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:
Mar. 28, 1995
Filed:
May. 17, 1993
Robert Falster, Milan, IT;
Giancarlo Ferrero, Turin, IT;
Graham Fisher, Chesterfield, MO (US);
Massimiliano Olmo, Novara, IT;
Marco Pagani, Novara, IT;
MEMC Electronic Materials, SpA, Novara, IT;
Abstract
A process for treatment of a silicon wafer to achieve therein a controlled distribution of the density of oxygen precipitate nucleation centers. In the process, one face of the wafer is shielded and the other, unshielded, face of the wafer is exposed to an atmosphere which contains nitrogen or a nitrogen compound gas and which has an essential absence of oxygen during a rapid thermal treatment at a temperature of at least about 1175.degree. C. The process generates nucleation centers which serve as sites for the growth of oxygen precipitates during a subsequent heat treatment and which have a peak density proximate the unshielded face of the wafer.