Patents by Inventor Frederic N. Schwettmann

Frederic N. Schwettmann 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: 4971851
    Abstract: A layered structure for use in an X-ray membrane (pellicle) mask or a vacuum window is provided in which an intermediate amorphous layer such as silicon dioxide is grown on a silicon substrate which provides a stress relief medium and surface properties which enhance and improve subsequent process layers by breaking the epitaxial nature of these later deposited layers. Upon subsequent deposition of an inorganic overcoat, such as SiC, on the intermediate amorphous layer, the overcoat produces a nearly defect-free layer with a substantially reduced stress of suitable quality for X-ray lithography mask fabrication. Furthermore, additional alternating layers of a silicon carbide film and an intermediate inorganic layer, such as silicon nitride, can be deposited to obtain an even smoother silicon carbide surface and stronger structure.
    Type: Grant
    Filed: November 18, 1985
    Date of Patent: November 20, 1990
    Assignee: Hewlett-Packard Company
    Inventors: Armand P. Neukermans, Kuo L. Chiang, Frederic N. Schwettmann, Donald R. Bradbury
  • Patent number: 4608326
    Abstract: A layered structure for use in an X-ray membrane (pellicle) mask or a vacuum window is provided in which an intermediate amorphous layer such as silicon dioxide is grown on a silicon substrate which provides a stress relief medium and surface properties which enhance and improve subsequent process layers by breaking the epitaxial nature of these later deposited layers. Upon subsequent deposition of an inorganic overcoat, such as SiC, on the intermediate amorphous layer, the overcoat produces a nearly defect-free layer with a substantially reduced stress of suitable quality for X-ray lithography mask fabrication. Furthermore, additional alternating layers of a silicon carbide film and an intermediate inorganic layer, such as silicon nitride, can be deposited to obtain an even smoother silicon carbide surface and stronger structure.
    Type: Grant
    Filed: December 4, 1985
    Date of Patent: August 26, 1986
    Assignee: Hewlett-Packard Company
    Inventors: Armand P. Neukermans, Kuo L. Chiang, Frederic N. Schwettmann, Donald R. Bradbury