Patents by Inventor Hironori Daikoku

Hironori Daikoku 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).

  • Patent number: 10968535
    Abstract: 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: Grant
    Filed: April 5, 2018
    Date of Patent: April 6, 2021
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Masayoshi Doi, Hironori Daikoku, Motohisa Kado, Tomohiro Sato, Kazuaki Seki, Kazuhiko Kusunoki, Yutaka Kishida
  • Publication number: 20210020938
    Abstract: A main object of the present disclosure is to provide an active material wherein an expansion upon intercalation of a metal ion such as a Li ion is suppressed. The present disclosure achieves the object by providing an active material comprising a silicon clathrate type crystal phase, and the active material includes a Na element, a Si element and a M element that is a metal element with an ion radius larger than the Si element, and a proportion of the M element to a total of the Si element and the M element is 0.1 atm % or more and 5 atm % or less.
    Type: Application
    Filed: June 19, 2020
    Publication date: January 21, 2021
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Hiroyuki YAMAGUCHI, Hironori DAIKOKU, Jun YOSHIDA, Kazuhiro SUZUKI, Mitsutoshi OTAKI
  • Patent number: 10640885
    Abstract: 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: Grant
    Filed: April 5, 2018
    Date of Patent: May 5, 2020
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Masayoshi Doi, Hironori Daikoku, Motohisa Kado, Tomohiro Sato, Kazuaki Seki, Kazuhiko Kusunoki, Yutaka Kishida
  • Patent number: 10450671
    Abstract: Provided is a SiC single crystal that has a large growth thickness and contains no inclusions. A SiC single crystal grown by a solution process, wherein the total length M of the outer peripheral section formed by the {1-100} faces on the {0001} growth surface of the SiC single crystal, and the length P of the outer periphery of the growth surface of the SiC single crystal, satisfy the relationship M/P?0.70, and the length in the growth direction of the SiC single crystal is 2 mm or greater.
    Type: Grant
    Filed: August 27, 2014
    Date of Patent: October 22, 2019
    Assignees: TOYOTA JIDOSHA KABUSHIKI KAISHA, NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Hironori Daikoku, Motohisa Kado, Kazuhito Kamei, Kazuhiko Kusunoki
  • Patent number: 10145025
    Abstract: Provided is a method for producing a SiC single crystal which can suppress generation of SiC polycrystals. The method according to the present embodiment is in accordance with a solution growth method. The method for producing a SiC single crystal according to the present embodiment comprises a power-output increasing step, a contact step, and a growth step. In the power-output increasing step, high-frequency power output of an induction heating device is increased to crystal-growth high-frequency power output. In the contact step, a SiC seed crystal is brought into contact with a Si—C solution. The high-frequency power output of the induction heating device in the contact step is more than 80% of the crystal-growth high-frequency power output. The temperature of the Si—C solution in the contact step is less than a crystal growth temperature. In the growth step, the SiC single crystal is grown at the crystal growth temperature.
    Type: Grant
    Filed: March 16, 2016
    Date of Patent: December 4, 2018
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Kazuaki Seki, Kazuhiko Kusunoki, Kazuhito Kamei, Katsunori Danno, Hironori Daikoku, Masayoshi Doi
  • Patent number: 10119199
    Abstract: A production method according an embodiment of the present invention is to produce a SiC single crystal by a solution growth technique, and includes a formation step and a growth step. In the formation step, material of Si—C solution contained in a crucible is melted, and a Si—C solution is formed. In the growth step, a SiC seed crystal attached to a bottom end of a seed shaft is brought into contact with the Si—C solution, and a SiC single crystal is grown on a crystal growth surface of the SiC seed crystal. In the growth step, while a temperature of the Si—C solution is being raised, the SiC single crystal is grown. The SiC single crystal production method according to the embodiment facilitates production of a SiC single crystal of a desired polytype.
    Type: Grant
    Filed: March 17, 2016
    Date of Patent: November 6, 2018
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Kazuaki Seki, Kazuhito Kamei, Kazuhiko Kusunoki, Katsunori Danno, Hironori Daikoku, Masayoshi Doi
  • Publication number: 20180312996
    Abstract: 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: Application
    Filed: April 5, 2018
    Publication date: November 1, 2018
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Masayoshi DOI, Hironori DAIKOKU, Motohisa KADO, Tomohiro SATO, Kazuaki SEKI, Kazuhiko KUSUNOKI, Yutaka KISHIDA
  • Patent number: 10100432
    Abstract: An apparatus (10) for producing an SiC single crystal is used in the solution growth includes a seed shaft (28) and a crucible (14). The seed shaft (28) has a lower end surface (28S) to which an SiC seed crystal (32) is to be attached. The crucible (14) holds an Si—C solution (15). The seed shaft (28) includes a cylinder part (28A), a bottom part (28B), and a low heat conductive member (28C). The bottom part (28B) is located at the lower end of the cylinder part (28A) and has the lower end surface (28S). The low heat conductive member (28C) is arranged on the upper surface of the bottom part (28B) and has a thermal conductivity lower than that of the bottom part (28B). This production apparatus can make the temperature within the crystal growth surface of the SiC seed crystal less liable to vary.
