Patents by Inventor Nobuaki Shigematsu

Nobuaki Shigematsu 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 nitride film formation method
    Patent number: 6355582
    Abstract: In a silicon nitride film formation method, a substrate to be subjected to film formation is heated, and silicon tetrachloride and ammonia gases are supplied to the substrate heated to a predetermined temperature. The ratio of the partial pressure of the silicon tetrachloride gas to that of the ammonia gas is set to not less than 0.5.
    Type: Grant
    Filed: September 14, 2000
    Date of Patent: March 12, 2002
    Assignee: Tokyo Electron Limited
    Inventors: Keizo Hosoda, Nobuaki Shigematsu, Yusuke Muraki, Atsushi Sato
  • Method for forming doped polysilicon films
    Patent number: 5783257
    Abstract: A number of wafers are loaded into a reaction vessel on a wafer boat; monosilane gas, phosphine gas and N.sub.2 O gas are supplied to form amorphous silicon film doped with, e.g., phosphorus; and then the wafers are annealed in, e.g., a different reaction tube to polycrystallize the amorphous silicon film. Os (Oxygen) generated by decomposition of N.sub.2 O are taken into the film. The Os become nuclei of the silicon crystals, and the crystals become fine and have size uniformity. As a result, high uniformity of resistance values of micronized devices of the polysilicon film can be obtained. Resistance values of the polysilicon film can be easily controlled by addition of oxygen. As a result, high uniformity of resistance values of micronized devices of the polysilicon film can be obtained.
    Type: Grant
    Filed: May 29, 1997
    Date of Patent: July 21, 1998
    Assignees: Tokyo Electron Limited, Electron Tohoku Limited, NEC Corporation
    Inventors: Seiichi Shishiguchi, Kazuhide Hasebe, Nobuaki Shigematsu