Patents by Inventor Sumitaka Itoh

Sumitaka Itoh 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).

  • Method of producing periodic table group 13 metal nitride semiconductor crystal and periodic table group 13 metal nitride semiconductor crystal produced by this production method
    Patent number: 9899568
    Abstract: For a Periodic Table Group 13 metal nitride semiconductor crystal obtained by epitaxial growth on the main surface of a base substrate that has a nonpolar plane and/or a semipolar plane as its main surface, an object of the present invention is to provide a high-quality semiconductor crystal that has a low absorption coefficient, is favorable for a device, and is controlled dopant concentration in the crystal, and to provide a production method that can produce the semiconductor crystal. A high-quality Periodic Table Group 13 metal nitride semiconductor crystal that has a precisely controlled dopant concentration within the crystal and a low absorption coefficient and that is thus favorable for a device, can be provided by inhibiting oxygen doping caused by impurity oxygen and having the Si concentration higher than the O concentration.
    Type: Grant
    Filed: April 21, 2014
    Date of Patent: February 20, 2018
    Assignee: Mistubishi Chemical Corporation
    Inventors: Yuya Saito, Sumitaka Itoh, Shigeru Terada, Hiromitsu Kimura
  • METHOD OF PRODUCING PERIODIC TABLE GROUP 13 METAL NITRIDE SEMICONDUCTOR CRYSTAL AND PERIODIC TABLE GROUP 13 METAL NITRIDE SEMICONDUCTOR CRYSTAL PRODUCED BY THIS PRODUCTION METHOD
    Publication number: 20140294713
    Abstract: For a Periodic Table Group 13 metal nitride semiconductor crystal obtained by epitaxial growth on the main surface of a base substrate that has a nonpolar plane and/or a semipolar plane as its main surface, an object of the present invention is to provide a high-quality semiconductor crystal that has a low absorption coefficient, is favorable for a device, and is controlled dopant concentration in the crystal, and to provide a production method that can produce the semiconductor crystal. A high-quality Periodic Table Group 13 metal nitride semiconductor crystal that has a precisely controlled dopant concentration within the crystal and a low absorption coefficient and that is thus favorable for a device, can be provided by inhibiting oxygen doping caused by impurity oxygen and having the Si concentration higher than the O concentration.
    Type: Application
    Filed: April 21, 2014
    Publication date: October 2, 2014
    Applicant: MITSUBISHI CHEMICAL CORPORATION
    Inventors: Yuya SAITO, Sumitaka Itoh, Shigeru Terada, Hiromitsu Kimura