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:
Feb. 20, 2001
Filed:
Dec. 29, 1999
Applicant:
Inventors:
David Zhang, Ballwin, MO (US);
Sharon Brumer, St. Charles, MO (US);
Henry F. Erk, St. Louis, MO (US);
Assignee:
MEMC Electronic Materials, Inc., St. Peters, MO (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L 2/1302 ;
U.S. Cl.
CPC ...
H01L 2/1302 ;
Abstract
A multi-step polishing process for producing dopant-striation-free semiconductor wafers. The process includes polishing a surface of the wafer using a sodium stabilized colloidal silica slurry, an amine accelerant, and an alkaline etchant, polishing the surface of the wafer using a sodium stabilized colloidal silica slurry and an alkaline etchant which is substantially free of amine accelerants, and polishing the surface of the wafer using an ammonia stabilized colloidal silica slurry and an alkaline etchant which is substantially free of amine accelerants.