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).

  • Publication number: 20150152569
    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: Application
    Filed: July 10, 2013
    Publication date: June 4, 2015
    Inventors: Nobuhiro Okada, Kazuhito Kamei, Kazuhiko Kusunoki, Nobuyoshi Yashiro, Koji Moriguchi, Hironori Daikoku, Motohia Kado, Hidemitsu Sakamoto
  • Publication number: 20140116324
    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: Application
    Filed: June 15, 2012
    Publication date: May 1, 2014
    Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Kazuhiko Kusunoki, Kazuhito Kamei, Nobuyoshi Yashiro, Nobuhiro Okada, Hironori Daikoku, Motohisa Kado, Hidemitsu Sakamoto
  • Publication number: 20130305981
    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: Application
    Filed: December 26, 2011
    Publication date: November 21, 2013
    Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Kazuhito Kamei, Kazuhiko Kusunoki, Nobuyoshi Yashiro, Nobuhiro Okada, Motohisa Kado, Hidemitsu Sakamoto, Hironori Daikoku
  • Publication number: 20130284083
    Abstract: A manufacturing apparatus for SiC single crystal has a control unit to control induction heating such that frequency f (Hz) of alternating current to be passed to the induction heating unit satisfies Formula (1); D1 (mm) is permeation depth of electromagnetic waves into a side wall of a crucible 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??(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 relative permeability of the SiC solution.
    Type: Application
    Filed: December 26, 2011
    Publication date: October 31, 2013
    Applicants: Toyota Jidosha Kabushiki Kaisha, Nippon Steel & Sumitomo Metal Corporation
    Inventors: Nobuhiro Okada, Kazuhito Kamei, Kazuhiko Kasunoki, Nobuyoshi Yashiro, Kouji Moriguchi, Hironori Daikoku, Hiroshi Suzuki, Tomokazu Ishii, Hidemitsu Sakamoto, Motohisa Kado, Yoichiro Kawai
  • Patent number: 8328937
    Abstract: A seed crystal axis used in a solution growth of single crystal production system is provided to prevent formation of polycrystals and grow a single crystal with a high growth rate. The seed crystal axis includes a seed crystal bonded to a seed crystal support member between which is interposed a laminated carbon sheet having a high thermal conductivity in a direction perpendicular to a solution surface of a solvent. The laminated carbon sheet includes a plurality of carbon thin films laminated with an adhesive or a plurality of pieces with differing lamination directions arranged in a lattice. Alternatively, a wound carbon sheet including a carbon strip wound concentrically from the center or a wound carbon sheet including a plurality of carbon strips with differing thicknesses which are wound and laminated from the center may be provided.
    Type: Grant
    Filed: July 21, 2009
    Date of Patent: December 11, 2012
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Hidemitsu Sakamoto, Yasuyuki Fujiwara
  • Publication number: 20120160153
    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: Application
    Filed: December 15, 2011
    Publication date: June 28, 2012
    Inventors: Tomokazu ISHII, Hidemitsu Sakamoto, Kazuhiko Kusunoki, Kazuhito Kamei
  • Publication number: 20120103251
    Abstract: PROBLEM To provide a seed crystal axis for solution growth of single crystal able to prevent or suppress formation of polycrystals due to the liquid phase technique and grow a single crystal with a high growth rate.
    Type: Application
    Filed: July 21, 2009
    Publication date: May 3, 2012
    Inventors: Hidemitsu Sakamoto, Yasuyuki Fujiwara
  • Patent number: 8118933
    Abstract: Silicon raw material is filled into a graphite crucible (10), the graphite crucible (10) is heated to form molten silicon (M), at least one rare earth element and at least one of Sn, Al, and Ge are added to molten silicon (M), and a temperature gradient is maintained in the molten silicon in which the temperature decreases from within the molten silicon toward the surface while growing an silicon carbide single crystal starting from an silicon carbide seed crystal (14) held immediately below the surface of the molten liquid.
