Patents by Inventor Norihiko Mizutani

Norihiko Mizutani 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).

  • Inspection method and device of wafer surface
    Patent number: 5903342
    Abstract: A wafer surface inspection method and device including a low angle light receiving system having an elevation angle less than 30.degree. with reference to the wafer surface, and a high angle light receiving system having an elevation angle equal to or larger than 30.degree., scans the wafer with a laser beam, receives scattered light to perform extraneous substance detection in response to the scanning, and detects wafer defects only by the high angle light receiving system, and sticking extraneous substances by either the low angle receiving system or by both the low angle light receiving system and the high angle light receiving system.
    Type: Grant
    Filed: April 8, 1996
    Date of Patent: May 11, 1999
    Assignee: Hitachi Electronics Engineering, Co., Ltd.
    Inventors: Yasuo Yatsugake, Takashi Okawa, Norihiko Mizutani, Shigeharu Iizuka