Patents by Inventor Geoffrey L. Ashcroft

Geoffrey L. Ashcroft 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).

  • Plasma etching
    Patent number: 4073669
    Abstract: Aluminum films on a semiconductor surface are etched in a carbon tetrachloride glow discharge. Typical etch rates are 2000-3000 A/min. The addition of 15% ammonia to the plasma prevents HCl formation when the etched material is exposed to air.This process provides a more easily controlled process for the manufacture of high density integrated circuits.
    Type: Grant
    Filed: April 29, 1976
    Date of Patent: February 14, 1978
    Assignee: ITT Industries, Incorporated
    Inventors: Rudolf A. H. Heinecke, Geoffrey L. Ashcroft