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:
Jan. 12, 1993
Filed:
Dec. 22, 1989
Applicant:
Inventors:
Wayne I Kinney, Albuquerque, NM (US);
John P Niemi, Albuquerque, NM (US);
Jonathan E Macro, Albuquerque, NM (US);
David Back, Son, NL;
Assignee:
North American Philips Corp., Signetics Division, Sunnyvale, CA (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ; H01L / ;
U.S. Cl.
CPC ...
437 78 ; 437 34 ; 437 79 ;
Abstract
A method of forming isolation trenches in CMOS integrated circuits is disclosed. The trench side walls are covered by a thin oxide layer, and the trenches are filled with a highly doped polysilicon. The doped polysilicon has a high work function which prevents oxide charges from inverting the trench side walls and thereby turns off the parasitic transistors at these side walls to reduce latchup.