Patents by Inventor Ryohei GEJO

Ryohei GEJO 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: 20150091055
    Abstract: A semiconductor device includes a first region of a first conductivity type, a collector electrode electrically connected to a first side of the first region, first and second gate electrodes and first and second conductor electrodes, each of the gate and conductor electrodes extending into the first region from a second side thereof that is opposite to the first side, an emitter electrode electrically connected to the conductor electrodes, and a second region of the first conductivity type, that is adjacent to the gate electrodes, electrically connected to the emitter electrode, and spaced from the first and second conductor electrodes.
    Type: Application
    Filed: February 28, 2014
    Publication date: April 2, 2015
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Ryohei GEJO, Kazutoshi NAKAMURA, Tsuneo OGURA, Tomoko MATSUDAI
  • Publication number: 20140061875
    Abstract: According one embodiment, a semiconductor device includes: a first electrode; a second electrode; a first semiconductor layer provided between the first electrode and the second electrode and being in contact with the first electrode; a second semiconductor layer including a first part and a second part, and the second part being contact with the first electrode, and the second semiconductor layer having an effective impurity concentration lower than an effective impurity concentration in the first semiconductor layer; a third semiconductor layer provided between the second semiconductor layer and the second electrode, and having an effective impurity concentration lower than an effective impurity concentration in the second semiconductor layer; and a fourth semiconductor layer provided between the third semiconductor layer and the second electrode, and being in contact with the second electrode.
    Type: Application
    Filed: August 29, 2013
    Publication date: March 6, 2014
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Tsuneo OGURA, Tomoko MATSUDAI, Yuuichi OSHINO, Yoshiko IKEDA, Kazutoshi NAKAMURA, Ryohei GEJO
  • Publication number: 20130248925
    Abstract: According to an embodiment, a power semiconductor device includes a semiconductor substrate, a base layer, a device portion, a guard ring, and an insulator. The semiconductor substrate includes a drift layer with a first conductive type. The base layer has a second conductive type and is selectively formed in a surface of the drift layer. The device portion is formed on the surfaces of the base layer and the drift layer. The guard ring has a second conductive type and is disposed in plural and is selectively formed in the surface of the drift layer around the device portion. The insulator is buried in at least one of the guard rings.
    Type: Application
    Filed: February 28, 2013
    Publication date: September 26, 2013
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Ryohei GEJO
  • Publication number: 20130037851
    Abstract: A semiconductor device including a base semiconductor layer of a first conductivity type, a cell portion including a diffusion region of a second conductivity type formed on a surface of the base semiconductor layer, a plurality of guard ring semiconductor layers of the second conductivity type formed on the surface of the base semiconductor layer, each guard ring semiconductor layer being formed to surround the cell portion, a plurality of first RESURF semiconductor layers of the first conductivity type provided on the surface of the base semiconductor layer inside the plurality of guard ring semiconductor layers and having a higher concentration than the base semiconductor layer and a second RESURF semiconductor layer of the first conductivity type provided on the surface of the base semiconductor layer between the outermost guard ring semiconductor layer and the EQPR semiconductor layer.
    Type: Application
    Filed: March 14, 2012
    Publication date: February 14, 2013
    Applicant: Kabushiki Kaisha Toshiba
    Inventor: Ryohei GEJO
  • Publication number: 20120241813
    Abstract: A power semiconductor device includes a first semiconductor layer of a first conduction type, a second semiconductor layer of the first conduction type, a third semiconductor layer of a second conduction type, a fourth semiconductor layer of the first conduction type, a gate insulating film, a gate electrode, an interlayer insulating film, a fifth semiconductor layer of the second conduction type, a sixth semiconductor layer of the second conduction type, an insulative current narrowing body, a first electrode, and a second electrode. The sixth semiconductor layer of the second conduction type contains a second conduction type impurity in a concentration higher than a second conduction type impurity concentration of the fifth semiconductor layer. The insulative current narrowing body is provided in the fifth semiconductor layer. The insulative current narrowing body has a surface parallel to the surface of the fifth semiconductor layer and a space provided in the surface.
    Type: Application
    Filed: September 21, 2011
    Publication date: September 27, 2012
    Applicant: Kabushiki Kaisha Toshiba
    Inventor: Ryohei GEJO