Patents by Inventor Thomas E. Ham

Thomas E. Ham 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).

  • Bipolar fabrication method
    Patent number: 5244821
    Abstract: A method for forming a bipolar transistor is disclosed. An optional thin screen oxide (.apprxeq.150 .ANG.) may be formed upon a substrate over an already-defined collector region. A BF.sub.2 or other implantation is performed through the screen oxide to create the base. The screen oxide is removed and replaced with a patterned high pressure oxide so that the emitter may be defined. The resulting device has a more controllable Gummel number and breakdown voltage.
    Type: Grant
    Filed: June 7, 1991
    Date of Patent: September 14, 1993
    Assignee: AT&T Bell Laboratories
    Inventors: Thomas E. Ham, John W. Osenbach, Morgan J. Thoma, Susan C. Vitkavage