Patents by Inventor Kenji Nukui

Kenji Nukui 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: 9620616
    Abstract: A method of manufacturing a semiconductor device includes laminating and forming an electron transit layer, an electron supplying layer, an etching stop layer, and a p-type film on a substrate sequentially, the p-type film being formed of a nitride semiconductor material that includes Al doped with an impurity element that attains p-type, the etching stop layer being formed of a material that includes GaN, removing the p-type film in an area except an area where a gate electrode is to be formed, by dry etching to form a p-type layer in the area where the gate electrode is to be formed, the dry etching being conducted while plasma emission in the dry etching is observed, the dry etching being stopped after the dry etching is started and plasma emission originating from Al is not observed, and forming the gate electrode on the p-type layer.
    Type: Grant
    Filed: December 24, 2014
    Date of Patent: April 11, 2017
    Assignee: Transphorm Japan, Inc.
    Inventors: Atsushi Yamada, Kenji Nukui
  • Patent number: 9142658
    Abstract: A compound semiconductor device includes: a compound semiconductor layer; and a gate electrode formed above the compound semiconductor layer; and a source electrode and a drain electrode formed on both sides of the gate electrode, on the compound semiconductor layer, wherein the source electrode has a plurality of bottom surfaces along transit electrons out of contact surfaces with the compound semiconductor layer, and the plural bottom surfaces are located at different distances from the transit electrons, with the bottom surface closer to the gate electrode being more apart from the transit electrons.
    Type: Grant
    Filed: September 20, 2013
    Date of Patent: September 22, 2015
    Assignee: Transphorm Japan, Inc.
    Inventors: Toshihide Kikkawa, Kenji Nukui
  • Patent number: 9099545
    Abstract: A compound semiconductor device includes a substrate; a compound semiconductor layer formed on the substrate; a first insulating film formed on the compound semiconductor layer; a second insulating film formed on the first insulating film; and a gate electrode, a source electrode, and a drain electrode, each being formed on the compound semiconductor layer, wherein the gate electrode is formed of a first opening filled with a first conductive material via at least a gate insulator, and the first opening is formed in the first insulating film and configured to partially expose the compound semiconductor layer, and wherein the source electrode and the drain electrode are formed of a pair of second openings filled with at least a second conductive material, and the second openings are formed in at least the second insulating film and the first insulating film and configured to partially expose the compound semiconductor layer.
    Type: Grant
    Filed: September 23, 2013
    Date of Patent: August 4, 2015
    Assignee: Transphorm Japan, Inc.
    Inventors: Shinichi Akiyama, Kenji Nukui, Mutsumi Katou, Yoshitaka Watanabe, Tetsuya Itou, Yoichi Fujisawa, Toshiya Sato, Tsutomu Hosoda, Yuuichi Satou
  • Publication number: 20150137184
    Abstract: A method of manufacturing a semiconductor device includes laminating and forming an electron transit layer, an electron supplying layer, an etching stop layer, and a p-type film on a substrate sequentially, the p-type film being formed of a nitride semiconductor material that includes Al doped with an impurity element that attains p-type, the etching stop layer being formed of a material that includes GaN, removing the p-type film in an area except an area where a gate electrode is to be formed, by dry etching to form a p-type layer in the area where the gate electrode is to be formed, the dry etching being conducted while plasma emission in the dry etching is observed, the dry etching being stopped after the dry etching is started and plasma emission originating from Al is not observed, and forming the gate electrode on the p-type layer.
    Type: Application
    Filed: December 24, 2014
    Publication date: May 21, 2015
    Inventors: Atsushi Yamada, Kenji Nukui
  • Patent number: 8957453
    Abstract: A method of manufacturing a semiconductor device includes laminating and forming an electron transit layer, an electron supplying layer, an etching stop layer, and a p-type film on a substrate sequentially, the p-type film being formed of a nitride semiconductor material that includes Al doped with an impurity element that attains p-type, the etching stop layer being formed of a material that includes GaN, removing the p-type film in an area except an area where a gate electrode is to be formed, by dry etching to form a p-type layer in the area where the gate electrode is to be formed, the dry etching being conducted while plasma emission in the dry etching is observed, the dry etching being stopped after the dry etching is started and plasma emission originating from Al is not observed, and forming the gate electrode on the p-type layer.
