Patent ID: 6840845

Claim:
A wafer polishing apparatus for polishing a wafer, comprising: a polishing pad; and a rotatable holding head which holds the wafer and presses the wafer against the polishing pad, wherein the holding head comprises: a carrier which presses the wafer against the polishing pad through a pressurized air layer; a retainer ring arranged at a circumference of the carrier; a holding head body including a carrier pressing device through which a pressing force is transmitted to the carrier, and a shaft extending from the holding head body and the carrier, wherein the carrier pressing device includes an air bag of a flexible sheet material in which a pressing surface area of the air bag is 50% or smaller of an area of the wafers, wherein the carrier includes a central recess into which a shaft end is positioned, and wherein the central recess includes a locking pin extending radially inward from a circumferential wall of the recess into engagement with the end of the shaft to enable rotation of the carrier.