ELECTROSTATIC CHUCK EMPLOYING THERMOELECTRIC COOLING

摘要

An electrostatic chuck includes a conductive circular base (11) with an upper ring portion (12) forming a first pole piece electrically isolated from an annular portion (13) forming a second pole piece. The upper surface of the pole pieces have a dielectric material formed thereon and together form the electrostatic clamping surface for an article to be held thereon. The backside (18) is provided with an annular recess (19) containing a plurality of thermoelectric devices or modules (20) and intervening spokes. The devices are covered with a heat sink or cooling plate (25) through which a fluid such as water is circulated. A retaining back ring (28) covers the water plate which is secured to the base by bolts (29). Uniform pressure is applied to the water plate and modules by means of spring washers (30) inserted between back ring and water plate.