Patents by Inventor Hirofumi Ooki

Hirofumi Ooki 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: 7846799
    Abstract: A manufacturing method is provided for a power semiconductor device that enables reducing its on-state voltage and power loss. The semiconductor device includes a set of L-shaped trench gates 3 each formed, from the top-side surface of a p base layer 2, perpendicularly with respect to a first main surface of an n? layer 1, to reach into a location of the n? layer 1. At the lower ends of each of the trench gates 3, bottom portions 3d are provided to unilaterally extend a predetermined length in one direction parallel to the first main surface of the n? layer 1. In addition, the extending end of one of the bottom portions 3d opposes that of the other bottom portion, on the extending side of the bottom portions 3d, and the interspace between each pair of adjacent bottom portions 3d is set narrower than any other interspace between the trench-gate parts that are perpendicularly formed with respect to the first main surface of the n? layer 1.
    Type: Grant
    Filed: June 29, 2010
    Date of Patent: December 7, 2010
    Assignee: Mitsubishi Electric Corporation
    Inventor: Hirofumi Ooki
  • Publication number: 20100267209
    Abstract: A manufacturing method is provided for a power semiconductor device that enables reducing its on-state voltage and power loss. The semiconductor device includes a set of L-shaped trench gates 3 each formed, from the top-side surface of a p base layer 2, perpendicularly with respect to a first main surface of an n? layer 1, to reach into a location of the n? layer 1. At the lower ends of each of the trench gates 3, bottom portions 3d are provided to unilaterally extend a predetermined length in one direction parallel to the first main surface of the n? layer 1. In addition, the extending end of one of the bottom portions 3d opposes that of the other bottom portion, on the extending side of the bottom portions 3d, and the interspace between each pair of adjacent bottom portions 3d is set narrower than any other interspace between the trench-gate parts that are perpendicularly formed with respect to the first main surface of the n? layer 1.
    Type: Application
    Filed: June 29, 2010
    Publication date: October 21, 2010
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventor: Hirofumi OOKI
  • Patent number: 7791134
    Abstract: A semiconductor device which includes a set of trench gates each formed, from the top-side surface of a p base layer, perpendicularly with respect to a first main surface of an p-layer, to reach into a location of the n-layer. At the lower ends of each of the trench gates, bottom portions are provided to unilaterally extend a predetermined length in one direction parallel to the first main surface of the n-layer. In addition, the extending end of one of the bottom portions opposes that of the other bottom portion, on the extending side of the bottom portions, and the distance between each pair of adjacent bottom portions is set narrower than any other distance between the trench-gate parts that are perpendicularly formed with respect to the first main surface of the n-layer.
    Type: Grant
    Filed: June 28, 2007
    Date of Patent: September 7, 2010
    Assignee: Mitsubishi Electric Corporation
    Inventor: Hirofumi Ooki
  • Publication number: 20080054351
    Abstract: A power semiconductor device and its manufacturing method are provided that enable reducing its on-state voltage and power loss. The semiconductor device includes a set of L-shaped trench gates 3 each formed, from the top-side surface of a p base layer 2, perpendicularly with respect to a first main surface of an n? layer 1, to reach into a location of the n? layer 1. At the lower ends of each of the trench gates 3, bottom portions 3d are provided to unilaterally extend a predetermined length in one direction parallel to the first main surface of the n? layer 1. In addition, the extending end of one of the bottom portions 3d opposes that of the other bottom portion, on the extending side of the bottom portions 3d, and the interspace between each pair of adjacent bottom portions 3d is set narrower than any other interspace between the trench-gate parts that are perpendicularly formed with respect to the first main surface of the n? layer 1.
    Type: Application
    Filed: June 28, 2007
    Publication date: March 6, 2008
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventor: Hirofumi OOKI