove nanotopography (unevenness of wavelength: 0.2 mm through 20 mm, wave height: 1 through several hundreds nm) which has already been produced on a surface of a semiconductor wafer which has been regarded as impossible to remove conventionally, a half value width of an etching profile of activated species gas is set to fall in a range equal to or smaller than a wavelength a of nanotopography and equal to or larger than a half thereof. Based on previously measured data of nanotopography, moving speed and locus of injected activated species gas along a surface of a semiconductor wafer are calculated and controlled.Type: ApplicationFiled: February 5, 2002Publication date: August 8, 2002Inventors: Michihiko Yanagisawa, Tadayoshi Okuya