Patents by Inventor Ichiro Omura

Ichiro Omura 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: 7102179
    Abstract: A power semiconductor device includes a first semiconductor layer, a second semiconductor layer of a first conductivity type, first and second main electrodes, a control electrode and a third semiconductor layer. The second semiconductor layer is formed on the first semiconductor layer. The first and second main electrodes are formed on the second semiconductor layer separately from each other. The control electrode is formed on the second semiconductor layer between the first and second main electrodes. The third semiconductor layer is formed on the second semiconductor layer between the control electrode and the second main electrode.
    Type: Grant
    Filed: November 12, 2004
    Date of Patent: September 5, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Wataru Saito, Ichiro Omura, Hiromichi Ohashi
  • Publication number: 20060170003
    Abstract: A multi-layered structure in which a p-3C-SiC layer 102 is formed above a p-Si substrate 101 is formed, above which an I-GaN layer (channel layer) 103, an n-AlGaN layer (barrier layer) 104 are formed. A source electrode 201, a drain electrode 202, and a gate electrode 203 are formed above the n-AlGaN layer 104. The source electrode 201 and the drain electrode 202 form an ohmic contact with the n-AlGaN layer 104. The gate electrode 203 forms a Schottky junction with the n-AlGaN layer 104.
    Type: Application
    Filed: June 10, 2005
    Publication date: August 3, 2006
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Wataru Saito, Ichiro Omura, Kouhei Morizuka
  • Publication number: 20060157813
    Abstract: A power semiconductor device has a first main electrode formed along a surface of a substrate, a first semiconductor layer of first conductive type electrically connected to the first main electrode, a cyclic structure section which is formed on the first semiconductor layer and has second semiconductor layers of first conductive type and third semiconductor layers of second conductive type alternately and cyclically formed along the surface of the substrate, a fourth semiconductor layer of second conductive type selectively formed on a part of the second and third semiconductor layers, a fifth semiconductor layer of first conductive type selectively formed on the fourth semiconductor layer, a second main electrode contacted the fourth and fifth semiconductor layers, a control electrode disposed adjacent via a first insulating film on the second, fourth and fifth semiconductor layers, and a depletion layer blocking section which is formed outside of the cyclic structure section and prevents a depletion layer
    Type: Application
    Filed: October 17, 2005
    Publication date: July 20, 2006
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Wataru Saito, Ichiro Omura
  • Patent number: 7078740
    Abstract: A power semiconductor device includes trenches disposed in a first base layer of a first conductivity type at intervals to partition main and dummy cells, at a position remote from a collector layer of a second conductivity type. In the main cell, a second base layer of the second conductivity type, and an emitter layer of the first conductivity type are disposed. In the dummy cell, a buffer layer of the second conductivity type is disposed. A gate electrode is disposed, through a gate insulating film, in a trench adjacent to the main cell. A buffer resistor having an infinitely large resistance value is inserted between the buffer layer and emitter electrode. The dummy cell is provided with an inhibiting structure to reduce carriers of the second conductivity type to flow to and accumulate in the buffer layer from the collector layer.
    Type: Grant
    Filed: May 12, 2004
    Date of Patent: July 18, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masakazu Yamaguchi, Hideaki Ninomiya, Ichiro Omura, Tomoki Inoue
  • Patent number: 7075125
    Abstract: A power semiconductor device includes a first semiconductor layer of non-doped AlXGa1?XN (0?X?1), and a second semiconductor layer of non-doped or n-type AlYGa1?YN (0?Y?1, X<Y) disposed on the first semiconductor layer. Source and drain electrodes are disposed separately from each other, and electrically connected to the second semiconductor layer. A gate electrode is disposed on the second semiconductor layer between the source and drain electrodes. An insulating film covers the second semiconductor layer between the gate and drain electrodes. A first field plate electrode is disposed on the insulating film and electrically connected to the gate electrode. A second field plate electrode is disposed on the insulating film and electrically connected to the source electrode.
    Type: Grant
    Filed: March 23, 2004
    Date of Patent: July 11, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Wataru Saito, Ichiro Omura
  • Publication number: 20060145230
    Abstract: A semiconductor element of this invention includes a drift layer of a first conductivity type formed on a semiconductor substrate of the first conductivity type, a well layer of a second conductivity type selectively formed in the surface of the drift layer, a source layer of the first conductivity type selectively formed in the surface of the well layer, a trench formed to reach at least the inside of the drift layer from the surface of the source layer through the well layer, a buried electrode formed in the trench through a first insulating film, and a control electrode formed on the drift layer, the well layer, and the source layer through a second insulating film.
