Patents by Inventor Shigeo Tooi

Shigeo Tooi 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: 8129818
    Abstract: The present invention is a power device includes, a first conductive type semiconductor substrate, a second conductive type base region formed on a surface of the semiconductor substrate, a second conductive type collector region formed on a rear surface of the semiconductor substrate, a first conductive type emitter region formed on a surface of the base region, a trench gate formed via a gate insulating film in a first trench groove formed in the base region so as to penetrate the emitter region, a dent formed in the base region in proximity to the emitter region, a second conductive type contact layer formed on an inner wall of the dent, having a higher dopant density than that of the base region, a dummy trench formed via a dummy trench insulating film in a second trench groove formed at a bottom of the dent, and an emitter electrode electrically connected to the emitter region, the contact layer and the dummy trench, wherein the trench gate and the dummy trench reach the semiconductor substrate.
    Type: Grant
    Filed: October 14, 2008
    Date of Patent: March 6, 2012
    Assignee: Mitsubishi Electric Corporation
    Inventors: Shigeo Tooi, Tetsujiro Tsunoda
  • Publication number: 20110133312
    Abstract: The present invention is a power device includes, a first conductive type semiconductor substrate, a second conductive type base region formed on a surface of the semiconductor substrate, a second conductive type collector region formed on a rear surface of the semiconductor substrate, a first conductive type emitter region formed on a surface of the base region, a trench gate formed via a gate insulating film in a first trench groove formed in the base region so as to penetrate the emitter region, a dent formed in the base region in proximity to the emitter region, a second conductive type contact layer formed on an inner wall of the dent, having a higher dopant density than that of the base region, a dummy trench formed via a dummy trench insulating film in a second trench groove formed at a bottom of the dent, and an emitter electrode electrically connected to the emitter region, the contact layer and the dummy trench, wherein the trench gate and the dummy trench reach the semiconductor substrate.
    Type: Application
    Filed: October 14, 2008
    Publication date: June 9, 2011
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Shigeo Tooi, Tetsujiro Tsunoda
  • Patent number: 7772669
    Abstract: Second diffusion layers to be guard rings of a second conductivity type are formed on the major surface of a semiconductor substrate of a first conductivity type in a guard ring region. An insulating film is formed on these second diffusion layers. The semiconductor device has a structure wherein a conductive film is formed on the insulating film between adjacent electrodes among a first surface electrode, second surface electrodes, and a third surface electrode.
    Type: Grant
    Filed: October 2, 2006
    Date of Patent: August 10, 2010
    Assignee: Mitsubishi Electric Corporation
    Inventors: Shigeo Tooi, Tetsujiro Tsunoda
  • Publication number: 20070278672
    Abstract: Second diffusion layers to be guard rings of a second conductivity type are formed on the major surface of a semiconductor substrate of a first conductivity type in a guard ring region. An insulating film is formed on these second diffusion layers. The semiconductor device has a structure wherein a conductive film is formed on the insulating film between adjacent electrodes among a first surface electrode, second surface electrodes, and a third surface electrode.
    Type: Application
    Filed: October 2, 2006
    Publication date: December 6, 2007
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Shigeo Tooi, Tetsujiro Tsunoda
  • Patent number: 7057298
    Abstract: A switching chip using silicon as the base material is located on the upper surface of a cooling mechanism formed of a heat sink, an insulating substrate and a conductive plate, with a first conductive layer sandwiched in between. Further, a diode chip having a smaller area than a cathode electrode and using a wide gap semiconductor as the base material is located on the cathode electrode which has a smaller area than an anode electrode, with a second conductive layer sandwiched in between. A closed container encloses every structural component except an exposed portion of a bottom surface in the interior space.
    Type: Grant
    Filed: December 9, 2004
    Date of Patent: June 6, 2006
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Masayoshi Hirao, Katsumi Satou, Shigeo Tooi, Kazushige Matsuo
  • Publication number: 20050098876
    Abstract: A switching chip using silicon as the base material is located on the upper surface of a cooling mechanism formed of a heat sink, an insulating substrate and a conductive plate, with a first conductive layer sandwiched in between. Further, a diode chip having a smaller area than a cathode electrode and using a wide gap semiconductor as the base material is located on the cathode electrode which has a smaller area than an anode electrode, with a second conductive layer sandwiched in between. A closed container encloses every structural component except an exposed portion of a bottom surface in the interior space.
    Type: Application
    Filed: December 9, 2004
    Publication date: May 12, 2005
    Inventors: Masayoshi Hirao, Katsumi Satou, Shigeo Tooi, Kazushige Matsuo
  • Patent number: 6861730
    Abstract: A switching chip (101) using silicon as the base material is located on the upper surface of a cooling mechanism formed of a heat sink (115), an insulating substrate (114) and a conductive plate (108), with a first conductive layer (109A) sandwiched in between. Further, a diode chip (102) having a smaller area than a cathode electrode (103) and using a wide gap semiconductor as the base material is located on the cathode electrode (103) which has a smaller area than an anode electrode (105), with a second conductive layer (109B) sandwiched in between. A closed container (117) encloses every structural component except an exposed portion of a bottom surface (115BS) in the interior space.
