Patents by Inventor David W. T. Yau

David W. T. Yau 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).

  • Thermo-mechanical overlay signature tuning for Perkin-Elmer mask aligner
    Patent number: 4540251
    Abstract: Thermoelectric heat pumps are individually located at multiple flexures functioning to support a primary mirror which mirror reflects light from an aluminum mask onto a semiconductor wafer. The heat pumps are selectively energized to apply thermal stresses by heat or cold application at the flexures into the primary mirror suspension to compensate for distortions in the image transfer between the mask and the semiconductor wafer.
    Type: Grant
    Filed: December 1, 1983
    Date of Patent: September 10, 1985
    Assignee: International Business Machines Corporation
    Inventors: David W. T. Yau, Robert A. Modavis