    Type: Application
    Filed: December 5, 2005
    Publication date: July 6, 2006
    Inventors: Ichiro Omura, Wataru Saito, Tsuneo Ogura, Hiromichi Ohashi, Yoshihiko Saito, Kenichi Tokano
  • Publication number: 20060145298
    Abstract: According to the present invention, there is provided a semiconductor device including a MOSFET, comprising: a second-conductivity-type semiconductor layer selectively formed in one surface portion of a first first-conductivity-type semiconductor layer; a second first-conductivity-type semiconductor layer selectively formed in a surface portion of said second-conductivity-type semiconductor layer; a first main electrode electrically connected to said second first-conductivity-type semiconductor layer and second-conductivity-type semiconductor layer; a second main electrode electrically connected to the other surface of said first first-conductivity-type semiconductor layer; and a control electrode formed on the surfaces of said second first-conductivity-type semiconductor layer, second-conductivity-type semiconductor layer, and first first-conductivity-type semiconductor layer via an insulating film, and a junction between said second main electrode and first first-conductivity-type semiconductor layer is a S
    Type: Application
    Filed: December 8, 2005
    Publication date: July 6, 2006
    Applicant: Kabushiki Kaisha Toshiba
    Inventor: Ichiro Omura
  • Publication number: 20060145290
    Abstract: A semiconductor device includes a diffusion area formed in a semiconductor layer of a first conductive type. The diffusion area comprises first and second impurity diffusion areas of the first and second conductive types, respectively. The diffusion area has a first and second areas which are defined by an impurity concentration of the first and second impurity diffusion areas. A junction between the first and second area is formed in a portion in which the first and second impurity diffusion areas overlap each other. A period of the impurity concentration, in a planar direction of the semiconductor layer, of the first or second area is smaller than the maximum width, in the planar direction of the semiconductor layer, of the first and second impurity diffusion areas constituting the first or second area.
    Type: Application
    Filed: December 6, 2005
    Publication date: July 6, 2006
    Inventors: Hideki Okumura, Hitoshi Kobayashi, Masanobu Tsuchitani, Akihiko Osawa, Wataru Saito, Masakazu Yamaguchi, Ichiro Omura
  • Publication number: 20060138454
    Abstract: A semiconductor device includes: a first semiconductor layer represented by a composition formula AlxGa1-xN (0?x?1); a first conductivity type or non-doped second semiconductor layer represented by a composition formula AlyGa1-yN (0?y?1, x<y) and formed on the first semiconductor layer; a second conductivity type third semiconductor layer represented by a composition formula AlxGa1-xN (0?x?1) and selectively formed on the second semiconductor layer; a gate electrode formed on the third semiconductor layer; a source electrode electrically connected to the second semiconductor layer; and a drain electrode electrically connected to the second semiconductor layer. The distance between the drain electrode and the third semiconductor layer is longer than the distance between the source electrode and the third semiconductor layer.
    Type: Application
    Filed: February 15, 2006
    Publication date: June 29, 2006
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Wataru Saito, Ichiro Omura
  • Patent number: 7067870
    Abstract: A semiconductor element of this invention includes a drift layer of a first conductivity type formed on a semiconductor substrate of the first conductivity type, a well layer of a second conductivity type selectively formed in the surface of the drift layer, a source layer of the first conductivity type selectively formed in the surface of the well layer, a trench formed to reach at least the inside of the drift layer from the surface of the source layer through the well layer, a buried electrode formed in the trench through a first insulating film, and a control electrode formed on the drift layer, the well layer, and the source layer through a second insulating film.
    Type: Grant
    Filed: February 3, 2004
    Date of Patent: June 27, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Ichiro Omura, Wataru Saito, Tsuneo Ogura, Hiromichi Ohashi, Yoshihiko Saito, Kenichi Tokano
  • Publication number: 20060131644
    Abstract: A power semiconductor device includes second semiconductor layers of a first conductivity type and third semiconductor layers of a second conductivity type alternately disposed on a first semiconductor layer of the first conductivity type. The device further includes fourth semiconductor layers of the second conductivity type disposed in contact with upper portions of the third semiconductor layers between the second semiconductor layers, and fifth semiconductor layers of the first conductivity type formed in surfaces of the fourth semiconductor layers. The first semiconductor layer is lower in impurity concentration of the first conductivity type than each second semiconductor layer. The third semiconductor layer includes a fundamental portion and an impurity-amount-larger portion formed locally in a depth direction and higher in impurity amount than the fundamental portion.
