Patents by Inventor Yoshiyuki Hisada

Yoshiyuki Hisada 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: 7968892
    Abstract: A silicon carbide semiconductor device includes: a semiconductor substrate having a principal surface and a backside surface; a drift layer disposed on the principal surface; a base region disposed on the drift layer; a source region disposed on the base region; a surface channel layer disposed on both of the drift layer and the base region for connecting between the source region and the drift layer; a gate insulation film disposed on the surface channel layer and including a high dielectric constant film; a gate electrode disposed on the gate insulation film; a source electrode disposed on the source region; and a backside electrode disposed on the backside surface.
    Type: Grant
    Filed: July 31, 2007
    Date of Patent: June 28, 2011
    Assignee: Denso Corporation
    Inventors: Jun Kojima, Takeshi Endo, Eiichi Okuno, Yoshihito Mitsuoka, Yoshiyuki Hisada, Hideo Matsuki
  • Patent number: 7365363
    Abstract: A silicon carbide semiconductor device includes: a semiconductor substrate having a principal surface and a backside surface; a drift layer disposed on the principal surface; a base region disposed on the drift layer; a source region disposed on the base region; a surface channel layer disposed on both of the drift layer and the base region for connecting between the source region and the drift layer; a gate insulation film disposed on the surface channel layer and including a high dielectric constant film; a gate electrode disposed on the gate insulation film; a source electrode disposed on the source region; and a backside electrode disposed on the backside surface.
    Type: Grant
    Filed: April 19, 2005
    Date of Patent: April 29, 2008
    Assignee: DENSO CORPORATION
    Inventors: Jun Kojima, Takeshi Endo, Eiichi Okuno, Yoshihito Mitsuoka, Yoshiyuki Hisada, Hideo Matsuki
  • Publication number: 20070281173
    Abstract: A silicon carbide semiconductor device includes: a semiconductor substrate having a principal surface and a backside surface; a drift layer disposed on the principal surface; a base region disposed on the drift layer; a source region disposed on the base region; a surface channel layer disposed on both of the drift layer and the base region for connecting between the source region and the drift layer; a gate insulation film disposed on the surface channel layer and including a high dielectric constant film; a gate electrode disposed on the gate insulation film; a source electrode disposed on the source region; and a backside electrode disposed on the backside surface.
    Type: Application
    Filed: July 31, 2007
    Publication date: December 6, 2007
    Applicant: DENSO CORPORATION
    Inventors: Jun Kojima, Takeshi Endo, Eiichi Okuno, Yoshihito Mitsuoka, Yoshiyuki Hisada, Hideo Matsuki
  • Patent number: 7045879
    Abstract: The principal surface of a p-type SiC substrate (1) is formed of a face intersecting (0001) Si-face at 10 to 16°. An n+ source region (2) and an n+ drain region (3) are formed in a surface layer portion at the principal surface of the p-type SiC substrate (1) so as to be separated from each other. A gate electrode (5) is formed on a gate oxide film (4) on the principal surface of the p-type SiC substrate (1).
    Type: Grant
    Filed: December 24, 2003
    Date of Patent: May 16, 2006
    Assignee: Denso Corporation
    Inventors: Yoshiyuki Hisada, Eiichi Okuno, Yoshihito Mitsuoka, Shinji Amano, Takeshi Endo, Shinichi Mukainakano, Ayahiko Ichimiya
  • Publication number: 20050230686
    Abstract: A silicon carbide semiconductor device includes: a semiconductor substrate having a principal surface and a backside surface; a drift layer disposed on the principal surface; a base region disposed on the drift layer; a source region disposed on the base region; a surface channel layer disposed on both of the drift layer and the base region for connecting between the source region and the drift layer; a gate insulation film disposed on the surface channel layer and including a high dielectric constant film; a gate electrode disposed on the gate insulation film; a source electrode disposed on the source region; and a backside electrode disposed on the backside surface.
    Type: Application
    Filed: April 19, 2005
    Publication date: October 20, 2005
    Inventors: Jun Kojima, Takeshi Endo, Eiichi Okuno, Yoshihito Mitsuoka, Yoshiyuki Hisada, Hideo Matsuki
  • Publication number: 20050064639
    Abstract: In a method of fabricating a SiC semiconductor device, a surface of a SiC layer (5, 48, 102) is processed into a cleaned surface terminated at Si. An oxide film (7, 49, 105) is formed on the cleaned surface of the SiC layer. The SiC layer with the oxide film is subjected to thermal oxidation at a temperature in a range of 700° C. to 900° C. so that only terminal Si at the cleaned surface of the SiC layer is oxidated and an interface between the oxide film and the SiC layer becomes an SiO2/SiC cleaned interface.
