Patents by Inventor Michiko Tokuyama

Michiko Tokuyama 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 of manufacturing a semiconductor device readily capable of removing contaminants from a silicon substrate
    Patent number: 5444001
    Abstract: For removing contaminants (32) from a silicon substrate (31) having a principal surface (31a), a polycrystalline silicon film (34) is formed on an oxidation film (33) which is formed by oxidizing the principal surface. Selective oxidation is used. As a result, the contaminants are mainly concentrated around an interface between the oxidation and the polycrystalline silicon films. Thereafter, the oxidation and the polycrystalline silicon films are deleted from the silicon substrate. Therefore, the contaminants are eliminated from the silicon substrate together with the oxidation and the polycrystalline silicon films.
    Type: Grant
    Filed: December 23, 1993
    Date of Patent: August 22, 1995
    Assignee: NEC Corporation
    Inventor: Michiko Tokuyama