Chemical Mechanical Polishing Apparatus and Methods Using a Polishing Surface with Non-Uniform Rigidity

摘要

A chemical mechanical polishing apparatus includes a platen, a polishing pad affixed to a surface of the platen, and a polishing head configured to retain and rotate a wafer while pressing a surface of the rotating wafer against the polishing pad. A first portion of the polishing pad that engages the polishing head proximate the edge of the wafer provides less rigidity than a second portion of the polishing pad that engages a portion of the surface of the wafer. For example, the polishing pad and/or the platen may have a recess or other cushioning structure positioned proximate a locus of movement of a portion of the polishing head that supports the edge of the wafer.