Patents by Inventor Wilhelmina C. E. Snels

Wilhelmina C. E. Snels 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 of manufacturing a semiconductor device, in which a silicon wafer is provided at its surface with field oxide regions
    Patent number: 4906595
    Abstract: A method of manufacturing a semiconductor device, in which a surface (1) of a silicon wafer (2) is locally provided with an oxidation mask (3), whereupon the wafer is subjected to an oxidation treatment by heating it in an oxidizing gas mixture. According to the invention, the wafer is heated during the treatment in the oxidizing gas mixture to a temperature of 950.degree. to 1050.degree. C. Water is then added to the oxidizing gas mixture. The quantity of added water is initially less than 30% by volume and later larger. Thus, in a comparatively short time a comparatively thick layer of oxide can be formed without defects being formed in silicon lying under the oxide.
    Type: Grant
    Filed: July 21, 1989
    Date of Patent: March 6, 1990
    Assignee: U.S. Philips Corporation
    Inventors: Paulus A. van der Plas, Wilhelmina C. E. Snels