Patents by Inventor Hidemitsu Sakamoto

Hidemitsu Sakamoto 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: 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: 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: 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
  • Patent number: 9708734
    Abstract: The purpose of the present invention is to produce a high-quality SiC single crystal with good reproducibility while avoiding the fluctuations in the solution-contacting position of a seed crystal among production operations. A method for producing a SiC single crystal by bringing a SiC seed crystal supported by a supporting bar into contact with a solution that has been heated by high-frequency induction to thereby grow the SiC single crystal, wherein the supporting bar is born down while applying a magnetic field to the solution to thereby bring the SiC seed crystal into contact with the solution, and subsequently the application of the magnetic field is halted to grow the SiC single crystal.
    Type: Grant
    Filed: November 11, 2013
    Date of Patent: July 18, 2017
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Hironori Daikoku, Hidemitsu Sakamoto, Motohisa Kado, Kazuhiko Kusunoki
  • Patent number: 9702056
    Abstract: A region of an SiC solution in the vicinity of an SiC seed crystal is cooled while suppressing the temperature variation in a peripheral region of the SiC solution. An apparatus includes a seed shaft and a crucible for an SiC solution. The seed shaft has a lower end surface for attachment to an SiC seed crystal. The crucible comprises a main body, an intermediate cover, and a top cover. The main body includes a first cylindrical portion and a bottom portion at a lower end portion of the first cylindrical portion. The intermediate cover is within the first cylindrical portion and above the liquid level of the SiC solution in the main body. The intermediate cover has a first through hole for the seed shaft. The top cover is disposed above the intermediate cover and has a second through hole for the seed shaft to pass through.
    Type: Grant
    Filed: June 11, 2012
    Date of Patent: July 11, 2017
    Assignees: NIPPON STEEL & SUMITOMO METAL CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Kazuhito Kamei, Kazuhiko Kusunoki, Nobuyoshi Yashiro, Nobuhiro Okada, Hironori Daikoku, Motohisa Kado, Hidemitsu Sakamoto
  • Patent number: 9617655
    Abstract: An apparatus for SIC single crystal has an induction heating control unit such that frequency f (Hz) of alternating current to the induction heating unit satisfies Formula (1); D1 (mm) is permeation depth of electromagnetic waves into a crucible side wall by the heating unit, D2 (mm) is permeation depth of electromagnetic waves into a SIC solution, T (mm) is thickness of the crucible side wall of the crucible, and R (mm) is crucible inner radius: (D1?T)×D2/R>1.5??(1) where, D1 is defined by Formula (2) and D2 by Formula (3): D1=503292×(1/(f×?c×?c))1/2??(2) D2=503292×(1/(f×?s×?s))1/2??(3); ?c is electric conductivity (S/m) of the sidewall, ?s is electric conductivity (S/m) of the SiC solution; ?c is relative permeability of the sidewall, and ?s is relative permeability of the SIC solution.
    Type: Grant
    Filed: December 26, 2011
    Date of Patent: April 11, 2017
    Assignees: NIPPON STEEL & SUMITOMO METAL CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Nobuhiro Okada, Kazuhito Kamei, Kazuhiko Kusunoki, Nobuyoshi Yashiro, Kouji Moriguchi, Hironori Daikoku, Hiroshi Suzuki, Tomokazu Ishii, Hidemitsu Sakamoto, Motohisa Kado, Yoichiro Kawai
  • Publication number: 20170009373
    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: Application
    Filed: February 12, 2015
    Publication date: January 12, 2017
    Inventors: Kazuhiko KUSUNOKI, Kazuhito KAMEI, Hironori DAIKOKU, Hidemitsu SAKAMOTO
  • Patent number: 9523156
    Abstract: Provided are: a high-quality SiC single crystal ingot that suppresses the generation of inclusions; and a production method for said SiC single crystal ingot. The present invention pertains to a SiC single crystal ingot including a seed crystal substrate and a SiC growth crystal grown using the solution method and using the seed crystal substrate as the origin thereof, the growth crystal having a recessed crystal growth surface and not including inclusions.
