Patents by Inventor Kazuhito Kamei

Kazuhito Kamei 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: 9631295
    Abstract: Provided is a method for producing SiC single crystals while maintaining a temperature gradient such that the temperature decreases from within an Si solution inside a graphite crucible toward the solution surface, with the SiC seed crystals that have contacted the solution surface serving as the starting point for crystal seed growth, wherein when the crystal growth surface of the SiC seed crystals, which serves as the starting point for SiC single crystal growth, contacts the solution surface, the height by which the solution rises to the side of the SiC seed crystals is within the range where the SiC single crystals that have grown from the crystal growth surface and the SiC single crystals that have grown from the side grow as one SiC single crystal unit.
    Type: Grant
    Filed: July 27, 2011
    Date of Patent: April 25, 2017
    Assignees: TOYOTA JIDOSHA KABUSHIKI KAISHA, NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Hironori Daikoku, Kazuhito Kamei
  • 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: 20170067183
    Abstract: A method of manufacturing an SiC single crystal includes the steps of melting a raw material in a crucible (14) to produce an SIC solution (15); and bringing a crystal growth surface (24A) of an SiC seed crystal (24) into contact with the SiC solution to cause an SiC single crystal to grow on the crystal growth surface. The crystal structure of the SiC seed crystal is the 4H polytype. The off-angle of the crystal growth surface is not smaller than 1° and not larger than 4°. The temperature of the SIC solution during growth of the SiC single crystal is not lower than 1650° C. and not higher than 1850° C. The temperature gradient in a portion of the SiC solution directly below the SiC seed crystal during growth of the SiC single crystal is higher than 0° C./cm and not higher than 19° C./cm.
    Type: Application
    Filed: March 12, 2015
    Publication date: March 9, 2017
    Inventors: Kazuaki SEKI, Kazuhiko KUSUNOKI, Kazuhito KAMEI
  • 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: 9530642
    Abstract: Provided is a method for producing an SiC single crystal, which is capable of greatly increasing the growth rate in a solution technique in comparison to conventional methods. A method for producing an SiC single crystal, wherein an SiC single crystal is grown by bringing a seed crystal substrate into contact with an Si—C solution that is put in a crucible and has a temperature gradient decreasing from the inside to the liquid level, and wherein the value of depth/inner diameter of the crucible is less than 1.71 and the temperature gradient of the Si—C solution from the liquid level to 10 mm below the liquid level is larger than 42° C./cm.
    Type: Grant
    Filed: August 12, 2013
    Date of Patent: December 27, 2016
    Assignees: TOYOTA JIDOSHA KABUSHIKI KAISHA, NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Motohisa Kado, Kazuhiko Kusunoki, Kazuhito Kamei
  • Patent number: 9512540
    Abstract: A method for manufacturing an n-type SiC single crystal, enables the suppression of the variation in nitrogen concentration among a plurality of n-type SiC single crystal ingots manufactured. A method includes the steps of: providing a manufacturing apparatus (100) including a chamber (1) having an area in which a crucible (7) is to be disposed; heating the area in which the crucible (7) is to be disposed and evacuating the gas in the chamber (1); filling, after the evacuation, the chamber (1) with a mixed gas containing a noble gas and nitrogen gas; heating and melting a starting material housed in the crucible (7) disposed in the area to produce a SiC solution (8) containing silicon and carbon; and immersing a SiC seed crystal into the SiC solution under the mixed gas atmosphere to grow an n-type SiC single crystal on the SiC seed crystal.
    Type: Grant
    Filed: November 4, 2011
    Date of Patent: December 6, 2016
    Assignees: NIPPON STEEL & SUMITOMO METAL CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Kazuhiko Kusunoki, Kazuhito Kamei, Nobuyoshi Yashiro, Kouji Moriguchi, Nobuhiro Okada, Katsunori Danno, Hironori Daikoku
  • Publication number: 20160340794
    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: Application
    Filed: May 3, 2016
    Publication date: November 24, 2016
    Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Hironori DAIKOKU, Kazuhito KAMEI, Kazuhiko KUSUNOKI, Kazuaki SEKI, Yutaka KISHIDA
  • Publication number: 20160273126
    Abstract: Provided is a method for producing a SiC single crystal by a solution growth method, the production method being capable of growing a SiC single crystal doped with Al even when a graphite crucible is used. The production method according to an embodiment of the present invention includes the steps of: forming a Si—C solution in a graphite crucible, and bringing a SiC seed crystal into contact with the Si—C solution and growing the SiC single crystal on the SiC seed crystal. The Si—C solution contains Si, Al, and Cu in a range satisfying Formula (1), with the balance of the Si—C solution being C and impurities. In Formula (1), [Si], [Al], and [Cu] represent contents of Si, Al and Cu expressed by mol %, respectively. 0.03<[Cu]/([Si]+[Al]+[Cu])?0.
    Type: Application
    Filed: November 12, 2014
    Publication date: September 22, 2016
    Inventors: Kazuhiko Kusunoki, Kazuhito Kamei
  • Publication number: 20160237590
    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: Application
    Filed: August 27, 2014
    Publication date: August 18, 2016
    Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Hironori DAIKOKU, Motohisa KADO, Kazuhito KAMEI, Kazuhiko KUSUNOKI
  • 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
  • Patent number: 9222198
    Abstract: A SiC single crystal wafer on which a good quality epitaxial film by suppressing defects derived from the wafer can be grown has an affected surface layer with a thickness of at most 50 nm and a SiC single crystal portion with an oxygen content of at most 1.0×1017 atoms/cm3. This SiC single crystal wafer is manufactured from a high purity SiC bulk single crystal obtained by the solution growth method using raw materials with an oxygen content of at most 100 ppm and a non-oxidizing atmosphere having an oxygen concentration of at most 100 ppm.
    Type: Grant
    Filed: February 27, 2012
    Date of Patent: December 29, 2015
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Kazuhiko Kusunoki, Kazuhito Kamei, Nobuyoshi Yashiro, Junichi Koike
  • 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
  • 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: 20150221511
    Abstract: Provided is a method for producing an SiC single crystal, which is capable of greatly increasing the growth rate in a solution technique in comparison to conventional methods. A method for producing an SiC single crystal, wherein an SiC single crystal is grown by bringing a seed crystal substrate into contact with an Si—C solution that is put in a crucible and has a temperature gradient decreasing from the inside to the liquid level, and wherein the value of depth/inner diameter of the crucible is less than 1.71 and the temperature gradient of the Si—C solution from the liquid level to 10 mm below the liquid level is larger than 42° C./cm.
    Type: Application
    Filed: August 12, 2013
    Publication date: August 6, 2015
    Inventors: Motohisa Kado, Kazuhiko Kusunoki, Kazuhito Kamei
  • 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: 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: 20150136016
    Abstract: Provided is a method for producing a SiC single crystal wherein generation of polycrystals can be inhibited even if the temperature of the Si—C solution is changed after seed touching.
    Type: Application
    Filed: November 14, 2014
    Publication date: May 21, 2015
    Inventors: Katsunori DANNO, Kazuhiko KUSUNOKI, Kazuhito KAMEI