Patents by Inventor Yasushi Miyasaka

Yasushi Miyasaka 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: 20010046739
    Abstract: This invention clarifies the effects of parameters and enables the mass production of a super-junction semiconductor device, which has a drift layer composed of a parallel pn layer that conducts electricity in the ON state and is depleted in the OFF state. The quantity of impurities in n drift regions is within the range between 100% and 150% or between 110% and 150% of the quantity of impurities in p partition regions. The impurity density of either one of the n drift regions and the p partition regions is within the range between 92% and 108% of the impurity density of the other regions. In addition, the width of either one of the n drift regions and the p partition regions is within the range between 94% and 106% of the width of the other regions.
    Type: Application
    Filed: July 16, 2001
    Publication date: November 29, 2001
    Applicant: Fuji Electric, Co., Ltd.
    Inventors: Yasushi Miyasaka, Tatsuhiko Fujihira, Yasuhiko Ohnishi, Katsunori Ueno, Susumu Iwamoto
  • Publication number: 20010035560
    Abstract: A diode is provided which includes a first-conductivity-type cathode layer, a first-conductivity-type drift layer placed on the cathode region and having a lower concentration than the cathode layer, a generally ring-like second-conductivity-type ring region formed in the drift layer, second-conductivity-type anode region formed in the drift layer located inside the ring region, a cathode electrode formed in contact with the cathode layer, and an anode electrode formed in contact with the anode region, wherein the lowest resistivity of the second-conductivity-type anode region is at least {fraction (1/100)} of the resistivity of the drift layer, and the thickness of the anode region is smaller than the diffusion depth of the ring region.
    Type: Application
    Filed: February 26, 2001
    Publication date: November 1, 2001
    Applicant: Fuji Electric Co., Ltd.
    Inventors: Tatsuhiko Fujihira, Yasushi Miyasaka
  • Patent number: 6291856
    Abstract: This invention clarifies the effects of parameters and enables the mass production of a super-junction semiconductor device, which has a drift layer composed of a parallel pn layer that conducts electricity in the ON state and is depleted in the OFF state. The quantity of impurities in n drift regions is within the range between 100% and 150% or between 110% and 150% of the quantity of impurities in p partition regions. The impurity density of either one of the n drift regions and the p partition regions is within the range between 92% and 108% of the impurity density of the other regions. In addition, the width of either one of the n drift regions and the p partition regions is within the range between 94% and 106% of the width of the other regions.
    Type: Grant
    Filed: November 10, 1999
    Date of Patent: September 18, 2001
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Yasushi Miyasaka, Tatsuhiko Fujihira, Yasuhiko Ohnishi, Katsunori Ueno, Susumu Iwamoto
  • Publication number: 20010017393
    Abstract: A diode is provided which includes a first-conductivity-type cathode layer, a first-conductivity-type drift layer placed on the cathode region and having a lower concentration than the cathode layer, a generally ring-like second-conductivity-type ring region formed in the drift layer, second-conductivity-type anode region formed in the drift layer located inside the ring region, a cathode electrode formed in contact with the cathode layer, and an anode electrode formed in contact with the anode region, wherein the lowest resistivity of the second-conductivity-type anode region is at least {fraction (1/100)} of the resistivity of the drift layer, and the thickness of the anode region is smaller than the diffusion depth of the ring region.
    Type: Application
    Filed: February 26, 2001
    Publication date: August 30, 2001
    Applicant: Fuji Electric Co., Ltd
    Inventors: Tatsuhiko Fujihira, Yasushi Miyasaka
  • Patent number: 6221688
    Abstract: A diode is provided which includes a first-conductivity-type cathode layer, a first-conductivity-type drift layer placed on the cathode region and having a lower concentration than the cathode layer, a generally ring-like second-conductivity-type ring region formed in the drift layer, second-conductivity-type anode region formed in the drift layer located inside the ring region, a cathode electrode formed in contact with the cathode layer, and an anode electrode formed in contact with the anode region, wherein the lowest resistivity of the second-conductivity-type anode region is at least {fraction (1/100)} of the resistivity of the drift layer, and the thickness of the anode region is smaller than the diffusion depth of the ring region.
    Type: Grant
    Filed: August 30, 1999
    Date of Patent: April 24, 2001
    Assignee: Fuji Electric Co. Ltd.
    Inventors: Tatsuhiko Fujihira, Yasushi Miyasaka
  • Patent number: 6177712
    Abstract: A Schottky barrier diode is provided which has a substrate including a first-conductivity-type low concentration layer and a first-conductivity-type high concentration layer, and a guard ring region, comprising a second-conductivity-type diffusion layer having an impurity surface concentration of not greater than 5×1017/cm3, formed in the first-conductivity-type low concentration layer. The first-conductivity-type low concentration layer has a thickness large enough to prevent a depletion layer that appears in the low concentration layer upon application of the maximum reverse voltage from reaching the first-conductivity-type high concentration layer.
    Type: Grant
    Filed: December 10, 1997
    Date of Patent: January 23, 2001
    Assignee: Fuji Electric Co., Ltd.
    Inventor: Yasushi Miyasaka
  • Patent number: 6175143
    Abstract: A diode is provided which includes a first-conductivity-type cathode layer, a first-conductivity-type drift layer placed on the cathode region and having a lower concentration than the cathode layer, a generally ring-like second-conductivity-type ring region formed in the drift layer, second-conductivity-type anode region formed in the drift layer located inside the ring region, a cathode electrode formed in contact with the cathode layer, and an anode electrode formed in contact with the anode region, wherein the lowest resistivity of the second-conductivity-type anode region is at least {fraction (1/100)} of the resistivity of the drift layer, and the thickness of the anode region is smaller than the diffusion depth of the ring region.
    Type: Grant
    Filed: June 2, 1998
    Date of Patent: January 16, 2001
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Tatsuhiko Fujihira, Yasushi Miyasaka