abstract |
Optical elements such as multilayered EUV mirrors are provided with protective capping layers of diamond-like carbon (C), boron nitride (BN), boron carbide (B 4 C), silicon nitride (Si 3 N 4 ), silicon carbide (SiC), B, Pd, Ru, Rh, Au, MgF 2 , LiF, C 2 F 4 and TiN and compounds and alloys thereof. The final period of a multilayer coating may also be modified to provide improved protective characteristics. |