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. 26, 1989
Filed:
Oct. 09, 1987
Applicant:
Inventors:
William G Easter, Reading, PA (US);
Daniel D Leffel, Earl Township, Berks County, PA (US);
Assignee:
American Telephone and Telegraph Company, AT&T-Technologies, Inc., Berkeley Heights, NJ (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ; H01L / ;
U.S. Cl.
CPC ...
437 78 ; 437 90 ; 437 62 ; 437 67 ; 148D / ;
Abstract
A method has been developed for altering the resistivity of selected regions (tubs) in a dielectrically isolated (DI) wafer. Subsequent to the formation of the conventional tub structure, the wafer is patterned and etched to expose selected tubs. These tubs are then etched and selectively implanted and an epitaxial layer of a new resistivity value is grown in the empty tube regions. The resistivity of the epitaxial material may be chosen to alter the conductivity of the selected tub regions.