MIRROR, PROJECTION OBJECTIVE COMPRISING SUCH A MIRROR, AND PROJECTION EXPOSURE APPARATUS FOR MICROLITHOGRAPHY COMPRISING SUCH A PROJECTION OBJECTIVE

摘要

The invention relates to a mirror (la; la'; lb; lb'; lc; lc') comprising a substrate (S) and a layer arrangement, wherein the layer arrangement is designed in such a way that light (32) having a wavelength of less than 250 nm that is incident on the mirror (la; la'; lb; lb'; lc; lc') at at least an angle of incidence of between 0° and 30° is reflected with more than 20% of its intensity, and the layer arrangement comprises at least one surface layer system (?"') consisting of a periodic sequence of at least two periods (P3) of individual layers, wherein the periods (P3) comprise two individual layers composed of different materials for a high refractive index layer (?"') and a low refractive index layer (L'"), wherein the layer arrangement comprises at least one layer (G, SPL, B) composed of graphene. Furthermore, the invention relates to the use of graphene (G, SPL, B) on optical elements for reducing the surface roughness to less than 0.1 nm rms HSFR and/or for protecting the optical element in the EUV wavelength range against a radiation-induced irreversible change in volume of more than 1% and/or as a barrier layer for preventing interdiffusion between layers of so-called multilayer layer mirrors in the EUV wavelength range.