Patents by Inventor Syunji Horikawa

Syunji Horikawa 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).

  • N-type group III nitride semiconductor layered structure
    Patent number: 7855386
    Abstract: An object of the present invention is to provide a low-resistance n-type Group III nitride semiconductor layered structure having excellent flatness and few pits. The inventive n-type group III nitride semiconductor layered structure comprises a substrate and, stacked on the substrate, an n-type impurity concentration periodic variation layer comprising an n-type impurity atom higher concentration layer and an n-type impurity atom lower concentration layer, said lower concentration layer being stacked on said higher concentration layer.
    Type: Grant
    Filed: April 27, 2005
    Date of Patent: December 21, 2010
    Assignee: Showa Denko K.K.
    Inventors: Akira Bandoh, Hiromitsu Sakai, Masato Kobayakawa, Mineo Okuyama, Hideki Tomozawa, Hisayuki Miki, Joseph Gaze, Syunji Horikawa, Tetsuo Sakurai
  • Group III nitride semiconductor light emitting device
    Patent number: 7456445
    Abstract: A Group III nitride semiconductor light emitting device having a light emitting layer (6) bonded to a crystal layer composed of an n-type or p-type Group III nitride semiconductor, the Group III nitride semiconductor light emitting device being characterized by comprising an n-type Group III nitride semiconductor layer (4) having germanium (Ge) added thereto and having a resistivity of 1×10?1 to 1×10?3 ?cm. The invention provides a Ge-doped n-type Group III nitride semiconductor layer with low resistance and excellent flatness, in order to obtain a Group III nitride semiconductor light emitting device exhibiting low forward voltage and excellent light emitting efficiency.
    Type: Grant
    Filed: May 20, 2005
    Date of Patent: November 25, 2008
    Assignee: Showa Denko K.K.
    Inventors: Hitoshi Takeda, Syunji Horikawa
  • N-Type Group III Nitride Semiconductor Layered Structure
    Publication number: 20080230800
    Abstract: An object of the present invention is to provide a low-resistance n-type Group III nitride semiconductor layered structure having excellent flatness and few pits. The inventive n-type group III nitride semiconductor layered structure comprises a substrate and, stacked on the substrate, an n-type impurity concentration periodic variation layer comprising an n-type impurity atom higher concentration layer and an n-type impurity atom lower concentration layer, said lower concentration layer being stacked on said higher concentration layer.
    Type: Application
    Filed: April 27, 2005
    Publication date: September 25, 2008
    Inventors: Akira Bandoh, Hiromitsu Sakai, Masato Kobayakawa, Mineo Okuyama, Hideki Tomozawa, Hisayuki Miki, Joseph Gaze, Syunji Horikawa, Tetsuo Sakurai
  • Group III Nitride Semiconductor Light Emitting Device
    Publication number: 20070228407
    Abstract: A Group III nitride semiconductor light emitting device having a light emitting layer (6) bonded to a crystal layer composed of an n-type or p-type Group III nitride semiconductor, the Group III nitride semiconductor light emitting device being characterized by comprising an n-type Group III nitride semiconductor layer (4) having germanium (Ge) added thereto and having a resistivity of 1×10?1 to 1×10?3 ?cm. The invention provides a Ge-doped n-type Group III nitride semiconductor layer with low resistance and excellent flatness, in order to obtain a Group III nitride semiconductor light emitting device exhibiting low forward voltage and excellent light emitting efficiency.
    Type: Application
    Filed: May 20, 2005
    Publication date: October 4, 2007
    Inventors: Hitoshi Takeda, Syunji Horikawa