20080299882 | RETAINER-RING OF CMP (CHEMICAL MECHANICAL POLISHING) MACHINE - A retainer ring is provided which may restrain the time taken for a break-in polish to a minimum. This retainer ring may be disposed inside of a holding head in a CMP apparatus which polishes a wafer chemically and mechanically; may have a ring shape so as to surround the periphery of the wafer; may press a polish surface of a polish pad; may be made of an engineering plastic material such as PPS; and may have a pressure surface for pressing the polish surface of the polish pad whose surface roughness is a center-line average roughness (Ra) of 0.2 μm or below. | 12-04-2008 |