Patents by Inventor Fumikazu Yamaki

Fumikazu Yamaki 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: 8629454
    Abstract: A semiconductor device includes: a nitride semiconductor layer; a source electrode, a gate electrode and a drain electrode; an insulating layer covering at least the gate electrode and a part of the nitride semiconductor layer; and a field plate on the insulating layer, a width of a region of the field plate between an edge of the field plate of a side of the drain electrode and an edge of the side face of the insulating layer covering a side face of the gate electrode of a side of the drain electrode being 0.1 ?m or more, a distance between an edge of the field plate and an edge of the drain electrode in a contact face between the nitride semiconductor layer and the drain electrode being 3.5 ?m or more, an operating frequency of the semiconductor device being 4 GHz or less.
    Type: Grant
    Filed: June 4, 2012
    Date of Patent: January 14, 2014
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventor: Fumikazu Yamaki
  • Patent number: 8604474
    Abstract: One type of a semiconductor device integrating with a monitoring device is disclosed. The device includes a plurality of gate fingers, two of which arranged in a center of the device has a space wider than a space between any other fingers to suppress the heat concentration on the center of the device. The monitoring region is arranged in this wider space to monitor the temperature dependence of the device.
    Type: Grant
    Filed: July 14, 2011
    Date of Patent: December 10, 2013
    Assignee: Sumitomo Electric Industries Ltd.
    Inventor: Fumikazu Yamaki
  • Patent number: 8592825
    Abstract: A semiconductor device and a process to form the semiconductor device are disclosed. The semiconductor device includes a Si substrate, active devices primarily made of nitride based compound semiconductor material, and passive devices. The Si substrate includes a via hole piercing from the back surface to the primary surface of the Si substrate. The active device is mounted on the primary surface so as to cover at least a portion of the via hole. The metal layer cover the whole back surface, inner surfaces of the via hole, and the back surface of the active device exposed in the via hole.
    Type: Grant
    Filed: July 25, 2011
    Date of Patent: November 26, 2013
    Assignee: Sumitomo Electric Industries Ltd.
    Inventor: Fumikazu Yamaki
  • Publication number: 20120305936
    Abstract: A semiconductor device includes: a nitride semiconductor layer; a source electrode, a gate electrode and a drain electrode; an insulating layer covering at least the gate electrode and a part of the nitride semiconductor layer; and a field plate on the insulating layer, a width of a region of the field plate between an edge of the field plate of a side of the drain electrode and an edge of the side face of the insulating layer covering a side face of the gate electrode of a side of the drain electrode being 0.1 ?m or more, a distance between an edge of the field plate and an edge of the drain electrode in a contact face between the nitride semiconductor layer and the drain electrode being 3.5 ?m or more, an operating frequency of the semiconductor device being 4 GHz or less.
    Type: Application
    Filed: June 4, 2012
    Publication date: December 6, 2012
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventor: Fumikazu YAMAKI
  • Patent number: 8242512
    Abstract: A compound semiconductor device includes: an electron transit layer made of GaN; a channel layer made of AlGaN; a source electrode, a gate electrode and a drain electrode that are provided on the channel layer; a cap layer that is provided at least between the source electrode and the gate electrode and between the gate electrode and the drain electrode and is made of GaN; a recess portion that is provided in the cap layer between the gate electrode and the drain electrode; and a thick portion that is provided in the cap layer between the recess portion and the drain electrode and has a thickness larger than the recess portion.
    Type: Grant
    Filed: January 10, 2011
    Date of Patent: August 14, 2012
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Fumikazu Yamaki, Kazutaka Inoue
  • Publication number: 20120025188
    Abstract: One type of a semiconductor device integrating with a monitoring device is disclosed. The device includes a plurality of gate fingers, two of which arranged in a center of the device has a space wider than a space between any other fingers to suppress the heat concentration on the center of the device. The monitoring region is arranged in this wider space to monitor the temperature dependence of the device.
    Type: Application
    Filed: July 14, 2011
    Publication date: February 2, 2012
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventor: Fumikazu YAMAKI
  • Publication number: 20120025204
    Abstract: A semiconductor device and a process to form the semiconductor device are disclosed. The semiconductor device includes a Si substrate, active devices primarily made of nitride based compound semiconductor material, and passive devices. The Si substrate includes a via hole piercing from the back surface to the primary surface of the Si substrate. The active device is mounted on the primary surface so as to cover at least a portion of the via hole. The metal layer cover the whole back surface, inner surfaces of the via hole, and the back surface of the active device exposed in the via hole.
    Type: Application
    Filed: July 25, 2011
    Publication date: February 2, 2012
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventor: Fumikazu YAMAKI
  • Publication number: 20110169014
    Abstract: A compound semiconductor device includes: an electron transit layer made of GaN; a channel layer made of AlGaN; a source electrode, a gate electrode and a drain electrode that are provided on the channel layer; a cap layer that is provided at least between the source electrode and the gate electrode and between the gate electrode and the drain electrode and is made of GaN; a recess portion that is provided in the cap layer between the gate electrode and the drain electrode; and a thick portion that is provided in the cap layer between the recess portion and the drain electrode and has a thickness larger than the recess portion.
    Type: Application
    Filed: January 10, 2011
    Publication date: July 14, 2011
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Fumikazu Yamaki, Kazutaka Inoue
  • Patent number: 6982441
    Abstract: A semiconductor device includes a compound semiconductor substrate having a resistivity less than 1.0×108 Ohm-cm at least at one surface thereof, a buffer layer formed on the compound semiconductor substrate and having a super lattice structure, and an active layer formed on the buffer layer and having an active element formed therein.
    Type: Grant
    Filed: January 4, 2002
    Date of Patent: January 3, 2006
    Assignee: Fujitsu Quantum Devices Limited
    Inventors: Fumikazu Yamaki, Takeshi Igarashi
  • Publication number: 20020088994
    Abstract: A semiconductor device includes a compound semiconductor substrate having a resistivity less than 1.0×108 Ohm-cm at least at one surface thereof, a buffer layer formed on the compound semiconductor substrate and having a super lattice structure, and an active layer formed on the buffer layer and having an active element formed therein.
    Type: Application
    Filed: January 4, 2002
    Publication date: July 11, 2002
    Applicant: Fujitsu Quantum Devices Limited
    Inventors: Fumikazu Yamaki, Takeshi Igarashi