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:
Jun. 01, 2004
Filed:
Feb. 11, 2002
Robert J. Falster, London, GB;
Martin Jeffrey Binns, St. Charles, MO (US);
Alan Wang, O'Fallon, MO (US);
MEMC Electronic Materials, Inc., St. Peters, MO (US);
Abstract
A thermal annealing process for producing a low defect density single crystal silicon wafer. The process includes thermally annealing a wafer having a first axially symmetric region which extends radially inwardly from the circumferential edge, contains silicon self-interstitials as the predominant intrinsic point defect and is substantially free of agglomerated interstitial defects and a second axially symmetric region which has vacancies as the predominant intrinsic point defect. The wafer is subjected to a thermal anneal at a temperature in excess of about 1000° C. in an atmosphere of hydrogen, argon or a mixture thereof to dissolve agglomerated vacancy defects present in the second axially symmetric region within a layer extending from the front side toward the central plane.