Patent ID: 8422193

Claim:
An electrostatic clamp for clamping a workpiece, the electrostatic clamp comprising: a clamping plate, comprising: an annulus comprising a first layer having a first surface associated therewith, wherein the first surface is configured to contact a peripheral region of a surface of the workpiece; a central disk comprising a second layer having a second surface, wherein the annulus generally encircles the central disk, and wherein the second surface is generally recessed from the first surface, therein generally defining a gap between the second surface and the surface of the workpiece; and one or more backside gas delivery apertures in fluid communication with a gas supply and positioned proximate to an interface between the annulus and the central disk; a first electrode associated with the annulus, wherein the first electrode is electrically connected to a first voltage potential; and a second electrode associated with the central disk, wherein the second electrode is electrically connected to a second voltage potential, and wherein the first electrode and second electrode are electrically isolated from one another.