The heating body 196 is preferably formed from quartz, although the body 196 can alternatively be made from materials, such as sapphire and alumina, or aluminum as in the electrostatic chuck manufactured by Tokyo Electron Limited, or the one disclosed in U.S. Pat. No. 5,310,453 entitled ???Plasma process method using an electrostatic chuck??? and assigned to Tokyo Electron Yamanashi Limited (Fukas