    Type: Grant
    Filed: February 26, 2004
    Date of Patent: March 1, 2005
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Masayoshi Hirao, Katsumi Satou, Shigeo Tooi, Kazushige Matsuo
  • Patent number: 6831351
    Abstract: A switching chip (101) using silicon as the base material is located on the upper surface of a cooling mechanism formed of a heat sink (115), an insulating substrate (114) and a conductive plate (108), with a first conductive layer (109A) sandwiched in between. Further, a diode chip (102) having a smaller area than a cathode electrode (103) and using a wide gap semiconductor as the base material is located on the cathode electrode (103) which has a smaller area than an anode electrode (105), with a second conductive layer (109B) sandwiched in between. A closed container (117) encloses every structural component except an exposed portion of a bottom surface (115BS) in the interior space.
    Type: Grant
    Filed: August 1, 2002
    Date of Patent: December 14, 2004
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Masayoshi Hirao, Katsumi Satou, Shigeo Tooi, Kazushige Matsuo
  • Publication number: 20040164403
    Abstract: A switching chip (101) using silicon as the base material is located on the upper surface of a cooling mechanism formed of a heat sink (115), an insulating substrate (114) and a conductive plate (108), with a first conductive layer (109A) sandwiched in between. Further, a diode chip (102) having a smaller area than a cathode electrode (103) and using a wide gap semiconductor as the base material is located on the cathode electrode (103) which has a smaller area than an anode electrode (105), with a second conductive layer (109B) sandwiched in between. A closed container (117) encloses every structural component except an exposed portion of a bottom surface (115BS) in the interior space.
    Type: Application
    Filed: February 26, 2004
    Publication date: August 26, 2004
    Applicant: MITSUBISHI DENKI KABUSHIKI KAISHA
    Inventors: Masayoshi Hirao, Katsumi Satou, Shigeo Tooi, Kazushige Matsuo
  • Patent number: 6649995
    Abstract: A Schottky diode that achieves a predetermined reverse-direction breakdown voltage even if a state of a surface in a vicinity of a Schottky junction interface changes due to a welding of a bonding wire. The semiconductor device having the Schottky junction includes a semiconductor substrate of a first conductivity type. A well region of a second conductivity type is formed in a top surface of the semiconductor substrate. A Schottky electrode is formed on the top surface of the semiconductor substrate. A connecting conductive member is electrically connected to the Schottky electrode. The connecting conductive member is selectively connected to the Schottky electrode above the well region such that a connection surface between the connecting conductive member and the Schottky electrode is not extended above a Schottky junction between the Schottky electrode and the semiconductor substrate of the first conductivity type.
    Type: Grant
    Filed: April 22, 2002
    Date of Patent: November 18, 2003
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Shigeo Tooi, Katsumi Satoh
  • Publication number: 20030155644
    Abstract: A switching chip (101) using silicon as the base material is located on the upper surface of a cooling mechanism formed of a heat sink (115), an insulating substrate (114) and a conductive plate (108), with a first conductive layer (109A) sandwiched in between. Further, a diode chip (102) having a smaller area than a cathode electrode (103) and using a wide gap semiconductor as the base material is located on the cathode electrode (103) which has a smaller area than an anode electrode (105), with a second conductive layer (109B) sandwiched in between. A closed container (117) encloses every structural component except an exposed portion of a bottom surface (115BS) in the interior space.
    Type: Application
    Filed: August 1, 2002
    Publication date: August 21, 2003
    Applicant: MITSUBISHI DENKI KABUSHIKI
    Inventors: Masayoshi Hirao, Katsumi Satou, Shigeo Tooi
  • Publication number: 20030075728
    Abstract: The present invention has a purpose to provide a Schottky diode allowing obtaining a predetermined reverse-direction breakdown voltage even if a surface state in the vicinity of a Schottky junction interface changes due to the welding of the bonding wire. The semiconductor device having a Schottky junction includes a semiconductor substrate of the first conductivity type. A well region of the second conductivity type is formed in the top surface of the semiconductor substrate. A Schottky electrode is formed on the top surface of the semiconductor substrate and has a Schottky junction with the semiconductor substrate. A connecting conductive member is electrically connected on the Schottky electrode. And, the connecting conductive member is selectively connected with the Schottky electrode above the well region.
    Type: Application
    Filed: April 22, 2002
    Publication date: April 24, 2003
    Applicant: MITSUBISHI DENKI KABUSHIKI KAISHA
    Inventors: Shigeo Tooi, Katsumi Satoh