Patents by Inventor Charles Curtis Burkhart

Charles Curtis Burkhart 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).

  • Oscillating crucible for stabilization of Czochralski (CZ) silicon melt
    Patent number: 5902394
    Abstract: A method is provided for stabilizing Czochralski (CZ) silicon melt by controlled oscillation of the crucible rotation during the stabilization period of the silicon melt to reduce the gas bubbles and unmelted polysilicon particles contained therein and thereby increase the yield and productivity of CZ silicon crystal production. The crucible rotation is controlled to follow an Oscillating Crucible Rotation (OCR) pattern or a saw tooth rotation pattern, which include rapid oscillations between a high rate of rotation and a low rate of rotation of the crucible during a period prior to the growth of the CZ crystal ingot.
    Type: Grant
    Filed: March 31, 1997
    Date of Patent: May 11, 1999
    Assignee: SEH America, Inc.
    Inventors: Charles Curtis Burkhart, Bruce Laurence Colburn