PLATEN ASSEMBLY FOR A VACUUM PROCESSING SYSTEM

摘要

A platen assembly (66) for holding a semiconductor wafer (30) for vacuum processing. The platen is a substantially solid, circular plate (194) which is surrounded by a movable clamp assembly (192) in the form of a ring having formed thereon a first set of projections (257, 258) for initially receiving a wafer above the plate, and a second set of projections (256) spaced axially from the first set for clamping the wafer to the plate. The ring is formed of two parts (251, 252) spaced apart axially and connected by spring members (254). A slot (255) is formed in the ring to permit the entry of wafers between the sets of projections. The clamp assembly is moved between a water receiving position and a clamping position by an annular fluid cylinder (228) and piston (232) assembly. The fluid cylinder and piston assembly includes bellows seals acting between the cylinder and piston rods (238) to maintain the vacuum integrity of the system.