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. 11, 2014
Filed:
Mar. 08, 2011
Juergen Schwandner, Garching, DE;
Roland Koppert, Triftern, DE;
Juergen Schwandner, Garching, DE;
Roland Koppert, Triftern, DE;
Siltronic AG, Munich, DE;
Abstract
A method of polishing a semiconductor wafer includes applying a polishing pad to the semiconductor wafer so as to subject the semiconductor wafer to a polishing process and supplying an aqueous polishing agent solution between the polishing pad and the semiconductor wafer. The polishing pad includes fixedly bonded abrasives of SiOwith an average grain size in a range of 0.1 to 1.0 μm. The aqueous polishing agent solution comprising an alkaline component, being free of solid materials and having a variable pH value in a range of 11 to 13.5. The aqueous polishing agent solution is maintained at a pH value of less than 13 during the polishing process and the pH value of the aqueous polishing agent solution is increased to a range of 13 to 13.5 so as to end the polishing process.