Reflective optical element for euv lithography

Abstract

In order to prevent delamination of a reflective coating from the substrate under the influence of reactive hydrogen, a reflective optical element (50) for EUV lithography is provided, which has a substrate (51) and a reflective coating (54) for reflecting radiation in the wavelength range of 5 nm to 20 nm. A functional layer (60) is arranged between the reflective coating (54) and the substrate (51). With the functional layer, the concentration of hydrogen in atom % at the side of the substrate facing the reflective coating is reduced by at least a factor of 2.

Dependencies are inferred from the claim text.