Patents by Inventor David K. Hartman

David K. Hartman 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).

  • Open tube aluminum oxide disc diffusion
    Patent number: 4239560
    Abstract: A p-type region is formed in a semiconductor body by diffusion of aluminum from an aluminum oxide source in an open tube process. Both ceramic aluminum oxide and sapphire sources are described and an inert atmosphere of argon and hydrogen provides stable results. An alternative embodiment provides both the deep diffusion characteristics of aluminum with the high surface concentration of boron by using a boron nitride wafer carrier.
    Type: Grant
    Filed: May 21, 1979
    Date of Patent: December 16, 1980
    Assignee: General Electric Company
    Inventors: Mike F. Chang, David K. Hartman, Richard W. Kennedy, Alfred Roesch, Henri B. Assalit
  • Guard ring for TGZM processing
    Patent number: 4233934
    Abstract: A guard ring for processing a wafer of semiconductor material by thermal gradient zone melting has a beveled internal wall surface for supporting the wafer therein. The thickness of the guard ring is about twice the thickness of the wafer.
    Type: Grant
    Filed: December 7, 1978
    Date of Patent: November 18, 1980
    Assignee: General Electric Company
    Inventors: Thomas R. Anthony, Harvey E. Cline, David K. Hartman, Mike F. Chang
  • Semiconductor device and method of manufacture therefor
    Patent number: 3943621
    Abstract: A semiconductor device and method of manufacture therefor includes the establishment of at least one PN junction in a semiconductor chip through conventional techniques. Electrical contacts are formed. The entire semiconductor device is coated with a passivant coating having a first layer of low temperature silicon dioxide and a second layer of glass, the second layer of glass being applied in two steps.
    Type: Grant
    Filed: March 10, 1975
    Date of Patent: March 16, 1976
    Assignee: General Electric Company
    Inventor: David K. Hartman