Patents by Inventor Naohiro Sugiyama

Naohiro Sugiyama 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: 6451112
    Abstract: A crucible for growing a single crystal therein has a seed crystal attachment portion and a peripheral portion surrounding the seed crystal attachment portion through a gap provided therebetween. The seed crystal attachment portion has a support surface for holding a seed crystal on which the single crystal is to be grown, and the support surface is recessed from a surface of the peripheral portion. The seed crystal is attached to the support surface to cover an entire area of the support surface. Accordingly, no poly crystal is formed on the seed crystal attachment portion, and the single crystal can be grown on the seed crystal with high quality.
    Type: Grant
    Filed: October 12, 2000
    Date of Patent: September 17, 2002
    Assignee: Denso Corporation
    Inventors: Kazukuni Hara, Kouki Futatsuyama, Shoichi Onda, Fusao Hirose, Emi Oguri, Naohiro Sugiyama, Atsuto Okamoto
  • Publication number: 20020083892
    Abstract: It is the purpose of the present invention to prevent a macroscopic defect in the production of an SiC single crystal. SiC source material powder and an SiC seed crystal are disposed inside a graphite crucible, and the SiC source material powder is thermally sublimated and recrystallized on a front surface of the SiC seed crystal to grow an SiC single crystal. In this sublimation-recrystallization method, a protection layer is provided on a back surface of the SiC seed crystal. The SiC seed crystal is mechanically supported by a supporting part disposed on the graphite crucible without bonding. Thereby, it is possible to improve the thermal maldistribution on the back surface of the SiC seed crystal and possible to suppress damage of the protection layer due to the thermal maldistribution. Thus, macroscopic defects in the grown SiC single crystal are preferably suppressed.
    Type: Application
    Filed: December 21, 2001
    Publication date: July 4, 2002
    Inventors: Hiroyuki Kondo, Emi Oguri, Fusao Hirose, Daisuke Nakamura, Atsuto Okamoto, Naohiro Sugiyama
  • Patent number: 6214108
    Abstract: Micropipe defects existing in a silicon carbide single crystal are closed within the single crystal. At least a portion of the micropipe defects opened on the surface of the silicon carbide single crystal (SiC substrate) is sealed up with a coating material. Then heat treatment is performed so as to saturate the inside of the micropipe defects with silicon carbide vapors. By this, the micropipe defects existing in the SiC substrate can be closed within the SiC substrate, not in a newly grown layer. Further, the micropipe defects can be efficiently closed by filling the micropipe defects with a silicon carbide material by preliminarily using super critical fluid and the like.
    Type: Grant
    Filed: May 26, 1999
    Date of Patent: April 10, 2001
    Assignees: Kabushiki Kaisha Toyota Chuo Kenkyusho, Denso Corporation
    Inventors: Atsuto Okamoto, Naohiro Sugiyama, Toshihiko Tani, Nobuo Kamiya, Hiroaki Wakayama, Yoshiaki Fukushima, Kazukuni Hara, Fusao Hirose, Shoichi Onda, Kunihiko Hara, Takashi Onoda, Haruyoshi Kuriyama, Takeshi Hasegawa
  • Patent number: 5964944
    Abstract: An easy and low-cost method of producing a large-size and high-purity silicon carbide (SiC) single crystal includes reacting silicon vapor directly with a carbon-containing compound gas under a heated atmosphere (growth space 14) to grow a silicon carbide single crystal (15) on a silicon carbide seed crystal (12), in which the silicon vapor generated from molten silicon (13) is used as a silicon vapor source, and a hydrocarbon gas (9) (e.g., propane gas) is used as the carbon-containing compound gas.
    Type: Grant
    Filed: March 21, 1997
    Date of Patent: October 12, 1999
    Assignee: Kabushiki Kaisha Toyota Chuo Kenkyusho
    Inventors: Naohiro Sugiyama, Atsuto Okamoto, Toshihiko Tani, Nobuo Kamiya
  • Patent number: 5944890
    Abstract: In a method of producing single crystals on a seed crystal, the seed crystal is covered by a protection layer except for a surface on which the single crystals are to be formed. The protection layer is made of material such as carbon or the like, which is stable in a step of forming the single crystals. As a result, a temperature gradient and mass transfer in the seed crystal can be prevented, whereby quality of the single crystals formed on the seed crystal can be improved.
    Type: Grant
    Filed: March 28, 1997
    Date of Patent: August 31, 1999
    Assignee: Denso Corporation
    Inventors: Yasuo Kitou, Naohiro Sugiyama, Atsuto Okamoto, Toshihiko Tani, Nobuo Kamiya
  • Patent number: 5895526
    Abstract: A process for growing a single crystal comprises providing a single crystal substrate acting as a seed crystal above a source material in a container, heating the source material in an inert gas atmosphere in the container to form a sublimed source material, and discharging the sublimed source material from the container through a port above the single crystal substrate, to cause the sublimed source material to flow along and in parallel with a surface of the single crystal substrate, and grow a single crystal on the surface of the single crystal substrate.
    Type: Grant
    Filed: August 6, 1996
    Date of Patent: April 20, 1999
    Assignee: Nippondenso Co., Ltd.
    Inventors: Yasuo Kitoh, Masahiko Suzuki, Naohiro Sugiyama