Methods using active retainer rings for improving edge performance in CMP applications

摘要

An invention improves edge performance in chemical mechanical polishing processes. A method operation provides a wafer head above a wafer. The wafer head includes a first active retaining ring capable of extension and retraction. Another operation provides a polishing belt below the wafer head, and provides below the polishing belt a platen having a second active retaining ring capable of extension and retraction. Another operation controls positions of the first active retaining ring and the second active retaining ring to provide positional control for the polishing belt, thus adjusting and controlling the removal rate at the edge of the wafer.