Abstract: 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 ?m or below.

Abstract: A two-layer structure retainer ring is capable of giving a uniform pressing force while uniting a first ring and a second ring more securely. A first ring 11 is formed with a pressed-and-fitted portion 11d over the full circumference of a lower surface 11c thereof and a second ring 12 is formed with a pressing-and-fitting portion 12d over the full circumference of an upper surface 12c thereof; the first ring 11 and the second ring 12 are united by pressing and fitting the pressing-and-fitting portion 12d into the pressed-and-fitted portion 11d; and an adhesive 13 is provided between the lower surface 11c of the first ring 11 and the upper surface 12c of the second ring 12.

Abstract: A retainer ring is provided which is capable of, effectively in practice, restraining the time taken for a break-in polish to the minimum. This retainer ring 8: is disposed inside of a holding head 4 in a CMP apparatus 1 which polishes a wafer W chemically and mechanically; has a ring shape so as to surround the periphery of the wafer W; presses a polish surface 3a of a polish pad 3; is made of an engineering plastic material such as PPS; and has a pressure surface 8a for pressing the polish surface 3a of the polish pad 3 whose surface roughness is a center-line average roughness (Ra) of 0.01 ?m or below.