Polishing head of a chemical and mechanical polishing apparatus for polishing a wafer

Abstract

A polishing head of a chemical and mechanical polishing apparatus can uniformly polishing a wafer by sticking the wafer firmly and with uniform pressure to a polishing pad. The polishing head includes a housing through which air is supplied and discharged from the head. A carrier is connected to the housing so as to be movable up and down relative to the housing. A wafer chucking device is mounted to the carrier. The wafer chucking device includes a wafer chuck body movable up and down relative to the carrier. The wafer chuck body defines a vacuum chamber therein for use in adhering a wafer to the wafer chucking device. A retainer is mounted to the periphery of the carrier, guides the wafer chuck body in its up and down movement relative to the carrier, and protects the wafer chucked by the wafer chucking device. A biasing member is used to exert a downward biasing force uniformly on the wafer chuck body. Because the wafer is held fast against the wafer chuck body, and is pressed in such a state against a polishing pad by the biasing force exerted uniformly on the wafer chuck body independently of the force used to position the retainer against the polishing pad, the wafer is forced against the polishing pad uniformly.