WAFER CLAMP FLATTENING

摘要

The present development relates to lithographic devices, in particular to wafer clamps used to clamp a wafer.Today an iterative process flattens wafer clamps. Each iteration of the flattening process of the wafer clamp involves a measurement of the wafer flatness at a measurement stand and a flattening process at a correction/machining stand. With each iteration, the wafer clamp is transported between the measurement stand and the correction/machining stand.Transport between a measurement stand and a correction stand may cause many risks on damage, contamination, may require cleaning at each iteration and may take substantial time of a production capacity to handle, transport and More these wafer clamps. It may also limit a capability of correction of wafer un-flatness, because it may be difficult to bring back the wafer clamp in the exact same state during the correction processes, as it is measured.