Yang, M.M.YangGatto, A.A.GattoKaiser, N.N.Kaiser2022-03-032022-03-032006https://publica.fraunhofer.de/handle/publica/21011010.1364/AO.45.000178We discuss the approaches to preserve the high-reflectance aluminum mirror for the vacuum-ultraviolet spectral region. Single fluoride and oxide layers, a homogeneous multilayer, and hybrid multilayer solutions are put forward. Single fluoride and oxide materials have achieved reflectance above 90% at 193 nm. Multilayer capping can provide reflectance of 93.4% at 193 nm, and a hybrid multilayer of fluoride and oxide can achieve reflectance above 90% to 160 nm.enUltraviolet, farcoatingmaterials and process characterizationoptical properties620535journal article