Patents by Inventor Kouji Hishimoto

Kouji Hishimoto 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).

  • Exposure mask, method of manufacturing the same, and exposure method using the same
    Patent number: 5358808
    Abstract: An exposure mask for lithography, a method of manufacturing the same, and an exposure method using the same are disclosed. A light-transmitting opening of the exposure mask has a main light-transmitting region located in the middle of the opening and having a first optical path length, and phase shift regions adjacent to a light-shielding layer and having a second optical path length, different from the first optical path length. Light transmitted through each phase shift region interferes with light transmitted through the main light-transmitting region at the edges of the light-transmitting opening, thus enabling a sharp photo-intensity distribution of total transmitted light to be obtained. As a result, the resolution of the exposure mask is improved.
    Type: Grant
    Filed: July 21, 1993
    Date of Patent: October 25, 1994
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Akihiro Nitayama, Makoto Nakase, Kouji Hishimoto, Hirotsugu Wada