Patents by Inventor Katsunori Koarai

Katsunori Koarai 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 wafer, and method of manufacturing the same
    Patent number: 5863659
    Abstract: A silicon wafer has a polycrystalline silicon film formed on one main surface. The polycrystalline silicon film has a multilayer structure composed of X layers (X is an integer equal to or greater than two) containing <220> oriented components in different proportions. The proportion of the <220> oriented component in the first polycrystalline silicon layer in contact with the silicon wafer is larger than the respective proportions of the <220> oriented components in the second to X-th polycrystalline silicon layers superposed on the first polycrystalline silicon layer. It becomes possible to provide a silicon wafer whose polycrystalline silicon film possesses high gettering capability and in which stress acting on the silicon wafer is decreased.
    Type: Grant
    Filed: March 24, 1997
    Date of Patent: January 26, 1999
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Norihiro Kobayashi, Katsunori Koarai