Abstract: A retainer ring of a polishing head of a CMP apparatus facilitates the removal of contaminants, such as slurry debris, which have found their way into the polishing head. The retainer ring includes an annular ring body, and a plurality of contaminant outlets extending from the inner peripheral surface of the ring body to the outer peripheral surface of the ring body. Inner openings defined at the inner peripheral surface of the ring body and outer openings defined at the outer peripheral surface of the ring body by the contaminant outlets are horizontally elongated slots. Also, each of the contaminant outlets consists of a plurality of inner holes and an outer hole which is joined to the plurality of inner holes. The contaminant outlets occupy at least 30% of the radially innermost peripheral surface along a line extending circumferentially along the surface.

Abstract: A polishing head of a chemical and mechanical polishing apparatus includes a retainer ring which adheres more uniformly to a polishing pad. The retainer ring surrounds and protects a wafer chucked to the polishing head. The bottom surface of the retainer ring is inclined by a predetermined angle from the outer periphery thereof towards the inner periphery thereof. A resilient fixing plate disposed against the upper surface of the inner peripheral portion of the retainer ring provides a seal between the retainer ring and the carrier. Therefore, when the retainer ring is pressed against a polishing pad and the inner peripheral portion of the retainer ring is pushed downwardly due to the resiliency of the fixing plate, the retainer ring flexes such that uniform pressure is produced between the bottom surface of the retainer ring and the polishing pad. Hence, the wafer will be polished uniformly.