Patents by Inventor Yutaka Shiga

Yutaka Shiga 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: 20240142390
    Abstract: A method for evaluating crystal defects in a silicon carbide single crystal wafer, the method including steps of: etching a silicon carbide single crystal wafer with melted KOH so that a size of an etch pit due to a threading edge dislocation is 10 to 50 ?m; obtaining microscopic images by automatic photographing at a plurality of positions on a surface of the silicon carbide single crystal wafer after the etching; determining presence or absence of a defect dense part in each of all the obtained microscopic images based on a continued length of the etch pit formed by the etching; and classifying all the obtained microscopic images into microscopic images having the defect dense part and microscopic images not having the defect dense part to evaluate a dense state of crystal defects in the silicon carbide single crystal wafer.
    Type: Application
    Filed: February 25, 2022
    Publication date: May 2, 2024
    Applicant: SHIN-ETSU HANDOTAI CO., LTD.
    Inventors: Yutaka SHIGA, Toru TAKAHASHI, Hisao MURAKI
  • Patent number: 8729676
    Abstract: The present invention includes a method for manufacturing a silicon epitaxial wafer having a silicon homoepitaxial layer formed on a surface of a silicon single crystal wafer, including the steps of: preparing the silicon single crystal wafer such that a plane orientation of the silicon single crystal wafer is tilted at an angle in the range from 0.1° to 8° in a <112> direction from a {110} plane; and growing the silicon homoepitaxial layer on the prepared silicon single crystal wafer. According to the present invention, a silicon epitaxial wafer using the {110} substrate with improved surface quality, such as Haze and surface roughness and a method for manufacturing the silicon epitaxial wafer are provided.
    Type: Grant
    Filed: April 28, 2011
    Date of Patent: May 20, 2014
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Yutaka Shiga, Hiroshi Takeno
  • Publication number: 20130037920
    Abstract: The present invention includes a method for manufacturing a silicon epitaxial wafer having a silicon homoepitaxial layer formed on a surface of a silicon single crystal wafer, including the steps of: preparing the silicon single crystal wafer such that a plane orientation of the silicon single crystal wafer is tilted at an angle in the range from 0.1° to 8° in a <112> direction from a {110} plane; and growing the silicon homoepitaxial layer on the prepared silicon single crystal wafer. According to the present invention, a silicon epitaxial wafer using the {110} substrate with improved surface quality, such as Haze and surface roughness and a method for manufacturing the silicon epitaxial wafer are provided.
    Type: Application
    Filed: April 28, 2011
    Publication date: February 14, 2013
    Applicant: SHIN-ETSU HANDOTAI CO., LTD.
    Inventors: Yutaka Shiga, Hiroshi Takeno