Patents by Inventor Syunji Nonaka

Syunji Nonaka 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).

  • Silicon single crystal producing method, annealed wafer, and method of producing annealed wafer
    Patent number: 7875116
    Abstract: A method in which SSDs are reliably reduced while reducing void defects other than the SSDs on a wafer surface, which is essential for an annealed wafer, and ensuring that BMDs serving as gettering source in a bulk are generated, in order to stabilize the quality of the annealed wafer. Considering that annealing a silicon wafer leads to an increase of density (quantity) of deposits associated with oxygen and nitrogen and forming a core of the SSDs, SSDs are decreased by reducing the density (quantity) of the deposits associated with oxygen and nitrogen by controlling three parameters of oxygen concentration, nitrogen concentration and cooling concentration during the process of pulling and growing the silicon single crystal 6 before annealing. Alternatively, SSD is reduced by polishing after annealing.
    Type: Grant
    Filed: February 14, 2006
    Date of Patent: January 25, 2011
    Assignee: Sumco Techxiv Corporation
    Inventors: Shinya Sadohara, Ryota Suewaka, Shiro Yoshino, Kozo Nakamura, Yutaka Shiraishi, Syunji Nonaka
  • Silicon Single Crystal Producing Method, Annealed Wafer, and Method of Producing Annealed Wafer
    Publication number: 20090061140
    Abstract: A method in which SSDs are reliably reduced while reducing void defects other than the SSDs on a wafer surface, which is essential for an annealed wafer, and ensuring that BMDs serving as gettering source in a bulk are generated, in order to stabilize the quality of the annealed wafer. Considering that annealing a silicon wafer leads to an increase of density (quantity) of deposits associated with oxygen and nitrogen and forming a core of the SSDs, SSDs are decreased by reducing the density (quantity) of the deposits associated with oxygen and nitrogen by controlling three parameters of oxygen concentration, nitrogen concentration and cooling concentration during the process of pulling and growing the silicon single crystal 6 before annealing. Alternatively, SSD is reduced by polishing after annealing.
    Type: Application
    Filed: February 14, 2006
    Publication date: March 5, 2009
    Applicant: SUMCO TECHXIV KABUSHIKI KAISHA
    Inventors: Shinya Sadohara, Ryota Suewaka, Shiro Yoshino, Kozo Nakamura, Yutaka Shiraishi, Syunji Nonaka