US Patent 6896602 Wafer holding ring for chemical and mechanical polisher

Disclosed is a wafer-holding ring adapted for holding a wafer on a chemical mechanical polishing apparatus, which can prevent damage to a wafer, possesses excellent abrasion resistance, and can reduce replacement work and consequently can realize mass production of polished wafers. In the wafer-holding ring for a chemical mechanical polishing apparatus, the surface of the wafer-holding ring at least in its portion, which can come into contact with a wafer, is formed of a resin composition comprising not less than 30% by weight of polybenzimidazole.