Patents by Inventor Atsuya Akiba

Atsuya Akiba 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: 7989231
    Abstract: In a method of manufacturing a silicon carbide semiconductor device, a trench and a thickness measurement section are formed in a surface of a semiconductor substrate made of silicon carbide. The thickness measurement section includes a plurality of grooves and a protruding portion provided between the grooves so as to have a predetermined width. When an epitaxial layer made of silicon carbide is grown, a thickness of the epitaxial layer formed on the surface of the semiconductor substrate is measured by calculating a difference in height between a surface of the epitaxial layer formed on a portion of the surface of the semiconductor substrate different from the thickness measurement section and a top surface of the protruding portion. The predetermined width is less than a surface migration amount of atoms during growth of the epitaxial layer.
    Type: Grant
    Filed: March 11, 2010
    Date of Patent: August 2, 2011
    Assignee: DENSO CORPORATION
    Inventors: Atsuya Akiba, Yuuichi Takeuchi
  • Patent number: 7947555
    Abstract: In a method of making a silicon carbide semiconductor device having a MOSFET, after a mask is placed on a surface of a first conductivity type drift layer of silicon carbide, ion implantation is performed by using the mask to form a lower layer of a deep layer extending in one direction. A first conductivity type current scattering layer having a higher concentration than the drift layer is formed on the surface of the drift layer. After another mask is placed on a surface of the current scattering layer, ion implantation is performed by using the other mask to form an upper layer of the deep layer at a position corresponding to the lower layer in such a manner that the lower layer and the upper layer are connected together.
    Type: Grant
    Filed: April 9, 2009
    Date of Patent: May 24, 2011
    Assignee: Denso Corporation
    Inventors: Atsuya Akiba, Eiichi Okuno
  • Publication number: 20100233832
    Abstract: In a method of manufacturing a silicon carbide semiconductor device, a trench and a thickness measurement section are formed in a surface of a semiconductor substrate made of silicon carbide. The thickness measurement section includes a plurality of grooves and a protruding portion provided between the grooves so as to have a predetermined width. When an epitaxial layer made of silicon carbide is grown, a thickness of the epitaxial layer formed on the surface of the semiconductor substrate is measured by calculating a difference in height between a surface of the epitaxial layer formed on a portion of the surface of the semiconductor substrate different from the thickness measurement section and a top surface of the protruding portion. The predetermined width is less than a surface migration amount of atoms during growth of the epitaxial layer.
    Type: Application
    Filed: March 11, 2010
    Publication date: September 16, 2010
    Applicant: DENSO CORPORATION
    Inventors: Atsuya Akiba, Yuuichi Takeuchi
  • Publication number: 20090280609
    Abstract: In a method of making a silicon carbide semiconductor device having a MOSFET, after a mask is placed on a surface of a first conductivity type drift layer of silicon carbide, ion implantation is performed by using the mask to form a lower layer of a deep layer extending in one direction. A first conductivity type current scattering layer having a higher concentration than the drift layer is formed on the surface of the drift layer. After another mask is placed on a surface of the current scattering layer, ion implantation is performed by using the other mask to form an upper layer of the deep layer at a position corresponding to the lower layer in such a manner that the lower layer and the upper layer are connected together.
    Type: Application
    Filed: April 9, 2009
    Publication date: November 12, 2009
    Applicant: DENSO CORPORATION
    Inventors: Atsuya Akiba, Eiichi Okuno