Patent attributes
An electrostatic chuck assembly includes a ceramic body having a wafer placement surface that is a circular surface, and an F/R placement surface that is formed around the wafer placement surface and is positioned at a lower level than the wafer placement surface, a wafer attraction electrode embedded inside the ceramic body and positioned in a facing relation to the wafer placement surface, an F/R attraction electrode embedded inside the ceramic body and positioned in a facing relation to the F/R placement surface, a concave-convex region formed in the F/R placement surface to hold gas, a focus ring placed on the F/R placement surface, and a pair of elastic annular sealing members arranged between the F/R placement surface and the focus ring on the inner peripheral side and the outer peripheral side of the F/R placement surface, and surrounding the concave-convex region in a sandwiching relation.

