Optical element and optical system for EUV lithography and method of processing this optical system

摘要

The present invention relates to an optical element (50), which is added to a substrate (52), an EUV radiation reflection multilayer system (51) added to the substrate (52), and a multilayer system (51), Comprising a protective layer system (60) having at least a first and a second layer (57,58), the first layer (57) being arranged closer to the multilayer system (51) than to the second layer (58). . The first layer (57) functions as a diffusion barrier against hydrogen, and the solubility of hydrogen is lower than that of the second layer (58) that functions to absorb hydrogen. The present invention relates to an optical system for EUV lithography comprising at least one optical element (50) and in at least one layer (57,58,59) of the protective layer system (60) and / or in a multilayer system ( It also relates to a method of treating the optical element (50) to remove hydrogen contained in at least one layer (53, 54) of 51).