Patents by Inventor Katsuhisa Ohkawa

Katsuhisa Ohkawa 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).

  • Polishing process monitoring method and apparatus, its endpoint detection method, and polishing machine using same
    Patent number: 6425801
    Abstract: A polishing process monitoring apparatus of a semiconductor wafer is provided, which is capable of monitoring correctly the process independent of various factors affecting optical measurement, such as the configuration, material, and size of a layered structure on the wafer, and the geometric shapes of patterns and their arrangement for respective semiconductor chips.
    Type: Grant
    Filed: June 1, 1999
    Date of Patent: July 30, 2002
    Assignee: NEC Corporation
    Inventors: Akira Takeishi, Hideo Mitsuhashi, Katsuhisa Ohkawa, Yoshihiro Hayashi, Takahiro Onodera