OPTICAL COMPONENT AND CLAMP USED IN LITHOGRAPHIC APPARATUS

摘要

Described herein is an optical element and a lithographic apparatus including the optical clement. The optical element includes a first member having a curved optical surface and a heat transfer surface; and a second member comprises at least one recess, the at least one recess sealed against the heat transfer surface to form at least one closed channel between the first member and the second member to allow fluid to flow therethrough for thermal conditioning of the curved optical surface. In an embodiment, regions of the heal transfer surface exposed to the at least one closed channel are positioned along a curved profile similar lo that of the curved optical surface.