    Type: Application
    Filed: April 29, 2005
    Publication date: June 22, 2006
    Inventors: Wataru Saito, Ichiro Omura
  • Patent number: 7049658
    Abstract: Disclosed is a power semiconductor device, including a first semiconductor layer of a first conductivity type, a second semiconductor layer of the first conductivity type and a third semiconductor layer of a second conductivity type which are alternately and laterally arranged on the first semiconductor layer and, a fourth semiconductor layer of the second conductivity type selectively formed in the surface regions of the second and third semiconductor layers, a fifth semiconductor layer of the first conductivity type selectively formed in the surface region of the fourth semiconductor layer, and a control electrode formed on the surfaces of the second, fourth and fifth semiconductor layers, in which a layer thickness ratio A is given by the expression: 0<A=t/(t+d)?0.72 where t is the thickness of the first semiconductor layer, and d is the thickness of the second semiconductor layer.
    Type: Grant
    Filed: June 25, 2003
    Date of Patent: May 23, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Wataru Saito, Ichiro Omura, Tsuneo Ogura
  • Publication number: 20060102290
    Abstract: A wafer supporting plate is formed of a glass or a resin which can permeate ultraviolet rays and has a nearly disk shape. An outer diameter of the wafer supporting plate is larger than that of the semiconductor wafer which is supported. In the wafer supporting plate, a plurality of openings are formed to correspond to plural through holes of the semiconductor wafer. The opening has an open area larger than an open area of the through hole, that is, has a larger diameter.
    Type: Application
    Filed: September 9, 2005
    Publication date: May 18, 2006
    Inventors: Susumu Harada, Chiaki Takubo, Kenji Takahashi, Hideo Aoki, Hideo Numata, Hisashi Kaneko, Hirokazu Ezawa, Mie Matsuo, Hiroshi Ikenoue, Ichiro Omura
  • Patent number: 7038252
    Abstract: A semiconductor device includes: a first semiconductor layer represented by a composition formula AlxGa1-xN (0?x?1) a first conductivity type or non-doped second semiconductor layer represented by a composition formula AlyGa1-yN (0?y?1, x<y) and formed on the first semiconductor layer; a second conductivity type third semiconductor layer represented by a composition formula AlxGa1-xN (0?x?1) and selectively formed on the second semiconductor layer; a gate electrode formed on the third semiconductor layer; a source electrode electrically connected to the second semiconductor layer; and a drain electrode electrically connected to the second semiconductor layer. The distance between the drain electrode and the third semiconductor layer is longer than the distance between the source electrode and the third semiconductor layer.
    Type: Grant
    Filed: April 26, 2004
    Date of Patent: May 2, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Wataru Saito, Ichiro Omura
  • Publication number: 20060071271
    Abstract: A semiconductor device which is compact and thin in size, low in resistance of a current path and parasitic inductance and excellent in reliability is provided. This semiconductor device comprises a semiconductor substrate, a first main electrode which is formed on a front surface of the semiconductor substrate, a second main electrode which is formed on a rear surface of the semiconductor substrate, and a conducting portion which is formed in a direction to pierce through the semiconductor substrate, wherein the second main electrode is extracted to the front surface of the semiconductor substrate via the conducting portion. And, the conducting portion is a through via which has a through hole formed through the semiconductor substrate in its thickness direction and a conductive portion which is formed in the through hole and connected to the second main electrode.
    Type: Application
    Filed: September 21, 2005
    Publication date: April 6, 2006
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Ichiro Omura, Kenji Takahashi, Chiaki Takubo, Hideo Aoki, Hideo Numata, Mie Matsuo, Hirokazu Ezawa, Susumu Harada, Hisashi Kaneko, Hiroshi Ikenoue, Kenichi Matsushita
  • Publication number: 20060071267
    Abstract: Disclosed is a power semiconductor device, including a first semiconductor layer of a first conductivity type, a second semiconductor layer of the first conductivity type and a third semiconductor layer of a second conductivity type which are alternately and laterally arranged on the first semiconductor layer and, a fourth semiconductor layer of the second conductivity type selectively formed in the surface regions of the second and third semiconductor layers, a fifth semiconductor layer of the first conductivity type selectively formed in the surface region of the fourth semiconductor layer, and a control electrode formed on the surfaces of the second, fourth and fifth semiconductor layers, in which a layer thickness ratio A is given by the expression: 0<A=t/(t+d)?0.72 where t is the thickness of the first semiconductor layer, and d is the thickness of the second semiconductor layer.
