Patents by Inventor Yohei KAGOYAMA

Yohei KAGOYAMA 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: 20220367642
    Abstract: A type, size, and location of a crystal defect of an epitaxial layer of a semiconductor wafer containing silicon carbide are detected from a PL image by crystal defect inspection equipment. Detected crystal defects include a triangular polymorph stacking fault generated in the epitaxial layer during epitaxial growth and high-density BPDs extending from the stacking fault and present bundled between the stacking fault and a perfect crystal. Next, a chip region free of the triangular polymorph stacking fault and free of the high-density BPD in a specified area that is in the termination region and is located closer to a chip center than is a specified position is identified as a conforming product. A semiconductor chip set as a conforming product may contain high-density BPDs outside the specified area.
    Type: Application
    Filed: March 29, 2022
    Publication date: November 17, 2022
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventor: Yohei KAGOYAMA
  • Publication number: 20220254917
    Abstract: A silicon carbide semiconductor device being capable of operating at least 100 degree C., includes a semiconductor substrate having an active region, the semiconductor substrate having first and second surfaces opposite to each other, a first semiconductor region of an n type, provided in the semiconductor substrate, a second semiconductor region of a p type, provided in the active region, between the first surface of the semiconductor substrate and the first semiconductor region, and a device element structure including a pn junction between the second and first semiconductor regions that forms a body diode through which a current flows when the semiconductor device is turned on. A stacking fault area that is a sum of areas that contain stacking faults within an entire active region of the first surface of the semiconductor substrate in the first surface is set to be greater, the higher a breakdown voltage is set.
    Type: Application
    Filed: January 4, 2022
    Publication date: August 11, 2022
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventors: Yohei KAGOYAMA, Masaki MIYAZATO