Abstract: At least three spring-mounted members disposed around the periphery of an aperture in a wafer-mounting plate are arranged to engage and securely hold edge portions of a semiconductor wafer to be processed. When the spring-mounted members are actuated toward the front side of the plate, a wafer can be freely moved into or out of the aperture from the back side of the plate by means of a vacuum chuck that contacts only the back side of the wafer. After a wafer to be held is inserted within the aperture, the actuated members are released. The released members move toward the back side of the plate and thereby engage the edges of the inserted wafer and exert radial holding forces thereon. The back side of a wafer so mounted is adapted to be brought into resilient engagement with a pedestal element in a processing chamber, thereby ensuring good thermal and electrical contact between the wafer and the pedestal element.