The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 19, 1989
Filed:
Feb. 13, 1989
Deems R Hollingsworth, Missouri City, TX (US);
Steve Thompson, Richmond, TX (US);
Harry F Pang, Houston, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A method of making a bipolar transistor in an LSI or VLSI process which includes forming a buried DUF collector of a first conductivity type, growing an epitaxial layer of a first conductivity type over said DUF collector and forming isolation means around a transistor region. The transistor region includes a trench which at least partially encloses the transistor region and extends through the DUF collector. Emitter and base regions of the first and second conductivity types, respectively, are formed in the epitaxial layer. A collector contact region of the first conductivity is formed in the epitaxial layer and extends down to the buried DUF collector.