    Type: Grant
    Filed: July 10, 2013
    Date of Patent: October 16, 2018
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Nobuhiro Okada, Kazuhito Kamei, Kazuhiko Kusunoki, Nobuyoshi Yashiro, Koji Moriguchi, Hironori Daikoku, Motohisa Kado, Hidemitsu Sakamoto
  • Patent number: 10081883
    Abstract: Provided is a method for producing a SiC single crystal having a concave growth surface and containing no inclusions, even when conducting large diameter crystal growth. This is achieved by 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 the temperature decreases from the interior toward the liquid level, to cause crystal growth of a SiC single crystal, wherein the seed crystal holding shaft has a shaft portion and a seed crystal holding portion at the bottom end of the shaft portion, and the ratio of the diameter D1 of the shaft portion to the diameter D2 of the seed crystal holding portion (D1/D2) is no greater than 0.28.
    Type: Grant
    Filed: January 6, 2017
    Date of Patent: September 25, 2018
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Motohisa Kado, Hironori Daikoku, Kazuhiko Kusunoki, Kazuaki Seki
  • Publication number: 20180112329
    Abstract: Provided is a method for producing a SiC single crystal which can suppress generation of SiC polycrystals. The method according to the present embodiment is in accordance with a solution growth method. The method for producing a SiC single crystal according to the present embodiment comprises a power-output increasing step, a contact step, and a growth step. In the power-output increasing step, high-frequency power output of an induction heating device is increased to crystal-growth high-frequency power output. In the contact step, a SiC seed crystal is brought into contact with a Si—C solution. The high-frequency power output of the induction heating device in the contact step is more than 80% of the crystal-growth high-frequency power output. The temperature of the Si—C solution in the contact step is less than a crystal growth temperature. In the growth step, the SiC single crystal is grown at the crystal growth temperature.
    Type: Application
    Filed: March 16, 2016
    Publication date: April 26, 2018
    Inventors: Kazuaki SEKI, Kazuhiko KUSUNOKI, Kazuhito KAMEI, Katsunori DANNO, Hironori DAIKOKU, Masayoshi DOI
  • Publication number: 20180112328
    Abstract: A production method according an embodiment of the present invention is to produce a SiC single crystal by a solution growth technique, and includes a formation step and a growth step. In the formation step, material of Si—C solution contained in a crucible is melted, and a Si—C solution is formed. In the growth step, a SiC seed crystal attached to a bottom end of a seed shaft is brought into contact with the Si—C solution, and a SiC single crystal is grown on a crystal growth surface of the SiC seed crystal. In the growth step, while a temperature of the Si—C solution is being raised, the SiC single crystal is grown. The SiC single crystal production method according to the embodiment facilitates production of a SiC single crystal of a desired polytype.
    Type: Application
    Filed: March 17, 2016
    Publication date: April 26, 2018
    Inventors: Kazuaki SEKI, Kazuhito KAMEI, Kazuhiko KUSUNOKI, Katsunori DANNO, Hironori DAIKOKU, Masayoshi DOI
  • Patent number: 9920449
    Abstract: The production method of an SiC single crystal is a production method of an SiC single crystal by a solution growth process. The production method includes a contact step A, a contact step B, and a growth step. In the contact step A, a partial region of the principal surface is brought into contact with a stored Si—C solution. In the contact step B, a contact region between the principal surface and the stored Si—C solution expands, due to a wetting phenomenon, starting from an initial contact region which is the partial region brought into contact in the contact step A. In the growth step, an SiC single crystal is grown on the principal surface which is in contact with the stored Si—C solution.
    Type: Grant
    Filed: February 12, 2015
    Date of Patent: March 20, 2018
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Kazuhiko Kusunoki, Kazuhito Kamei, Hironori Daikoku, Hidemitsu Sakamoto
  • Patent number: 9896778
    Abstract: An apparatus for producing SiC single crystals where the quality of the SiC single crystals is improved, and a production method using such an apparatus are provided. The apparatus for producing SiC single crystals according to an embodiment of the present invention is employed to produce an SiC single crystal by the solution growth method. The production apparatus includes a crucible and a support shaft. The crucible accommodates an Si—C solution. The support shaft supports the crucible. The support shaft includes a heat removing portion for removing heat from a bottom portion of the crucible. The heat removing portion includes one of (a) a contact portion having a thermal conductivity not less than that of the bottom portion and contacting at least a portion of the bottom portion and (b) a space adjacent to at least a portion of the contact portion or the bottom portion.
