Carrier head with reduced moment wear ring

摘要

A work piece carrier head for a CMP or other polishing apparatus is configured to eliminate the slow band associated with the polishing of the surface of a work piece. The carrier head includes a wear ring that is positioned circumferentially about the work piece and that together with the work piece is pressed against a moving polishing pad. The wear ring is resiliently coupled to the body of the carrier head in a manner to avoid any overturning moment on the ring caused by the frictional force of the polishing pad against the wear ring.