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:
Nov. 20, 2001
Filed:
Mar. 08, 2000
Applicant:
Inventors:
Richard Joseph Phillips, St. Peters, MO (US);
Steven Jack Keltner, O'Fallon, MO (US);
John Davis Holder, Lake St. Louis, MO (US);
Assignee:
MEMC Electronic Materials, Inc., St. Peters, MO (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C30B 1/504 ;
U.S. Cl.
CPC ...
C30B 1/504 ;
Abstract
A process for preparing doped molten silicon for use in a single silicon crystal growing process is disclosed. Polysilicon is doped with barium and melted in a silica crucible containing less than about 0.5% gases insoluble in silicon. During melting and throughout the crystal growing process the barium acts as a devitrification promoter and creates a layer of devitrified silica on the inside crucible surface in contact with the melt resulting in a lower level of contaminants in the melt and grown crystal.