    Type: Application
    Filed: October 12, 2004
    Publication date: March 24, 2005
    Inventors: Yoshiyuki Hisada, Eiichi Okuno, Takeshi Hasegawa
  • Patent number: 6841436
    Abstract: In a method of fabricating a SiC semiconductor device, a surface of a SiC layer (5, 48, 102) is processed into a cleaned surface terminated at Si. An oxide film (7, 49, 105) is formed on the cleaned surface of the SiC layer. The SiC layer with the oxide film is subjected to thermal oxidation at a temperature in a range of 700° C. to 900° C. so that only terminal Si at the cleaned surface of the SiC layer is oxidated and an interface between the oxide film and the SiC layer becomes an SiO2/SiC cleaned interface.
    Type: Grant
    Filed: October 10, 2002
    Date of Patent: January 11, 2005
    Assignee: Denso Corporation
    Inventors: Yoshiyuki Hisada, Eiichi Okuno, Takeshi Hasegawa
  • Publication number: 20040159841
    Abstract: The principal surface of a p-type SiC substrate (1) is formed of a face intersecting (0001) Si-face at 10 to 16°. An n+ source region (2) and an n+ drain region (3) are formed in a surface layer portion at the principal surface of the p-type SiC substrate (1) so as to be separated from each other. A gate electrode (5) is formed on a gate oxide film (4) on the principal surface of the p-type SiC substrate (1).
    Type: Application
    Filed: December 24, 2003
    Publication date: August 19, 2004
    Inventors: Yoshiyuki Hisada, Eiichi Okuno, Yoshihito Mitsuoka, Shinji Amano, Takeshi Endo, Shinichi Mukainakano, Ayahiko Ichimiya
  • Patent number: 6589337
    Abstract: In a process of producing a SiC device, a Si layer is formed on the surface of a SiC substrate, and the Si layer is removed from the surface of the SiC substrate by supplying oxygen gas to the Si layer in a high ambient temperature and a low ambient pressure. The pressure is set at 1×10−2 to 1×10−6 Pa. Thus a cleaned surface of the SiC substrate, not contaminated by carbon and the like in atmospheric air, can be provided. Preferably, the oxygen pressure and temperature are set at about 10−6 Pa and 1000° C. for removing the Si layer. Thereafter, the oxygen is further supplied to raise the pressure to about 104 Pa to form an oxide film on the cleaned SiC substrate. Thus, the SiC substrate is cleaned and then formed with the oxide layer in the same chamber by changing the ambient pressure but without changing the ambient temperature.
    Type: Grant
    Filed: September 5, 2001
    Date of Patent: July 8, 2003
    Assignee: Denso Corporation
    Inventors: Yoshiyuki Hisada, Shinichi Mukainakano, Takeshi Hasegawa, Ayahiko Ichimiya, Tomohiro Aoyama, Kiyoshige Kato
  • Publication number: 20030073270
    Abstract: In a method of fabricating a SiC semiconductor device, a surface of a SiC layer (5, 48, 102) is processed into a cleaned surface terminated at Si. An oxide film (7, 49, 105) is formed on the cleaned surface of the SiC layer. The SiC layer with the oxide film is subjected to thermal oxidation at a temperature in a range of 700° C. to 900° C. so that only terminal Si at the cleaned surface of the SiC layer is oxidated and an interface between the oxide film and the SiC layer becomes an SiO2/SiC cleaned interface.
    Type: Application
    Filed: October 10, 2002
    Publication date: April 17, 2003
    Inventors: Yoshiyuki Hisada, Eiichi Okuno, Takeshi Hasegawa
  • Publication number: 20020033130
    Abstract: In a process of producing a SiC device, a Si layer is formed on the surface of a SiC substrate, and the Si layer is removed from the surface of the SiC substrate by supplying oxygen gas to the Si layer in a high ambient temperature and a low ambient pressure. The pressure is set at 1×10−2 to 1×10−6 Pa. Thus a cleaned surface of the SiC substrate, not contaminated by carbon and the like in atmospheric air, can be provided. Preferably, the oxygen pressure and temperature are set at about 10−6 Pa and 1000° C. for removing the Si layer. Thereafter, the oxygen is further supplied to raise the pressure to about 104 Pa to form an oxide film on the cleaned SiC substrate. Thus, the SiC substrate is cleaned and then formed with the oxide layer in the same chamber by changing the ambient pressure but without changing the ambient temperature.
    Type: Application
    Filed: September 5, 2001
    Publication date: March 21, 2002
    Inventors: Yoshiyuki Hisada, Shinichi Mukainakano, Takeshi Hasegawa, Ayahiko Ichimiya, Tomohiro Aoyama, Kiyoshige Kato