Patents by Inventor Hozumi Yasuda

Hozumi Yasuda 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 and apparatus for polishing workpiece
    Patent number: 5651724
    Abstract: A predetermined amount of liquid such as water is supplied to a backside surface of a workpiece such as a semiconductor wafer. Such liquid is a workpiece retaining liquid and is attached to a concave workpiece holding surface of a top ring. The workpiece is positioned between a turntable and the top ring and is polished by an abrasive cloth on the turntable while the workpiece is being pressed against the turntable by the top ring. While polishing, the workpiece is deformed toward the concave workpiece holding surface of the top ring, and a curvature of the deformed workpiece is controlled by the amount of liquid between the workpiece holding surface and the backside surface of the workpiece.
    Type: Grant
    Filed: September 7, 1995
    Date of Patent: July 29, 1997
    Assignee: Ebara Corporation
    Inventors: Norio Kimura, Takayoshi Kawamoto, You Ishii, Katsuyuki Aoki, Kunio Tateishi, Hozumi Yasuda, Keisuke Namiki