Patents by Inventor Koukiti Tanaka

Koukiti Tanaka 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 forming mask alignment marks
    Patent number: 5128283
    Abstract: A method of producing a semiconductor device including processes of forming an optically transparent film on a semiconductor substrate having an alignment mark, and thereafter forming an optically opaque film, includes the step of selectively etching said transparent film to remove at least a part thereof disposed above said alignment mark, and thereafter forming said optically opaque film on said semiconductor substrate.
    Type: Grant
    Filed: June 8, 1989
    Date of Patent: July 7, 1992
    Assignee: Nec Corporation
    Inventor: Koukiti Tanaka