Patents by Inventor Raymond G. Seidensticker, deceased

Raymond G. Seidensticker, deceased 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: 5968261
    Abstract: An apparatus for growing single-polytype, single crystals of silicon carbide utilizing physical vapor transport as the crystal growth technique. The apparatus has a furnace which has a carbon crucible with walls that border and define a crucible cavity. A silicon carbide source material provided at a first location of the crucible cavity, and a monocrystalline silicon carbide seed is provided at a second location of the crucible cavity. A heat path is also provided in the furnace above the crucible cavity. The crucible has a stepped surface that extends into the crucible cavity. The stepped surface has a mounting portion upon which the seed crystal is mounted. The mounting portion of the stepped surface is bordered at one side by the crucible cavity and is bordered at an opposite side by the furnace heat path. The stepped surface also has a sidewall that is bordered at one side by and surrounds the furnace heat path.
    Type: Grant
    Filed: April 21, 1997
    Date of Patent: October 19, 1999
    Assignee: Northrop Grumman Corporation
    Inventors: Donovan L. Barrett, Raymond G. Seidensticker, deceased, Richard H. Hopkins
  • Patent number: 5746827
    Abstract: A method for producing crystals of silicon carbide in a furnace. The furnace has a crucible with a cavity in which the cavity has first and second spaced-apart regions. The crucible cavity of the furnace is capable of being heated, preferably by induction or resistance heating, with insulation placed around the crucible and crucible cavity. A source material of silicon carbide is provided at the first region of the crucible cavity, and a monocrystalline seed is placed at the second region of the crucible cavity. A first growth stage is then conducted in which the first region and the second region of the crucible cavity are heated to at least the sublimation temperature of silicon carbide under substantially isothermal conditions. Then, a second growth stage is conducted in which a temperature gradient is provided between the first and the second region of the crucible cavity, such that the seed in the second crucible region is kept at a temperature lower than a temperature of the first crucible region.
    Type: Grant
    Filed: December 27, 1995
    Date of Patent: May 5, 1998
    Assignee: Northrop Grumman Corporation
    Inventors: Donovan L. Barrett, Richard N. Thomas, Raymond G. Seidensticker, deceased, Richard H. Hopkins
  • Patent number: 5683507
    Abstract: An apparatus for growing single-polytype, single crystals of silicon carbide utilizing physical vapor transport as the crystal growth technique. The apparatus has a furnace which has a carbon crucible with walls that border and define a crucible cavity. A silicon carbide source material provided at a first location of the crucible cavity, and a monocrystalline silicon carbide seed is provided at a second location of the crucible cavity. A heat path is also provided in the furnace above the crucible cavity. The crucible has a stepped surface that extends into the crucible cavity. The stepped surface has a mounting portion upon which the seed crystal is mounted. The mounting portion of the stepped surface is bordered at one side by the crucible cavity and is bordered at an opposite side by the furnace heat path. The stepped surface also has a sidewall that is bordered at one side by and surrounds the furnace heat path.
    Type: Grant
    Filed: September 5, 1995
    Date of Patent: November 4, 1997
    Assignee: Northrop Grumman Corporation
    Inventors: Donovan L. Barrett, Raymond G. Seidensticker, deceased, Richard H. Hopkins