Patent ID: 7667943

Claim:
An electrostatic chuck comprising: an electrode; a polyimide insulating layer with the electrode embedded therein and having a surface to come in contact with a workpiece to be held; and a silicone rubber layer formed on the insulating layer surface by curing a silicone rubber composition comprising 100 parts by weight of an organopolysiloxane having at least two silicon-bonded alkenyl groups in a molecule, 5 to 100 parts by weight of a filler consisting of fumed silica having a specific surface area of 100 to 400 m 2 /g as measured by the BET method, and a curing agent in such an amount that it cures the silicone rubber composition, the silicone rubber layer being free of a filler having an average particle size of at least 0.2 μm other than the fumed silica.