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:
Nov. 12, 1991
Filed:
Dec. 18, 1990
Applicant:
Inventor:
Douglas P Verret, Sugarland, TX (US);
Assignee:
Texas Instruments Incorporated, Dallas, TX (US);
Primary Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
357 49 ;
Abstract
An isolation structure for bipolar and CMOS circuits formed during the same processing steps to optimize the integration of bipolar and CMOS circuits. A deep trench (46) is formed in a semiconductor circuit for providing deep isolation for bipolar circuits. A shallow recess (56) is then formed simultaneous with a stepped sidewall structure of the deep trench. The recess (56) and the trench (46) are covered by an insulating oxide (60). and thereafter filled with an undoped polysilicon (62) to form the different isolating structures for the different types of circuits.