Patent ID: 6517421
Filing Date: 2003-02-11
Classification: B24B

Abstract:
A polishing head of a chemical and mechanical polishing apparatus for polishing a wafer, comprising:a housing; a carrier mounted to said housing so as to be movable up and down relative to said housing; a wafer chucking device including a wafer chuck body disposed beneath said carrier and mounted to said carrier so as to be movable up and down relative thereto independently of the up and down movement of said carrier relative to said housing, a wafer chucking surface dedicated to support a wafer during the polishing thereof, and biasing means for forcing said chuck body downwardly away from said carrier by exerting a downward biasing force uniformly across said chuck body; and a retainer fixed to said carrier so as to move up and down therewith, said retainer extending downwardly from said carrier and around said wafer chuck body so as to protect a wafer held against said wafer chucking surface, and said retainer being in sliding engagement with said wafer chuck body for guiding the wafer chuck body up and down relative to said carrier.