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:
Dec. 08, 1987
Filed:
Mar. 03, 1986
Michael D Lammert, Manhattan Beach, CA (US);
TRW Inc., Redondo Beach, CA (US);
Abstract
A low collector parasitic resistance in bipolar transistors may be achieved without the use of an epitaxial layer or a high energy implant. Essentially, the invention employs the use of trenches in an N.sup.- layer overlying a P.sup.- substrate to surround the transistor, forming an N.sup.+ region in the walls defining the trench and below the surface, extending the trench into the P.sup.- substrate, implanting the bottom of the trench with a P-type dopant and refilling the trench with insulating material. The process of the invention permits fabrication of complex bipolar integrated circuits having a very high performance, and is particularly adaptable to very small geometry devices of 1 .mu.m and lower.