Patents by Inventor James E. Griffiths

James E. Griffiths 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 for the optical monitoring of plasma discharge processing operations
    Patent number: 4312732
    Abstract: The endpoints of plasma discharge processing operations (e.g., plasma stripping of photoresists and plasma etching) are determined by monitoring the light produced in the space surrounding the object being processed. The optical monitor includes a wavelength selective device which is adjusted to transmit light from a selected excited species, which includes particles from the surface being processed. The surface includes a layer of one material overlaying a second material. If the selected excited species includes particles of the first material, then the endpoint of the removal operation occurs when the monitored intensity falls below a predetermined threshold level. When the selected excited species includes particles of the second material, then the endpoint occurs when the monitored intensity rises above a preselected threshold level.
    Type: Grant
    Filed: March 10, 1980
    Date of Patent: January 26, 1982
    Assignee: Bell Telephone Laboratories, Incorporated
    Inventors: Eugene O. Degenkolb, James E. Griffiths, Cyril J. Mogab