Patent ID: 8336891

Claim:
An electrostatic chuck comprising: a cooling device serving as an RF electrode, including a gas supply port penetrating through the cooling device, the gas supply port extending from one main surface to the other main surface, and a main counter bore portion having a diameter larger than that of the gas supply port, the main counter bore portion provided in an opening of the gas supply port; an arc prevention member buried in the main counter bore portion and made of an insulating member, wherein the arc prevention member has a gas path which is a tapered inner wall having an inner diameter extending concentrically in a direction from the cooling device towards the electrostatic chuck body, and wherein the gas path is configured to communicate with the gas supply port; and an electrostatic chuck body arranged on the cooling device, defining a work mounting surface on a top surface of the electrostatic chuck body, provided with a pore in communication with the gas supply port via the gas path.