Chemical mechanical polishing apparatus and method having a rotating retaining ring

摘要

A polishing apparatus (100) and method for polishing and planarizing a substrate (105) is provided that achieves a high-planarization uniformity across the substrate. In one embodiment, the polishing head (140) includes a carrier (155), a subcarrier (160) carried by the carrier and adapted to hold the substrate (105) during a polishing operation and a retaining ring (170) rotatably disposed about the subcarrier. The retaining ring (170) has a lower surface (205) that is substantially flush with the surface of the substrate (105) and is in contact with a polishing surface (125) during the polishing operation. The retaining ring (170) is capable of rotating relative to the substrate (105) held on the subcarrier (160) to inhibit non-planar polishing of the surface of the substrate. In another embodiment, the polishing head (140) further includes a backing ring (210) in a facing relationship with an upper surface (255) of the retaining ring (170) and separated from the retaining ring by a bearing (260).