Patents by Inventor William C. Joyce

William C. Joyce 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 monitoring lithographic exposure
    Patent number: 5508803
    Abstract: A lithographic mask with an exposure monitor for imaging a gray scale feature. The exposure monitor has abutting regions of differing optical density disposed on the mask for imaging the gray scale feature by taking advantage of diffraction effects. After calibrating gray scale feature size to critical feature size, a gray scale feature may be imaged to monitor critical feature size due to exposure.
    Type: Grant
    Filed: December 20, 1994
    Date of Patent: April 16, 1996
    Assignee: International Business Machines Corporation
    Inventors: Michael S. Hibbs, William C. Joyce