Patent ID: 11887808

Abstract:
A thermal electrostatic clamp has a central electrostatic portion associated with a central region of a workpiece. A central body has a clamping surface and one or more electrodes are associated with the central body. One or more electrodes selectively electrostatically clamp at least the central region of the workpiece to the clamping surface based on an electrical current passed therethrough. One or more first heaters of the central body selectively heat the central electrostatic portion to a first temperature. A non-electrostatic peripheral portion associated with a peripheral region of the workpiece has a peripheral body encircling the central body, separated by a gap. The peripheral body is positioned beneath the peripheral region of the workpiece. The peripheral portion does not electrostatically clamp the peripheral region of the workpiece. One or more second heaters of the peripheral body selectively heat the non-electrostatic peripheral portion to a second temperature.