Uniform gas cushion wafer support

摘要

A workpiece is supported on a gas cushion to reduce mechanical stresses on the workpiece during processing. A plenum having a workpiece support flange for receiving the workpiece is connected to a gas supply. When gas flows into the plenum and pressure increases sufficiently to lift the workpiece, the workpiece is lifted and the gas flows out of the plenum between the flange and the workpiece edge. The workpiece is thus supported above the flange by the gas during processing.