Patent ID: 7044838
Filing Date: 2006-05-16
Classification: B24B

Abstract:
1. A method of planarizing a semiconductor wafer, said method including: supporting a back-side surface of said wafer with a wafer support subcarrier; applying a polishing force against said support subcarrier to press a front surface of said wafer against a polishing pad; disposing a retaining ring that defines a chamfered outer edge about a portion of said wafer support subcarrier and said wafer so as to restrain movement of said wafer from said support subcarrier during polishing, said chamfered outer edge including a transition region between a first surface substantially parallel to said pad and a fourth surface substantially perpendicular to said pad, said transition region presenting a second surface at a first angle relative to said first surface and a third surface at a second angle relative to said fourth surface, wherein said first and second angles are each 20±4 degrees; and applying a pad conditioning force to said retaining ring to press a front surface of said retaining ring against said polishing pad.