Wavelength separation from extreme ultraviolet mirrors using phaseshift reflection

Abstract

A generic design and fabrication scheme of Mo/Si multilayer-grating phaseshift reflector systems is reported. Close to optimized extreme ultraviolet (EUV, λ=13.5 nm) reflectance values up to 64% are demonstrated, while the diffractive properties can be exploited in spectral filtering applications. The results can contribute to a wavelength-unspecific solution for the suppression of λ>100 nm out-of-band radiation in EUV lithography.