    Type: Grant
    Filed: April 5, 2007
    Date of Patent: February 21, 2012
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Hidemitsu Sakamoto, Yukio Terashima
  • Publication number: 20110315073
    Abstract: In a method of producing an SiC single crystal, the SiC single crystal is grown on an 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: Application
    Filed: March 11, 2010
    Publication date: December 29, 2011
    Inventors: Hidemitsu Sakamoto, Hironori Daikoku, Yasuyuki Fujiwara
  • Patent number: 8052793
    Abstract: A method for producing a silicon carbide single crystal, which comprises bringing a silicon carbide single crystal substrate into contact with a melt prepared by melting a raw material containing Si and C, and growing a silicon carbide single crystal on the substrate, the method including performing a cycle comprising the following steps (a) and (b): a) a step of bringing the seed crystal substrate into contact with the surface of the melt, growing a single crystal, and separating the seed crystal substrate from the surface of the melt thereby interrupting the growth of the single crystal, and b) a step of bringing the seed crystal substrate into contact with the surface of the melt and growing a single crystal, at least one time, wherein the seed crystal is a 6H-silicon carbide single crystal or a 15R-silicon carbide single crystal and the resulting single crystal is a 4H-silicon carbide single crystal.
    Type: Grant
    Filed: June 16, 2006
    Date of Patent: November 8, 2011
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventor: Hidemitsu Sakamoto
  • Publication number: 20100083896
    Abstract: 5 to 30 at % of Ti and 1 to 20 at % of Sn or 1 to 30 at % of Ge are added to an Si melt, and SiC single crystal are grown from SiC seed crystal by holding the SiC seed crystal immediately beneath the surface of the Si melt in a graphite crucible while maintaining temperature gradient descending from the inner side of the Si melt to the surface of the melt.
    Type: Application
    Filed: June 10, 2008
    Publication date: April 8, 2010
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventor: Hidemitsu Sakamoto
  • Publication number: 20090178610
    Abstract: Silicon raw material is filled into a graphite crucible (10), the graphite crucible (10) is heated to form molten silicon (M), at least one rare earth element and at least one of Sn, Al, and Ge are added to molten silicon (M), and a temperature gradient is maintained in the molten silicon in which the temperature decreases from within the molten silicon toward the surface while growing an silicon carbide single crystal starting from an silicon carbide seed crystal (14) held immediately below the surface of the molten liquid.
    Type: Application
    Filed: April 5, 2007
    Publication date: July 16, 2009
    Inventors: Hidemitsu Sakamoto, Yukio Terashima
  • Publication number: 20090101062
    Abstract: A method for producing a silicon carbide single crystal, which comprises bringing a silicon carbide single crystal substrate into contact with a melt prepared by melting a raw material containing Si and C, and growing a silicon carbide single crystal on the substrate, the method including performing a cycle comprising the following steps (a) and (b): a) a step of bringing the seed crystal substrate into contact with the surface of the melt, growing a single crystal, and separating the seed crystal substrate from the surface of the melt thereby interrupting the growth of the single crystal, and b) a step of bringing the seed crystal substrate into contact with the surface of the melt and growing a single crystal, at least one time, wherein the seed crystal is a 6H-silicon carbide single crystal or a 15R-silicon carbide single crystal and the resulting single crystal is a 4H-silicon carbide single crystal.
    Type: Application
    Filed: June 16, 2006
    Publication date: April 23, 2009
    Applicant: Toyota Jidosha Kabushiki Kaisha
    Inventor: Hidemitsu Sakamoto
  • Publication number: 20090084309
    Abstract: A method of production of SiC single crystal using the solution method able to stably maintain flatness of a growth surface, prevent polycrystallization, and grow a large sized SiC single crystal is provided. A method of growing a hexagonal SiC single crystal starting from a hexagonal SiC seed crystal held directly under a melt surface of an Si melt in a graphite crucible by maintaining in the Si melt a temperature gradient such that the temperature falls from the inside toward the melt surface of the Si melt, characterized by: growing said SiC single crystal on a surface of said SiC seed crystal, which surface is inclined at a selected off angle from a (0001) plane of the SiC seed crystal in a [1-100] direction of the SiC seed crystal. The off angle is preferably 1 to 30°, while growing the SiC single crystal on the (1-100) surface where the off angle is 90° is most preferable.
    Type: Application
    Filed: January 18, 2007
    Publication date: April 2, 2009
    Inventor: Hidemitsu Sakamoto