Patents by Inventor Makiko Kiyomi

Makiko Kiyomi 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).

  • Process for producing nitride crystal, nitride crystal and apparatus for producing same
    Patent number: 9192910
    Abstract: To grow a highly pure nitride crystal having a low oxygen concentration efficiently by an ammonothermal method. A process for producing a nitride crystal, which comprises bringing a reactant gas reactive with ammonia to form a mineralizer, and ammonia into contact with each other to prepare a mineralizer in a reactor or in a closed circuit connected to a reactor; and growing a nitride crystal by an ammonothermal method in the presence of the ammonia and the mineralizer.
    Type: Grant
    Filed: January 7, 2010
    Date of Patent: November 24, 2015
    Assignees: Mitsubishi Chemical Corporation, Tohoku University
    Inventors: Yutaka Mikawa, Makiko Kiyomi, Yuji Kagamitani, Toru Ishiguro
  • Production method, production vessel and member for nitride crystal
    Patent number: 8609059
    Abstract: To provide a production method for a nitride crystal, where a nitride crystal can be prevented from precipitating in a portion other than on a seed crystal and the production efficiency of a gallium nitride single crystal grown on the seed crystal can be enhanced. In a method for producing a nitride crystal by an ammonothermal method in a vessel containing a mineralizer-containing solution, out of the surfaces of said vessel and a member provided in said vessel, at least a part of the portion coming into contact with said solution is constituted by a metal or alloy containing one or more atoms selected from the group consisting of tantalum (Ta), tungsten (W) and titanium (Ti), and has a surface roughness (Ra) of less than 1.80 ?m.
    Type: Grant
    Filed: May 29, 2012
    Date of Patent: December 17, 2013
    Assignees: Mitsubishi Chemical Corporation, Tohoku University, The Japan Steel Works, Ltd.
    Inventors: Yutaka Mikawa, Makiko Kiyomi, Yuji Kagamitani, Toru Ishiguro, Yoshihiko Yamamura
  • PRODUCTION METHOD, PRODUCTION VESSEL AND MEMBER FOR NITRIDE CRYSTAL
    Publication number: 20120237431
    Abstract: To provide a production method for a nitride crystal, where a nitride crystal can be prevented from precipitating in a portion other than on a seed crystal and the production efficiency of a gallium nitride single crystal grown on the seed crystal can be enhanced. In a method for producing a nitride crystal by an ammonothermal method in a vessel containing a mineralizer-containing solution, out of the surfaces of said vessel and a member provided in said vessel, at least a part of the portion coming into contact with said solution is constituted by a metal or alloy containing one or more atoms selected from the group consisting of tantalum (Ta), tungsten (W) and titanium (Ti), and has a surface roughness (Ra) of less than 1.80 ?m.
    Type: Application
    Filed: May 29, 2012
    Publication date: September 20, 2012
    Applicants: MITSUBISHI CHEMICAL CORPORATION, THE JAPAN STEEL WORKS, LTD., TOHOKU UNIVERSITY
    Inventors: YUTAKA MIKAWA, MAKIKO KIYOMI, YUJI KAGAMITANI, TORU ISHIGURO, YOSHIHIKO YAMAMURA
  • PROCESS FOR PRODUCING NITRIDE CRYSTAL, NITRIDE CRYSTAL AND APPARATUS FOR PRODUCING SAME
    Publication number: 20110268645
    Abstract: To grow a highly pure nitride crystal having a low oxygen concentration efficiently by an ammonothermal method. A process for producing a nitride crystal, which comprises bringing a reactant gas reactive with ammonia to form a mineralizer, and ammonia into contact with each other to prepare a mineralizer in a reactor or in a closed circuit connected to a reactor; and growing a nitride crystal by an ammonothermal method in the presence of the ammonia and the mineralizer.
    Type: Application
    Filed: January 7, 2010
    Publication date: November 3, 2011
    Applicants: TOHOKU UNIVERSITY, MITSUBISHI CHEMICAL CORPORATION
    Inventors: Yutaka Mikawa, Makiko Kiyomi, Yuji Kagamitani, Toru Ishiguro