A polishing apparatus is used for polishing a workpiece such as a semiconductor wafer to a flat mirror finish. The polishing apparatus comprises a turntable having a polishing surface, a top ring for holding a workpiece and pressing the workpiece against the polishing surface to polish the workpiece,...http://www.google.de/patents/US6682408?utm_source=gb-gplus-sharePatent US6682408 - Polishing apparatus
