EUV projection lens and optic system having the same

摘要

An EUV projection lens includes a substrate and concentric diffraction patterns on the substrate. The concentric diffraction patterns have an out-of phase height with respect to EUV light and include a material through which the EUV light has a transmittance higher than about 50% at the out-of phase height. The EUV projection lens has a high first order diffraction light efficiency and an optic system having the EUV projection lens has a high resolution.