Patents by Inventor Katsuhiro Fujiyoshi

Katsuhiro Fujiyoshi 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: 20240355922
    Abstract: A semiconductor device includes: a drift layer of a first conductivity type; well layers of a second conductivity type; a source layer of a first conductivity type; a gate electrode; an interlayer insulating film; and a source electrode, in which a plurality of body diodes constituted by the well layer and the drift layer at positions not overlapping with the gate electrode in plan view include a first operation portion that operates at a first body diode operation voltage and a plurality of second operation portions that operate at a second body diode operation voltage lower than the first body diode operation voltage.
    Type: Application
    Filed: January 16, 2024
    Publication date: October 24, 2024
    Applicant: Mitsubishi Electric Corporation
    Inventors: Katsutoshi SUGAWARA, Kotaro KAWAHARA, Akifumi IIJIMA, Shiro HINO, Katsuhiro FUJIYOSHI
  • Publication number: 20230053501
    Abstract: A silicon carbide semiconductor device includes an n-type epitaxial layer provided on a SiC substrate, a front surface electrode provided on the epitaxial layer, and a p-type electric field relieving region provided in the upper layer of the epitaxial layer in a terminal region. On the epitaxial layer, a first protective film composed of an interlayer insulating film and a protective oxide film that covers at least a part of the electric field relieving region is provided. A second protective film composed of a polyimide protective film is provided via a silicon nitride film so as to cover the outer end portion of the surface electrode, the first protective film, and at least a part of the epitaxial layer. The silicon nitride film protrudes from the second protective film at both an inner side end portion and an outer side end portion.
    Type: Application
    Filed: June 28, 2022
    Publication date: February 23, 2023
    Applicant: Mitsubishi Electric Corporation
    Inventors: Katsuhiro FUJIYOSHI, Toshikazu TANIOKA
  • Patent number: 7065238
    Abstract: Transforming optical images of a portion including a normal conductor pattern having a surface roughness, a portion subjected to an inspection, and a reference portion to images of electric charges and picking up these as electric signals by an image pick-up device, rendering the optical image including the normal conductor pattern having the surface roughness to a pixel signal by the image pick-up device, controlling a light volume of the optical image so that the pixel signal is saturated or immediately before the saturation, picking up a pixel signal of the portion to be inspected under this light volume, obtaining a differential signal from a pixel signal picked up from the reference portion, and judging an existence of defect from the differential signal, so as to detect defects such as a hiatus of conductor, a short circuit, and a deposition of an extraneous matter on a wafer, on which the normal conductor pattern having the roughened surface, with a high accuracy in processes of forming films and etchi
    Type: Grant
    Filed: September 7, 2001
    Date of Patent: June 20, 2006
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Ayumu Onoyama, Koichi Sakurai, Kazuhiro Oka, Hiroyuki Ishii, Katsuhiro Fujiyoshi
  • Publication number: 20030048940
    Abstract: Transforming optical images of a portion including a normal conductor pattern having a surface roughness, a portion subjected to an inspection, and a reference portion to images of electric charges and picking up these as electric signals by an image pick-up device, rendering the optical image including the normal conductor pattern having the surface roughness to a pixel signal by the image pick-up device, controlling a light volume of the optical image so that the pixel signal is saturated or immediately before the saturation, picking up a pixel signal of the portion to be inspected under this light volume, obtaining a differential signal from a pixel signal picked up from the reference portion, and judging an existence of defect from the differential signal, so as to detect defects such as a hiatus of conductor, a short circuit, and a deposition of an extraneous matter on a wafer, on which the normal conductor pattern having the roughened surface, with a high accuracy in processes of forming films and etchi
    Type: Application
    Filed: September 7, 2001
    Publication date: March 13, 2003
    Inventors: Ayumu Onoyama, Koichi Sakurai, Kazuhiro Oka, Hiroyuki Ishii, Katsuhiro Fujiyoshi