    Type: Grant
    Filed: July 30, 2013
    Date of Patent: February 17, 2015
    Assignee: Transphorm Japan, Inc.
    Inventors: Atsushi Yamada, Kenji Nukui
  • Publication number: 20140091365
    Abstract: A compound semiconductor device includes: a compound semiconductor layer; and a gate electrode formed above the compound semiconductor layer; and a source electrode and a drain electrode formed on both sides of the gate electrode, on the compound semiconductor layer, wherein the source electrode has a plurality of bottom surfaces along transit electrons out of contact surfaces with the compound semiconductor layer, and the plural bottom surfaces are located at different distances from the transit electrons, with the bottom surface closer to the gate electrode being more apart from the transit electrons.
    Type: Application
    Filed: September 20, 2013
    Publication date: April 3, 2014
    Applicants: FUJITSU SEMICONDUCTOR LIMITED, FUJITSU LIMITED
    Inventors: Toshihide Kikkawa, Kenji Nukui
  • Publication number: 20140091319
    Abstract: A method of manufacturing a semiconductor device includes laminating and forming an electron transit layer, an electron supplying layer, an etching stop layer, and a p-type film on a substrate sequentially, the p-type film being formed of a nitride semiconductor material that includes Al doped with an impurity element that attains p-type, the etching stop layer being formed of a material that includes GaN, removing the p-type film in an area except an area where a gate electrode is to be formed, by dry etching to form a p-type layer in the area where the gate electrode is to be formed, the dry etching being conducted while plasma emission in the dry etching is observed, the dry etching being stopped after the dry etching is started and plasma emission originating from Al is not observed, and forming the gate electrode on the p-type layer.
    Type: Application
    Filed: July 30, 2013
    Publication date: April 3, 2014
    Applicants: Fujitsu Semiconductor Limited, Fujitsu Limited
    Inventors: Atsushi Yamada, KENJI NUKUI
  • Publication number: 20140021513
    Abstract: A compound semiconductor device includes a substrate; a compound semiconductor layer formed on the substrate; a first insulating film formed on the compound semiconductor layer; a second insulating film formed on the first insulating film; and a gate electrode, a source electrode, and a drain electrode, each being formed on the compound semiconductor layer, wherein the gate electrode is formed of a first opening filled with a first conductive material via at least a gate insulator, and the first opening is formed in the first insulating film and configured to partially expose the compound semiconductor layer, and wherein the source electrode and the drain electrode are formed of a pair of second openings filled with at least a second conductive material, and the second openings are formed in at least the second insulating film and the first insulating film and configured to partially expose the compound semiconductor layer.
    Type: Application
    Filed: September 23, 2013
    Publication date: January 23, 2014
    Applicant: FUJITSU SEMICONDUCTOR LIMITED
    Inventors: Shinichi AKIYAMA, Kenji NUKUI, Mutsumi KATOU, Yoshitaka WATANABE, Tetsuya ITOU, Yoichi FUJISAWA, Toshiya SATO, Tsutomu HOSODA, Yuuichi SATOU
  • Patent number: 8569124
    Abstract: A compound semiconductor device includes a substrate; a compound semiconductor layer formed on the substrate; a first insulating film formed on the compound semiconductor layer; a second insulating film formed on the first insulating film; and a gate electrode, a source electrode, and a drain electrode, each being formed on the compound semiconductor layer, wherein the gate electrode is formed of a first opening filled with a first conductive material via at least a gate insulator, and the first opening is formed in the first insulating film and configured to partially expose the compound semiconductor layer, and wherein the source electrode and the drain electrode are formed of a pair of second openings filled with at least a second conductive material, and the second openings are formed in at least the second insulating film and the first insulating film and configured to partially expose the compound semiconductor layer.
