Patent ID: 7646581

Claim:
An electrostatic chuck for attracting a flat substrate by an electrostatic force, the electrostatic chuck comprising: a body including an internal electrode for attracting the flat substrate by the electrostatic force provided therein, the body further including a first surface serving as an electrostatic attraction surface; a plurality of protrusions formed on the first surface of the body, each protrusion of the plurality of protrusions having a top surface; and one or more projections positioned on the top surface of each protrusion, and having an outer diameter smaller than the diameter of the protrusion, each of the one or more projections including a mounting surface on which the flat substrate is loaded, wherein a total area of the mounting surfaces of the one or more projections is equal to or larger than 0.01% and equal to or smaller than 2% of the area of the electrostatic attraction surface, a height of each projection of the one or more projections from the top surface of each protrusion is in a range equal to or larger than 3 μm and equal to or smaller than 6 μm, and a sum of a height of a protrusion of the one or more protrusions from the first surface of the body and the height of a projection of the one or more projections is in a range equal to or larger than 30 μm and equal to or smaller than 45 μm.