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:
Oct. 25, 2005
Filed:
Mar. 25, 2003
Gregory M. Wilson, Chesterfield, MO (US);
Jon A. Rossi, Mountainview, CA (US);
Charles C. Yang, Gilbert, AZ (US);
Gregory M. Wilson, Chesterfield, MO (US);
Jon A. Rossi, Mountainview, CA (US);
Charles C. Yang, Gilbert, AZ (US);
MEMC Electronic Materials, Inc., St. Peters, MO (US);
Abstract
A wafer is characterized in that the wafer has a non-uniform distribution of crystal lattice vacancies, wherein the concentration of crystal lattice vacancies in the bulk layer are greater than the concentration of crystal lattice vacancies in the front surface layer. In addition, the front surface of the wafer has an epitaxial layer, having a thickness of less than about 2.0 çm, deposited thereon. A process comprises heating a surface of a wafer starting material to remove a silicon oxide layer from the surface and depositing an epitaxial layer onto the surface to form an epitaxial wafer. The epitaxial wafer is then heated to a soak temperature of at least about 1175C. while exposing the epitaxial layer to an oxidizing atmosphere comprising an oxidant, and the wafer is cooled at a rate of at least about 10C./sec.