Patents by Inventor Michiharu Tamura

Michiharu Tamura 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 for production of dislocation-free silicon single crystal
    Patent number: 6080237
    Abstract: This invention is directed to a method for the production of a dislocation-free silicon single crystal by the Czochralski method. This method attains growth of the main body part of the dislocation-free silicon single crystal by immersing a seed crystal in a melt of silicon and then pulling the seed crystal without recourse to the necking. The seed crystal thus used is a dislocation-free silicon single crystal. The horizontal maximum length of the part of the seed crystal being immersed in the melt at the time of completing the immersion of the seed crystal in the melt is not less than 5 mm. The immersing rate of the seed crystal in the melt is not more than 2.8 mm/min and the part of the seed crystal to be immersed in the melt is a crystal as grown.
    Type: Grant
    Filed: June 8, 1998
    Date of Patent: June 27, 2000
    Assignees: Nippon Steel Corporation, NSC Electron Corporation
    Inventors: Toshio Iwasaki, Shin-ichi Fujimoto, Hiroshi Isomura, Takayoshi Ishida, Michiharu Tamura, Atsushi Ikari