Patent ID: 7033443

Claim:
A gas-cooled clamp for cooling a substrate residing thereon, comprising: a clamping plate having a plurality of protrusions on a top surface thereof and defining a plurality of gaps therebetween and a gap distance when the substrate resides thereon, wherein a cooling gas resides therein, wherein the clamping plate further comprises: a center portion over which the substrate resides; a peripheral portion; and an intermediate portion disposed between the center portion and the peripheral portion, the intermediate portion associated with a portion of the substrate; a guard ring surrounding and generally planar with the substrate when the substrate resides on the center portion of the clamping plate, the guard ring overlying the peripheral portion of the clamping plate, wherein the guard ring is configured to minimize thermal non-uniformity in the substrate due to edge effects; an isothermal gasket overlying the intermediate portion of the clamping plate, and operable to facilitate uniform heat transfer between the guard ring and the substrate; and a pressure control system operable to control a backside pressure of the cooling gas within the plurality of gaps between a first pressure and a second pressure, wherein a heat transfer coefficient of the cooling gas is primarily a function of pressure between the first and second pressures.