    Type: Grant
    Filed: May 8, 2013
    Date of Patent: December 20, 2016
    Assignees: TOYOTA JIDOSHA KABUSHIKI KAISHA, NIPPON STEEL & SUMITOMO METAL CORPORATIN
    Inventors: Motohisa Kado, Hironori Daikoku, Hidemitsu Sakamoto, Kazuhiko Kusunoki, Nobuhiro Okada
  • Patent number: 9388508
    Abstract: A manufacturing apparatus of a SiC single crystal which can suppress the generation of a polycrystal is provided. A jig (41) and a crucible (6) are accommodated in a chamber (1). A SiC solution (8) is housed in the crucible (6). The jig (41) includes a seed shaft (411) and a cover member (412). The seed shaft (411) can move up and down, and a SiC seed crystal (9) is attached to the lower surface thereof. The cover member (412) is attached to the lower end portion of the seed shaft (411). The cover member (412) is a housing which has an opening at its lower end, wherein the lower end portion of the seed shaft (411) is disposed in the cover member (412).
    Type: Grant
    Filed: December 26, 2011
    Date of Patent: July 12, 2016
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Kazuhito Kamei, Kazuhiko Kusunoki, Nobuyoshi Yashiro, Nobuhiro Okada, Motohisa Kado, Hidemitsu Sakamoto, Hironori Daikoku
  • Publication number: 20160122900
    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: Application
    Filed: May 19, 2014
    Publication date: May 5, 2016
    Applicants: NIPPON STEEL & SUMITOMO METAL CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Kazuhito KAMEI, Kazuhiko KUSUNOKI, Motohisa KADO, Hironori DAIKOKU, Hidemitsu SAKAMOTO
  • Patent number: 9322112
    Abstract: To suppress 3D or convex growth and ensure a high flatness, an apparatus for producing an SiC single crystal includes: a container which holds an SiC solution, a portion for maintaining the solution in the container at a suitable temperature, a shaft having a lower end part acting as a portion for holding an SiC seed crystal in planar contact with an overall back surface of a crystal growth face and acting as a portion for cooling the SiC seed crystal, and a portion of the holding shaft for enabling an SiC single crystal to continuously grow at the crystal growth face by maintaining the crystal growth face brought into contact with the solution, a lower end part of the shaft having a portion for obtaining a uniform in-plane temperature distribution of the crystal growth face brought into planar contact, and a method for the same.
    Type: Grant
    Filed: December 15, 2011
    Date of Patent: April 26, 2016
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Tomokazu Ishii, Hidemitsu Sakamoto, Kazuhiko Kusunoki, Kazuhito Kamei
  • Publication number: 20160053402
    Abstract: The present invention provides a method for producing a SiC single crystal, which allows improving the quality of the single crystal even when crystal growth is performed by forming a meniscus. A growth step in the production method according to the present embodiment comprises a forming step and a first maintenance step. In the forming step, a meniscus is formed between a growth interface of a SiC single crystal and a liquid surface of a Si—C solution. In the first maintenance step, the fluctuation range of the height of the meniscus is maintained within a predetermined range by moving at least one of a seed shaft and a crucible relative to the other in the height direction.
    Type: Application
    Filed: April 9, 2014
    Publication date: February 25, 2016
    Inventors: Kazuhiko KUSUNOKI, Kazuhito KAMEI, Hironori DAIKOKU, Hidemitsu SAKAMOTO, Motohisa KADO
  • Publication number: 20150299900
    Abstract: The purpose of the present invention is to produce a high-quality SiC single crystal with good reproducibility while avoiding the fluctuations in the solution-contacting position of a seed crystal among production operations. A method for producing a SiC single crystal by bringing a SiC seed crystal supported by a supporting bar into contact with a solution that has been heated by high-frequency induction to thereby grow the SiC single crystal, wherein the supporting bar is born down while applying a magnetic field to the solution to thereby bring the SiC seed crystal into contact with the solution, and subsequently the application of the magnetic field is halted to grow the SiC single crystal.