    Type: Application
    Filed: November 3, 2005
    Publication date: April 6, 2006
    Inventors: Wataru Saito, Ichiro Omura, Tsuneo Ogura
  • Publication number: 20060055050
    Abstract: A semiconductor device comprises a semiconductor substrate having an through hole, a first insulation resin layer formed on an inner surface of the through hole, a second insulation resin layer formed on at least one of front and rear surfaces of the semiconductor substrate, and a first conductor layer formed in the through hole to connect at least both front and rear surfaces of the semiconductor substrate and insulated from the inner surface of the through hole with the first insulation resin layer. A second conductor layer (wiring pattern) which is electrically connected to the first conductor layer in the through hole is further provided on the second insulation resin layer. The conductor layer formed in the through hole and constituting a connecting plug has a high insulation reliability. Therefore, a semiconductor device suitable for a multi-chip package and the like can be obtained.
    Type: Application
    Filed: September 9, 2005
    Publication date: March 16, 2006
    Inventors: Hideo Numata, Hirokazu Ezawa, Chiaki Takubo, Kenji Takahashi, Hideo Aoki, Susumu Harada, Hisashi Kaneko, Hiroshi Ikenoue, Mie Matsuo, Ichiro Omura
  • Publication number: 20060055432
    Abstract: A semiconductor module comprises a mounting board. A plurality of power switching device chips are mounted on the mounting board by flip-chip bonding. The chip has an upper surface and a lower surface and is configured to face the upper surface toward the mounting board. A drive IC chip is mounted on the mounting board by flip-chip bonding. The drive IC chip is operative to drive gates of transistors formed in the plurality of power switching device chips. A plurality of heat sink members are located on the lower surfaces of the plurality of power switching device chips, respectively. A resinous member is provided to seal the plurality of power switching device chips and the drive IC chip in a single package.
    Type: Application
    Filed: August 31, 2005
    Publication date: March 16, 2006
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kazuo Shimokawa, Takashi Koyanagawa, Masako Ooishi, Tatsuya Yamada, Osamu Usuda, Yoshiki Endo, Taiki Miura, Masaki Toyoshima, Ichiro Omura, Akio Nakagawa, Kenichi Matsushita, Yusuke Kawaguchi, Haruki Arai, Hiroshi Takei, Tomohiro Kawano, Noriaki Yoshikawa, Morio Takahashi, Yasuhito Saito, Masahiro Urase
  • Publication number: 20060054924
    Abstract: A nitride-based semiconductor device includes a first semiconductor layer consisting essentially of a nitride-based semiconductor, and a second semiconductor layer disposed on the first semiconductor layer and consisting essentially of a non-doped or first conductivity type nitride-based semiconductor. The first and second semiconductor layers forms a hetero-interface. A gate electrode is disposed on the second semiconductor layer. First and second trenches are formed in a surface of the second semiconductor layer at positions sandwiching the gate electrode. Third and fourth semiconductor layers of the first conductivity type are respectively formed in surfaces of the first and second trenches and each consist essentially of a diffusion layer having a resistivity lower than the first and second semiconductor layers. Source and drain electrodes are electrically connected to the third and fourth semiconductor layers, respectively.
    Type: Application
    Filed: December 20, 2004
    Publication date: March 16, 2006
    Inventors: Wataru Saito, Ichiro Omura
  • Publication number: 20060043501
    Abstract: In a nitride semiconductor device according to one embodiment of the invention, a p-type gallium nitride (GaN) layer electrically connected to a source electrode and extending and projecting to a drain electrode side with respect to a gate electrode is formed on an undoped or n-type aluminum gallium nitride (AlGaN) layer serving as a barrier layer.
    Type: Application
    Filed: April 20, 2005
    Publication date: March 2, 2006
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Wataru Saito, Ichiro Omura