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:
May. 13, 2014
Filed:
Mar. 07, 2011
Juergen Schwandner, Garching, DE;
Thomas Buschhardt, Burghausen, DE;
Roland Koppert, Triftern, DE;
Siltronic AG, Munich, DE;
Abstract
A method for double-side polishing of a semiconductor wafer includes situating the semiconductor wafer in a cutout of a carrier that is disposed in a working gap between an upper polishing plate covered by a first polishing pad and a lower polishing plate covered by a second polishing pad. The first and second polishing pads each include tiled square segments that are formed by an arrangement of channels on the pads, where the square segments of the first pad are larger than the segments of the second pad. The square segments of the polishing pads include abrasives. During polishing, the carrier is guided such that a portion of the wafer temporarily projects laterally outside of the working gap. A polishing agent with a pH that is variable is supplied during polishing at a pH in a range of 11 to 12.5 during a first step and at a pH of at least 13 during a second step.