Pedestal of a load-cup which supports wafers loaded/unloaded onto/from a chemical mechanical polishing apparatus

Abstract

A pedestal of a load-cup for supporting wafers loaded onto and being unloaded from a chemical mechanical polishing (CMP) apparatus includes a pedestal plate, and a pedestal film which extends over only a limited area at the upper surface of the pedestal plate. This area includes the regions directly around the fluid ports provided in the pedestal plate for vacuum-chucking the wafers and spraying deionized water. The pedestal plate may have a cross-shaped part, the entirety of which bears the fluid ports. The pedestal film may include annular members each extending around only a respective one of the fluid ports, or one or more members each extending radially around several of the fluid ports. By offering a rather limited contact area to the wafer supported on the pedestal, the pedestal film reduces the amount of contaminants which could be transferred to the wafer surface in contact therewith.