    Type: Grant
    Filed: April 19, 2011
    Date of Patent: October 29, 2013
    Assignee: Fujitsu Semiconductor Limited
    Inventors: Shinichi Akiyama, Kenji Nukui, Mutsumi Katou, Yoshitaka Watanabe, Tetsuya Itou, Yoichi Fujisawa, Toshiya Sato, Tsutomu Hosoda, Yuuichi Satou
  • Publication number: 20110272742
    Abstract: A compound semiconductor device includes a substrate; a compound semiconductor layer formed on the substrate; a first insulating film formed on the compound semiconductor layer; a second insulating film formed on the first insulating film; and a gate electrode, a source electrode, and a drain electrode, each being formed on the compound semiconductor layer, wherein the gate electrode is formed of a first opening filled with a first conductive material via at least a gate insulator, and the first opening is formed in the first insulating film and configured to partially expose the compound semiconductor layer, and wherein the source electrode and the drain electrode are formed of a pair of second openings filled with at least a second conductive material, and the second openings are formed in at least the second insulating film and the first insulating film and configured to partially expose the compound semiconductor layer.
    Type: Application
    Filed: April 19, 2011
    Publication date: November 10, 2011
    Applicant: FUJITSU SEMICONDUCTOR LIMITED
    Inventors: Shinichi AKIYAMA, Kenji Nukui, Mutsumi Katou, Yoshitaka Watanabe, Tetsuya Itou, Yoichi Fujisawa, Toshiya Sato, Tsutomu Hosoda, Yuuichi Satou
  • Patent number: 7682983
    Abstract: A manufacturing method of an electronic device, includes the steps of: implanting P (phosphorous) ions into a substrate semiconductor region made of Si or SiGe by using a resist as a mask; ashing the resist while it is heated in a vacuum environment; and taking out the substrate, the substrate being ashing processed so that a temperature of the substrate is equal to or less than 130° C.
    Type: Grant
    Filed: July 17, 2006
    Date of Patent: March 23, 2010
    Assignee: Fujitsu Microelectronics Limited
    Inventors: Hikaru Kokura, Kenji Nukui, Shinji Fukuta, Tadashi Oshima, Fukashi Harada, Tatsuro Kawabata
  • Publication number: 20070173066
    Abstract: A manufacturing method of an electronic device, includes the steps of: implanting P (phosphorous) ions into a substrate semiconductor region made of Si or SiGe by using a resist as a mask; ashing the resist while it is heated in a vacuum environment; and taking out the substrate, the substrate being ashing processed so that a temperature of the substrate is equal to or less than 130° C.
    Type: Application
    Filed: July 17, 2006
    Publication date: July 26, 2007
    Applicant: FUJITSU LIMITED
    Inventors: Hikaru Kokura, Kenji Nukui, Shinji Fukuta, Tadashi Oshima, Fukashi Harada, Tatsuro Kawabata
  • Patent number: 6232663
    Abstract: A semiconductor device and a method of fabricating thereof, including an insulator layer having alternately layered insulator films and boundary layers, wherein the boundary layers are more dense than the insulator films to prevent expansion and elongation of string-like defects across the boundary layers. The method includes mixing a nitrogen containing gas and a silane group gas to form an insulator film; temporarily stopping a flow of the silane group gas for approximately one to fifteen seconds to form a boundary layer over the insulator film; restarting the flow of the silane group gas; and repeating the steps of temporarily stopping and restarting for a predetermined number of times to form the plurality of alternately layered insulator films and boundary layers. The plurality of alternately layered insulator films and boundary layers is also etched at an etching rate for the insulator films greater than an etching rate for the boundary layers to form a step-shaped sloped opening.
    Type: Grant
    Filed: August 1, 1997
    Date of Patent: May 15, 2001
    Assignees: Fujitsu Limited, Advanced Micro Devices, Inc., Fujitsu AMD, Semiconductor Limited
    Inventors: Toshio Taniguchi, Kenji Nukui, Ibrahim Burki, Richard Huang, Simon Chan, Kazunori Imaoka, Kazutoshi Mochizuki