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. 18, 1990
Filed:
Sep. 21, 1989
Applicant:
Inventors:
Assignee:
STC PLC, London, GB;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
437 20 ; 437 26 ; 437 69 ; 437940 ;
Abstract
Isolation trenches are formed in a semiconductor, e.g. silicon, substrate by selectively doping the substrate and preferentially oxidizing the doped material. Typically the dopant is arsenic or phosphorus and preferably the substrate is doped to a level of at least 5.times.10.sup.19 cm.sup.-3.