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. 05, 1996
Filed:
May. 18, 1994
Vepa Krishna, St. Charles, MO (US);
Michael S Wisnieski, O'Fallon, MO (US);
Lois Illig, Troy, MO (US);
MEMC Electronic Materials, Inc., St. Peters, MO (US);
Abstract
A method of rough polishing a semiconductor wafer to reduce roughness on a surface of the wafer prior to finish polishing the wafer by applying a polishing solution to a polishing material, contacting the polishing material and the polishing solution with the surface of the wafer as the wafer moves relative to the polishing material to reduce low frequency surface roughness of the wafer, applying a second polishing solution to the polishing material, and contacting the polishing material and the second polishing solution with the surface of the wafer as the wafer moves relative to the polishing material to further reduce the low frequency surface roughness, wherein the wafer has an average surface roughness not greater than 1.0 nm Ra, as measured on a 1 mm.times.1 mm scan with an optical interferometer, after being rough polished.