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:
Aug. 18, 1987
Filed:
May. 02, 1986
Jeffrey T Koze, Whitehall, PA (US);
American Telephone and Telegraph Company, AT&T Technologies, Inc., Berkeley Heights, NJ (US);
Abstract
Sealing the backside of a semiconductor wafer prevents evaporation of the dopant (typically boron) when an epitaxial layer is grown on the front (active) side, thereby preventing autodoping of the epitaxial layer with excess dopant. The present technique deposits an oxide layer during the ramp-up of the furnace that also deposits the nitride cap, thereby avoiding an extra process step. It also avoids the higher temperatures required for the prior-art technique of growing the oxide layer, resulting in lower oxygen precipitation due to the capping process and a greater yield of usable wafers.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile