ASML Holding N.V.
Membranes for use within a lithographic apparatus and a lithographic apparatus comprising such a membrane

Abstract:

A membrane transmissive to EUV radiation, which may be used as a pellicle or spectral filter in a lithographic apparatus. The membrane has one or more high doped regions wherein the membrane is doped with a dopant concentration greater than 10.sup.17 cm.sup.-3, and one or more regions with low (or no) doping. The membrane may have a main substrate having low doping and one or more additional layers, wherein the high doped regions are within some or all of the additional layers.