Patents by Inventor Yutaka Kishida
Yutaka Kishida 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: 10968535Abstract: A method for a SiC single crystal that allow prolonged growth to be achieved are provided. A method for producing a SiC single crystal in which a seed crystal substrate held on a seed crystal holding shaft is contacted with a Si—C solution having a temperature gradient such that a temperature of the Si—C solution decreases from an interior of the Si—C solution toward a liquid level of the Si—C solution, in a graphite crucible, to grow a SiC single crystal, wherein the method comprises the steps of: electromagnetic stirring of the Si—C solution with an induction coil to produce a flow, and heating of a lower part of the graphite crucible with a resistance heater.Type: GrantFiled: April 5, 2018Date of Patent: April 6, 2021Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Masayoshi Doi, Hironori Daikoku, Motohisa Kado, Tomohiro Sato, Kazuaki Seki, Kazuhiko Kusunoki, Yutaka Kishida
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Patent number: 10640885Abstract: A method for a SiC single crystal that allow prolonged growth to be achieved are provided. A method for producing a SiC single crystal in which a seed crystal substrate held on a seed crystal holding shaft is contacted with a Si—C solution having a temperature gradient such that a temperature of the Si—C solution decreases from an interior of the Si—C solution toward a liquid level of the Si—C solution, in a graphite crucible, to grow a SiC single crystal, wherein the method comprises the steps of: electromagnetic stirring of the Si—C solution with an induction coil to produce a flow, and heating of a lower part of the graphite crucible with a resistance heater.Type: GrantFiled: April 5, 2018Date of Patent: May 5, 2020Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Masayoshi Doi, Hironori Daikoku, Motohisa Kado, Tomohiro Sato, Kazuaki Seki, Kazuhiko Kusunoki, Yutaka Kishida
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Patent number: 10370253Abstract: Provided is a silicon refining device that is used when industrially producing silicon of high purity by vacuum melting, has a high P removal rate and thus high productivity, and is a practical device cost-wise with a simple and cheap device configuration. This silicon refining device comprises, in a decompression vessel provided with a vacuum pump, a crucible that contains a metal silicon material, a heating device that heats the crucible, and a molten metal surface thermal insulation member that covers the upper portion of silicon molten metal and has an exhaust opening with an opening area that is smaller than the silicon molten metal surface area. The molten metal surface thermal insulation member comprises a laminated insulation material with a multilayer structure in which three or more laminates are laminated at predetermined intervals from each other, and which exhibits a radiant heat insulating function based on the multilayer structure.Type: GrantFiled: March 9, 2012Date of Patent: August 6, 2019Assignee: Silicio Ferrosolar S.L.Inventors: Yutaka Kishida, Hitoshi Dohnomae
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Patent number: 10167199Abstract: Provided are: a method for manufacturing a highly pure silicon by unidirectional solidification of molten silicon, that can inexpensively and industrially easily manufacture highly pure silicon that has a low oxygen concentration and low carbon concentration and is suitable for applications such as manufacturing solar cells; highly pure silicon obtained by this method; and silicon raw material for manufacturing highly pure silicon. A method for manufacturing highly pure silicon using molten silicon containing 100 to 1000 ppmw of carbon and 0.5 to 2000 ppmw of germanium as the raw material when manufacturing highly pure silicon by unidirectionally solidifying molten silicon raw material in a casting container, the highly pure silicon obtained by this method, and the silicon raw material for manufacturing the highly pure silicon.Type: GrantFiled: March 8, 2012Date of Patent: January 1, 2019Assignee: Silicio Ferrosolar S.L.Inventors: Shinji Tokumaru, Masataka Hiyoshi, Jiro Kondo, Hitoshi Dohnomae, Yutaka Kishida, Shigeru Nakazawa, Kozo Onoue
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Publication number: 20180312996Abstract: A method for a SiC single crystal that allow prolonged growth to be achieved are provided. A method for producing a SiC single crystal in which a seed crystal substrate held on a seed crystal holding shaft is contacted with a Si—C solution having a temperature gradient such that a temperature of the Si—C solution decreases from an interior of the Si—C solution toward a liquid level of the Si—C solution, in a graphite crucible, to grow a SiC single crystal, wherein the method comprises the steps of: electromagnetic stirring of the Si—C solution with an induction coil to produce a flow, and heating of a lower part of the graphite crucible with a resistance heater.Type: ApplicationFiled: April 5, 2018Publication date: November 1, 2018Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Masayoshi DOI, Hironori DAIKOKU, Motohisa KADO, Tomohiro SATO, Kazuaki SEKI, Kazuhiko KUSUNOKI, Yutaka KISHIDA
