Patents by Inventor Yasunori Hirata

Yasunori Hirata 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: 7947577
    Abstract: A method of producing a group III nitride such as aluminum nitride, comprising the step of reacting a group III halide gas such as aluminum trichloride gas with a nitrogen source gas such as ammonia gas in a growth chamber to grow a group III nitride on a substrate held in the growth chamber, wherein the method further comprises premixing together the group III halide gas and the nitrogen source gas to obtain a mixed gas and then introducing the mixed gas into the growth chamber without forming a deposit in the mixed gas substantially to be reacted each other. For the growth of a group III nitride such as an aluminum-based group III nitride by HVPE, there are provided a method of producing the group III nitride having as high quality as that obtained by the method of the prior art at a high yield and an apparatus used in the method.
    Type: Grant
    Filed: August 3, 2007
    Date of Patent: May 24, 2011
    Assignee: Tokuyama Corporation
    Inventors: Toru Nagashima, Kazuya Takada, Hiroyuki Yanagi, Manabu Harada, Yasunori Hirata, Keisuke Kondo
  • Publication number: 20100029065
    Abstract: A method of producing a group III nitride such as aluminum nitride, comprising the step of reacting a group III halide gas such as aluminum trichloride gas with a nitrogen source gas such as ammonia gas in a growth chamber to grow a group III nitride on a substrate held in the growth chamber, wherein the method further comprises premixing together the group III halide gas and the nitrogen source gas to obtain a mixed gas and then introducing the mixed gas into the growth chamber without forming a deposit in the mixed gas substantially to be reacted each other. For the growth of a group III nitride such as an aluminum-based group III nitride by HVPE, there are provided a method of producing the group III nitride having as high quality as that obtained by the method of the prior art at a high yield and an apparatus used in the method.
    Type: Application
    Filed: August 3, 2007
    Publication date: February 4, 2010
    Inventors: Toru Nagashima, Kazuya Takada, Hiroyuki Yanagi, Manabu Harada, Yasunori Hirata, Keisuke Kondo
  • Patent number: 5929280
    Abstract: There is provided a simple method of producing in a good yield a tetraalkylammonium hydroxide aqueous solution in which the content of metal ions such as alkali metal ions is reduced to an extremely low level.High-purity trialkylamine and high-purity alkyl chloride are reacted with each other in ultrapure water to obtain an extremely high-purity tetraalkylammonium chloride aqueous solution substantially free from metal ions such as alkali metal ions, and then, the tetraalkylammonium chloride aqueous solution is subjected to electrolysis-dialysis in a solution state without drying it into a solid to produce a tetraalkylammonium hydroxide aqueous solution. Thereby, an extremely high-purity tetraalkylammonium hydroxide aqueous solution with little reduction in purity is obtained in a high yield.
    Type: Grant
    Filed: March 23, 1998
    Date of Patent: July 27, 1999
    Assignee: Tokuyama Corporation
    Inventors: Tooru Nonaka, Yasunori Hirata, Masafumi Shibuya