Patent attributes
A polishing apparatus is provided for polishing wafers at a high yield rate even if roll-off exists. The polishing apparatus polishes a wafer by applying a pressure between a polishing member (polishing pad) 201 and the wafer held by a holding member (top ring) 52 and moving the polishing member relative to the wafer. The polishing apparatus includes a top ring 52 for holding the wafer, a pressure adjusting mechanism for adjusting a supporting pressure with which the wafer is supported on a supporting surface by a retainer ring, and a control unit for controlling the pressure adjusting mechanism to bring the supporting pressure to a desired pressure based on a roll off quantity of the wafer. The top ring comprises an air bag 202 for pressing the wafer against the polishing pad, a retainer ring which surrounds the wafer, and an air bag for pressing the retainer ring.