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Patent number: 9822468Abstract: A method for producing a SiC single crystal by a solution process is provided, which allows generation of miscellaneous crystals to be reduced. Method for producing a SiC single crystal wherein a crucible has thickness Lu in horizontal direction at same height as liquid level of Si—C solution, and thickness Ld in horizontal direction at same height as bottom inner wall, Ld/Lu is 2.00 to 4.21, and thickness in horizontal direction of crucible monotonously increases between Lu and Ld from Lu toward Ld, wall thickness of crucible is 1 mm or greater, bottom thickness Lb in vertical direction of crucible is between 1 mm and 15 mm, bottom outer wall of crucible has flat section with area of 100 mm2 or greater, depth of Si—C solution from bottom inner wall is 30 mm or greater, and method includes heating and electromagnetic stirring Si—C solution with high-frequency coil.Type: GrantFiled: May 3, 2016Date of Patent: November 21, 2017Assignees: TOYOTA JIDOSHA KABUSHIKI KAISHA, NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Hironori Daikoku, Kazuhito Kamei, Kazuhiko Kusunoki, Kazuaki Seki, Yutaka Kishida
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Publication number: 20170306522Abstract: An object of the present invention is to provide a SIC single crystal production apparatus that stirs and heats a Si—C solution easily. The apparatus includes a crucible capable of containing a Si—C solution, a seed shaft, and an induction heater. The crucible includes a tubular portion and a bottom portion. The tubular portion includes an outer peripheral surface and an inner peripheral surface. The bottom portion is disposed at a lower end of the tubular portion. The bottom portion defines an inner bottom surface of the crucible. The outer peripheral surface includes a groove extending in a direction crossing the circumferential direction of the tubular portion.Type: ApplicationFiled: October 13, 2015Publication date: October 26, 2017Applicants: NIPPON STEEL & SUMITOMO METAL CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Kazuhito KAMEI, Yutaka KISHIDA, Kazuhiko KUSUNOKI, Hironori DAIKOKU, Masayoshi DOI
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Publication number: 20170298533Abstract: The provided by the disclosure is a SiC single crystal production method permitting suppression of temperature variation of a Si—C solution even in a case of long-time crystal growth. The SiC single crystal production method includes: a preparation step of preparing a production apparatus including a crucible, a seed shaft, and an internal lid; a formation step of heating the material in the crucible to form the Si—C solution; a growth step of bringing the seed crystal into contact with the Si—C solution to produce the Si—C single crystal on the seed crystal; an internal lid adjustment step of vertically moving one of the internal lid and the crucible relative to the other during the growth step to keep an amount of variation in vertical distance between the internal lid and the Si—C solution within a first reference range.Type: ApplicationFiled: October 13, 2015Publication date: October 19, 2017Inventors: Kazuhiko KUSUNOKI, Kazuhito KAMEI, Kazuaki SEKI, Yutaka KISHIDA, Koji MORIGUCHI, Hiroshi KAIDO, Hironori DAIKOKU, Masayoshi DOI
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Publication number: 20170283982Abstract: A production method according to an embodiment includes a formation step (S1), a first growth step (S2), a recovery step (S3), and a second growth step (S4). In the formation step (S1), a Si—C solution containing Si, Al and C is formed in a crucible. In the first growth step (S2), a seed shaft is moved down to bring a SiC seed crystal attached to the bottom edge of the seed shaft onto contact with the Si—C solution, and thereafter, an Al-doped p-type SiC single crystal is grown on the SiC seed crystal. After the first growth step (S2), the Al concentration in the Si—C solution is increased in the recovery step (S3). After the recovery step (S3), the Al-doped p-type SiC single crystal is further grown in the second growth step (S4).Type: ApplicationFiled: August 31, 2015Publication date: October 5, 2017Inventors: Kazuhiko KUSUNOKI, Kazuhito KAMEI, Kazuaki SEKI, Yutaka KISHIDA, Koji MORIGUCHI, Hiroshi KAIDO
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Publication number: 20170226658Abstract: A method and apparatus for manufacturing an SiC single crystal includes a graphite crucible for receiving an SiC solution with first and second induction heating coils wound around it. The first induction heating coil is located higher than the surface of the SiC solution. The second induction heating coil is located lower than the first induction heating coil. A power supply supplies a first alternating current to the first induction heating coil and supplies, to the second induction heating coil, a second alternating current having the same frequency as the first alternating current and flowing in the direction opposite to that of the first alternating current. The distance between the surface of the SiC solution and the position in the portion of the side wall of the crucible in contact with the SiC solution with the strength of a magnetic field at its maximum satisfies a predetermined equation.Type: ApplicationFiled: October 7, 2015Publication date: August 10, 2017Applicants: Nippon Steel & Sumitomo Metal Corporation, Toyota Jidosha Kabushiki KaishaInventors: Yutaka KISHIDA, Kazuhito KAMEI, Hironori DAIKOKU, Masayoshi DOI
