Patents by Inventor W. R. Trutna

W. R. Trutna 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).

  • Patent number: 4681430
    Abstract: An improved method for automatically focusing an integrated circuit manufacturing projection step and repeat photolithography printer employing an optical signal to focus the printer is disclosed. The automatic focusing is achieved by reflecting an optical signal off a photoresist layer on the surface of a wafer and converting the reflected optical signal into an electronic signal employed to focus the printer. According to the preferred embodiment of the present invention, a dye which absorbs light at the wavelength the optical signal is added to the photoresist layer to improve the quality of the reflected optical signal thereby considerably reducing or eliminating focusing errors.
    Type: Grant
    Filed: August 27, 1986
    Date of Patent: July 21, 1987
    Assignee: Hewlett-Packard Company
    Inventors: Atul Goel, Keith G. Bartlett, W. R. Trutna