    Type: Application
    Filed: November 11, 2013
    Publication date: October 22, 2015
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Hironori DAIKOKU, Hidemitsu SAKAMOTO, Motohisa KADO, Kazuhiko KUSUNOKI
  • Publication number: 20150225871
    Abstract: A SiC single crystal production apparatus is used in production of SiC single crystals by solution growth techniques. The apparatus includes: a seed shaft having a lower end surface to which a SiC seed crystal is to be attached; a crucible that contains a Si—C solution; a stirring member that is immersed in the Si—C solution; and drive sources that cause relative rotation between the crucible and the stirring member. The lower end of the stirring member is located lower than the lower end of the SiC seed crystal attached to the lower end surface of the seed shaft.
    Type: Application
    Filed: September 2, 2013
    Publication date: August 13, 2015
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Kazuhiko Kusunoki, Kazuhito Kamei, Nobuyoshi Yashiro, Nobuhiro Okada, Koji Moriguchi, Motohisa Kado, Hironori Daikoku, Hidemitsu Sakamoto
  • Publication number: 20150225872
    Abstract: The production apparatus is used in production of single crystals by solution growth techniques. The production apparatus includes a seed shaft, a crucible, and a drive source. The seed shaft has a lower end surface to which a seed crystal is to be attached. The crucible contains a solution from which a single crystal is made. The drive source causes the crucible to rotate, and also varies the rotational speed of the crucible. The inner peripheral surface of the crucible includes a flow control surface which defines a non-circular cross-sectional shape. This single crystal production apparatus is capable of strongly stirring the solution contained in the crucible.
    Type: Application
    Filed: August 30, 2013
    Publication date: August 13, 2015
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Kazuhito Kamei, Kazuhiko Kusunoki, Nobuyoshi Yashiro, Nobuhiro Okada, Koji Moriguchi, Hironori Daikoku, Motohisa Kado, Hidemitsu Sakamoto
  • Patent number: 9080254
    Abstract: In a method of producing a SiC single crystal, the SiC single crystal is grown on a SiC seed crystal by bringing the SiC seed crystal, which is fixed at a rotatable seed crystal fixing shaft, into contact with a solution produced by dissolving carbon in melt containing silicon in a rotatable crucible. The method includes starting rotation of the seed crystal fixing shaft, and starting rotation of the crucible after a predetermined delay time (Td); then stopping the rotation of the seed crystal fixing shaft and the rotation of the crucible simultaneously; then stopping the seed crystal fixing shaft and the crucible for a predetermined stop time (Ts); and repeating a rotation/stop cycle.
    Type: Grant
    Filed: March 11, 2010
    Date of Patent: July 14, 2015
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Hidemitsu Sakamoto, Hironori Daikoku, Yasuyuki Fujiwara
  • Publication number: 20150191848
    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: Application
    Filed: July 15, 2013
    Publication date: July 9, 2015
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Nobuyoshi Yashiro, Kazuhito Kamei, Kazuhiko Kusunoki, Nobuhiro Okada, Koji Moriguchi, Hironori Daikoku, Hidemitsu Sakamoto, Motohisa Kado
  • Publication number: 20150167196
    Abstract: Provided are: a high-quality SiC single crystal ingot that suppresses the generation of inclusions; and a production method for said SiC single crystal ingot. The present invention pertains to a SiC single crystal ingot including a seed crystal substrate and a SiC growth crystal grown using the solution method and using the seed crystal substrate as the origin thereof, the growth crystal having a recessed crystal growth surface and not including inclusions.
    Type: Application
    Filed: May 8, 2013
    Publication date: June 18, 2015
    Inventors: Motohisa Kado, Hironori Daikoku, Hidemitsu Sakamoto, Kazuhiko Kusunoki, Nobuhiro Okada