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Publication number: 20160340794Abstract: A method for producing a SiC single crystal by a solution process is provided, which allows generation of miscellaneous crystals to be reduced. Method for producing a SiC single crystal wherein a crucible has thickness Lu in horizontal direction at same height as liquid level of Si—C solution, and thickness Ld in horizontal direction at same height as bottom inner wall, Ld/Lu is 2.00 to 4.21, and thickness in horizontal direction of crucible monotonously increases between Lu and Ld from Lu toward Ld, wall thickness of crucible is 1 mm or greater, bottom thickness Lb in vertical direction of crucible is between 1 mm and 15 mm, bottom outer wall of crucible has flat section with area of 100 mm2 or greater, depth of Si—C solution from bottom inner wall is 30 mm or greater, and method includes heating and electromagnetic stirring Si—C solution with high-frequency coil.Type: ApplicationFiled: May 3, 2016Publication date: November 24, 2016Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Hironori DAIKOKU, Kazuhito KAMEI, Kazuhiko KUSUNOKI, Kazuaki SEKI, Yutaka KISHIDA
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Publication number: 20150082942Abstract: An objective of the present invention is, in refining a metal or a semiconductor melt, without impairing refining efficiency, to alleviate wear and tear commensurate with unevenness in a crucible caused by instability in melt flow, and to allow safe operation over long periods of time such that leakages from the crucible do not occur. Provided is a metal or semiconductor melt refining method, in which, by using an AC resistance heating heater as a crucible heating method, the melt is heat retained and mixed by a rotating magnetic field which is generated by the resistance heating heater.Type: ApplicationFiled: February 6, 2012Publication date: March 26, 2015Applicant: SILICIO FERROSOLAR S.L.Inventors: Yutaka Kishida, Hitoshi Dohnomae, Jiro Kondo, Kiyoshi Goto, Wataru Ohashi
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Publication number: 20150033798Abstract: Provided is a silicon refining device that is used when industrially producing silicon of high purity by vacuum melting, has a high P removal rate and thus high productivity, and is a practical device cost-wise with a simple and cheap device configuration. This silicon refining device comprises, in a decompression vessel provided with a vacuum pump, a crucible that contains a metal silicon material, a heating device that heats the crucible, and a molten metal surface thermal insulation member that covers the upper portion of silicon molten metal and has an exhaust opening with an opening area that is smaller than the silicon molten metal surface area. The molten metal surface thermal insulation member comprises a laminated insulation material with a multilayer structure in which three or more laminates are laminated at predetermined intervals from each other, and which exhibits a radiant heat insulating function based on the multilayer structure.Type: ApplicationFiled: March 9, 2012Publication date: February 5, 2015Applicant: SILICIO FERROSOLAR S.L.Inventors: Yutaka Kishida, Hitoshi Dohnomae
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Publication number: 20150028268Abstract: Provided are a method for manufacturing a highly pure silicon by unidirectional solidification of molten silicon, that can inexpensively and industrially easily manufacture highly pure silicon that has a low oxygen concentration and low carbon concentration and is suitable for applications such as manufacturing solar cells; highly pure silicon obtained by this method and silicon raw material for manufacturing highly pure silicon. A method for manufacturing highly pure silicon using molten silicon containing 100 to 1000 ppmw of carbon and 0.5 to 2000 ppmw of germanium as the raw material when manufacturing highly pure silicon by unidirectionally solidifying molten silicon raw material in a casting container, the highly pure silicon obtained by this method, and the silicon raw material for manufacturing the highly pure silicon.Type: ApplicationFiled: March 8, 2012Publication date: January 29, 2015Applicant: SILICIO FERROSOLAR S.L.Inventors: Shinji Tokumaru, Masataka HIiyoshi, Jiro Kondo, Hitoshi Dohnomae, Yutaka Kishida, Shigeru Nakazawa, Kozo Onoue
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Patent number: 7582160Abstract: In silicon single crystal growth by the Czochralski method using a quartz crucible, a silicon single crystals with a uniform distribution of oxygen concentration can be produced in high yield without being affected by changes of crystal diameter and initial amount of melt feedstock. The oxygen concentration is adjusted by estimating oxygen concentration during growth on the basis of a relationship among three parameters: crucible rotation rate (?), crucible temperature (T), and the ratio (?) of contact area of molten silicon with the inner wall of the crucible and with atmospheric gas, and by associating the temperature (T) with the ratio (?) by the function 1/?×Exp(?E/T) where E is the dissolution energy (E) of quartz into molten silicon to control at least one of the rotation rate (?) and temperature (T) to conform the estimated oxygen concentration to a target concentration.Type: GrantFiled: June 13, 2006Date of Patent: September 1, 2009Assignee: Siltronic AGInventors: Yutaka Kishida, Seiki Takebayashi, Teruyuki Tamaki