    Type: Grant
    Filed: May 19, 2014
    Date of Patent: February 20, 2018
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Kazuhito Kamei, Kazuhiko Kusunoki, Motohisa Kado, Hironori Daikoku, Hidemitsu Sakamoto
  • Patent number: 9822468
    Abstract: 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: Grant
    Filed: May 3, 2016
    Date of Patent: November 21, 2017
    Assignees: TOYOTA JIDOSHA KABUSHIKI KAISHA, NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Hironori Daikoku, Kazuhito Kamei, Kazuhiko Kusunoki, Kazuaki Seki, Yutaka Kishida
  • Publication number: 20170327968
    Abstract: Provided is a method for producing a SiC single crystal wherein a 4H—SiC single crystal is grown by minimizing generation of polytypes other than 4H. A method for producing a SiC single crystal by a solution process, wherein a seed crystal is 4H—SiC, and a (000-1) face of the seed crystal is a growth surface, wherein the method includes: setting a temperature at a center section of a region of a surface of a Si—C solution where the growth surface of the seed crystal contacts to 1900° C. or higher, and limiting a ?Tc/?Ta to 1.7 or greater, wherein the ?Tc/?Ta is a ratio of a temperature gradient ?Tc between the center section and a location 10 mm below the center section in the vertical direction, with respect to a temperature gradient ?Ta between the center section and a location 10 mm from the center section in the horizontal direction.
    Type: Application
    Filed: May 3, 2017
    Publication date: November 16, 2017
    Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Hironori DAIKOKU, Kazuhiko KUSUNOKI, Kazuaki SEKI
  • Publication number: 20170306522
    Abstract: 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: Application
    Filed: October 13, 2015
    Publication date: October 26, 2017
    Applicants: NIPPON STEEL & SUMITOMO METAL CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Kazuhito KAMEI, Yutaka KISHIDA, Kazuhiko KUSUNOKI, Hironori DAIKOKU, Masayoshi DOI
  • Publication number: 20170298533
    Abstract: 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: Application
    Filed: October 13, 2015
    Publication date: October 19, 2017
    Inventors: Kazuhiko KUSUNOKI, Kazuhito KAMEI, Kazuaki SEKI, Yutaka KISHIDA, Koji MORIGUCHI, Hiroshi KAIDO, Hironori DAIKOKU, Masayoshi DOI
  • Patent number: 9783911
    Abstract: A production apparatus is used for a solution growth method. The production apparatus includes a seed shaft and a crucible. The seed shaft has a lower end surface to which an SiC seed crystal is attached. The crucible contains an SiC solution. The crucible includes a cylindrical portion, a bottom portion, and an inner lid. The bottom portion is disposed at a lower end of the cylindrical portion. The inner lid is disposed in the cylindrical portion. The inner lid has a through hole and is positioned below a liquid surface of the SiC solution when the SiC solution is contained in the crucible.
    Type: Grant
    Filed: July 15, 2013
    Date of Patent: October 10, 2017
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Nobuyoshi Yashiro, Kazuhito Kamei, Kazuhiko Kusunoki, Nobuhiro Okada, Koji Moriguchi, Hironori Daikoku, Hidemitsu Sakamoto, Motohisa Kado
  • Patent number: 9732441
    Abstract: An apparatus for producing an SiC single crystal includes a crucible for accommodating an Si—C solution and a seed shaft having a lower end surface where an SiC seed crystal (36) would be attached. The seed shaft includes an inner pipe that extends in a height direction of the crucible and has a first passage. An outer pipe accommodates the inner pipe and constitutes a second passage between itself and the inner pipe and has a bottom portion whose lower end surface covers a lower end opening of the outer pipe. One passage of the first and second passages serves as an introduction passage where coolant gas flows downward, and the other passage serves as a discharge passage where coolant gas flows upward. A region inside the pipe that constitutes the introduction passage is to be overlapped by a region of not less than 60% of the SiC seed crystal.
    Type: Grant
    Filed: June 15, 2012
    Date of Patent: August 15, 2017
    Assignees: NIPPON STEEL & SUMITOMO METAL CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Kazuhiko Kusunoki, Kazuhito Kamei, Nobuyoshi Yashiro, Nobuhiro Okada, Hironori Daikoku, Motohisa Kado, Hidemitsu Sakamoto
  • Publication number: 20170226658
    Abstract: 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: Application
    Filed: October 7, 2015
    Publication date: August 10, 2017
    Applicants: Nippon Steel & Sumitomo Metal Corporation, Toyota Jidosha Kabushiki Kaisha
    Inventors: Yutaka KISHIDA, Kazuhito KAMEI, Hironori DAIKOKU, Masayoshi DOI