Abstract: 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 wafer 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.

Abstract: A sealing arrangement for a vacuum processing system for semiconductor wafers which is effective to apply a sealing force to a valve element (66) between chambers of the processing system. The valve element is defined by a platen which holds wafers (30) for transfer between a horizontal receiving position within a staging chamber (14) to a vertical position within a processing chamber (16-19). The sealing arrangement includes a pair of toggle mechanisms (268) which are manually operable from outside the staging chamber and which, in conjunction with the closing force applied by the platen operating mechanism (165) are effective to maintain vacuum integrity within the staging chamber when the process chamber is at atmospheric pressure or removed for servicing.