Patents by Inventor Masato Tsumori

Masato Tsumori 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: 20140159057
    Abstract: There is provided a silicon carbide semiconductor device having excellent electrical characteristics such as channel mobility, and a method for manufacturing the same. A semiconductor device includes a substrate made of silicon carbide and having an off-angle of greater than or equal to 50° and less than or equal to 65° with respect to a surface orientation of {0001}, a p-type layer serving as a semiconductor layer, and an oxide film serving as an insulating film. The p-type layer is formed on the substrate and is made of silicon carbide. The oxide film is formed to contact with a surface of the p-type layer. A maximum value of the concentration of nitrogen atoms in a region within 10 nm of an interface between the semiconductor layer and the insulating film (interface between a channel region and the oxide film) is greater than or equal to 1×1021 cm?3.
    Type: Application
    Filed: February 12, 2014
    Publication date: June 12, 2014
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Shin Harada, Takeyoshi Masuda, Keiji Wada, Masato Tsumori
  • Publication number: 20140159056
    Abstract: There is provided a silicon carbide semiconductor device having excellent electrical characteristics such as channel mobility, and a method for manufacturing the same. A semiconductor device includes a substrate made of silicon carbide and having an off-angle of greater than or equal to 50° and less than or equal to 65° with respect to a surface orientation of {0001}, a p-type layer serving as a semiconductor layer, and an oxide film serving as an insulating film. The p-type layer is formed on the substrate and is made of silicon carbide. The oxide film is formed to contact with a surface of the p-type layer. A maximum value of the concentration of nitrogen atoms in a region within 10 nm of an interface between the semiconductor layer and the insulating film (interface between a channel region and the oxide film) is greater than or equal to 1×1021 cm?3.
    Type: Application
    Filed: February 12, 2014
    Publication date: June 12, 2014
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Shin Harada, Takeyoshi Masuda, Keiji Wada, Masato Tsumori
  • Patent number: 8686434
    Abstract: There is provided a silicon carbide semiconductor device having excellent electrical characteristics such as channel mobility, and a method for manufacturing the same. A semiconductor device includes a substrate made of silicon carbide and having an off-angle of greater than or equal to 50° and less than or equal to 65° with respect to a surface orientation of {0001}, a p-type layer serving as a semiconductor layer, and an oxide film serving as an insulating film. The p-type layer is formed on the substrate and is made of silicon carbide. The oxide film is formed to contact with a surface of the p-type layer. A maximum value of the concentration of nitrogen atoms in a region within 10 nm of an interface between the semiconductor layer and the insulating film (interface between a channel region and the oxide film) is greater than or equal to 1×1021 cm?3.
    Type: Grant
    Filed: February 3, 2009
    Date of Patent: April 1, 2014
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Shin Harada, Takeyoshi Masuda, Keiji Wada, Masato Tsumori
  • Patent number: 8421086
    Abstract: A silicon carbide semiconductor device having an active layer with reduced defect density which is formed on a substrate made of silicon carbide, and a method of manufacturing the same are provided. A semiconductor device includes a substrate made of silicon carbide and having an off angle of not less than 50° and not more than 65° with respect to a plane orientation {0001}; a buffer layer, and an epitaxial layer, a p-type layer and an n+ region each serving as an active layer. The buffer layer is made of silicon carbide and formed on the substrate. The active layer is made of silicon carbide and formed on the buffer layer. The micropipe density is lower in the active layer than in the substrate. The density of dislocations in which the direction of a Burgers vector corresponds to is higher in the active layer than in the substrate.
    Type: Grant
    Filed: February 3, 2009
    Date of Patent: April 16, 2013
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Shin Harada, Masato Tsumori
  • Publication number: 20110186862
    Abstract: There is provided a silicon carbide semiconductor device having excellent electrical characteristics such as channel mobility, and a method for manufacturing the same. A semiconductor device includes a substrate made of silicon carbide and having an off-angle of greater than or equal to 50° and less than or equal to 65° with respect to a surface orientation of {0001}, a p-type layer serving as a semiconductor layer, and an oxide film serving as an insulating film. The p-type layer is formed on the substrate and is made of silicon carbide. The oxide film is formed to contact with a surface of the p-type layer. A maximum value of the concentration of nitrogen atoms in a region within 10 nm of an interface between the semiconductor layer and the insulating film (interface between a channel region and the oxide film) is greater than or equal to 1×1021 cm?3.
    Type: Application
    Filed: February 3, 2009
    Publication date: August 4, 2011
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Shin Harada, Takeyoshi Masuda, Keiji Wada, Masato Tsumori
  • Publication number: 20110031505
    Abstract: A silicon carbide semiconductor device having an active layer with reduced defect density which is formed on a substrate made of silicon carbide, and a method of manufacturing the same are provided. A semiconductor device includes a substrate made of silicon carbide and having an off angle of not less than 50° and not more than 65° with respect to a plane orientation; a buffer layer, and an epitaxial layer, a p-type layer and an n+ region each serving as an active layer. The buffer layer is made of silicon carbide and formed on the substrate. The active layer is made of silicon carbide and formed on the buffer layer. The micropipe density is lower in the active layer than in the substrate. The density of dislocations in which the direction of a Burgers vector corresponds to is higher in the active layer than in the substrate.
    Type: Application
    Filed: February 3, 2009
    Publication date: February 10, 2011
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Shin Harada, Masato Tsumori