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Patent number: 7195668Abstract: A crucible for the growth of single crystals by the Czochralski method which can enhance the productivity, yield and quality of crystal and a single crystal growing method, wherein the crucible has an inner bottom surface, the profile of which has at least one raised portion symmetrical about the rotary axis of the crucible wherein the periphery of the raised portion is positioned at a distance of from 0.4 to 1.2 times the radius of crystal to be grown from the rotary axis and the height of the raised portion is generally not smaller than 7% and greater than 100% of the radius of crystal to be grown.Type: GrantFiled: December 22, 2004Date of Patent: March 27, 2007Assignee: Siltronic AGInventors: Yutaka Kishida, Teruyuki Tamaki
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Publication number: 20060283378Abstract: In silicon single crystal growth by the Czochralski method using a quartz crucible, a silicon single crystals with a uniform distribution of oxygen concentration can be produced in high yield without being affected by changes of crystal diameter and initial amount of melt feedstock. The oxygen concentration is adjusted by estimating oxygen concentration during growth on the basis of a relationship among three parameters: crucible rotation rate (?), crucible temperature (T), and the ratio (?) of contact area of molten silicon with the inner wall of the crucible and with atmospheric gas, and by associating the temperature (T) with the ratio (?) by the function 1/?×Exp(?E/T) where E is the dissolution energy (E) of quartz into molten silicon to control at least one of the rotation rate (?) and temperature (T) to conform the estimated oxygen concentration to a target concentration.Type: ApplicationFiled: June 13, 2006Publication date: December 21, 2006Applicant: Siltronic AGInventors: Yutaka Kishida, Seiki Takebayashi, Teruyuki Tamaki
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Publication number: 20050139153Abstract: A crucible for the growth of single crystals by the Czochralski method which can enhance the productivity, yield and quality of crystal and a single crystal growing method, wherein the crucible has an inner bottom surface, the profile of which has at least one raised portion symmetrical about the rotary axis of the crucible wherein the periphery of the raised portion is positioned at a distance of from 0.4 to 1.2 times the radius of crystal to be grown from the rotary axis and the height of the raised portion is generally not smaller than 7% and greater than 100% of the radius of crystal to be grown.Type: ApplicationFiled: December 22, 2004Publication date: June 30, 2005Inventors: Yutaka Kishida, Teruyuki Tamaki
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Patent number: 6899759Abstract: A single crystal production method based on the Czochralski method comprises controlling a number of crucible rotations and crystal rotations so that a number of vibrations for driving a melt, determined on the basis of the number of crucible and crystal rotations during a single crystal growing procedure, is outside a range from 95% to 105% of a number of sloshing resonance vibrations of the melt. In another embodiment, the method comprises controlling a number of rotations of a crystal and crucible, so that when a number of vibrations for driving a melt, determined by the number of crucible and crystal rotations during a single crystal growing procedure, is within a range from 95% to 105% of a number of sloshing resonance vibrations of the melt, the number of vibrations of the melt due to sloshing does not exceed 2000 times during a period when the number of vibrations is within that range.Type: GrantFiled: October 30, 2002Date of Patent: May 31, 2005Assignee: Siltronic AGInventors: Yutaka Kishida, Teruyuki Tamaki, Seiki Takebayashi, Wataru Ohashi
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Patent number: 6793902Abstract: In the manufacture of a silicon single crystal by the Czochralski method, there is provided a seed crystal for use in the production of the silicon single crystal. This seed crystal is capable of preventing creation of a dislocation occurring during the immersion of the seed crystal in the molten silicon and withstanding the load of a silicon single crystal of great weight as well. There is also a method for the production of the seed crystal and a method for the production of a silicon single crystal which enables the ratio of elimination of dislocation to be increased.Type: GrantFiled: December 11, 2002Date of Patent: September 21, 2004Assignee: Siltronic AGInventors: Masahiro Tanaka, Yutaka Kishida, Teruyuki Tamaki, Hideo Kato, Seiki Takebayashi