Tapered shadow clamp ring and method to provide improved edge exclusion

摘要

A method and apparatus is provided for clamping and shielding the edge of a substrate (12) useful in electronic device fabrication. A shadow ring is formed by an inward radial extension of the top surface of a generally annular shaped clamp ring (30). The shadow ring portion overhangs but does not contact the top surface of a substrate (12) being processed. A smoothly tapered substrate contact surface (58) extending from the outer diametrical extent of the shadow ring bottom surface to the bottom surface of the clamp ring (30) is sized and adapted to engage the outer edge (57) of a substrate (12). The substrate contact surface aligns the clamp ring to a substrate support member and a substrate to the substrate support member and the clamp ring (30) as the substrate (12) is lifted vertically.