| 摘要 |
The invention describes an optical element with a the top layer which is transmissive for EUV radiation with wavelength lambda in the range of 5-20 nm, and wherein the structure of the top layer is a structure having a rms roughness value equal to or larger than lambda /10 for spatial periods equal to or smaller than lambda /2. Such a structure promotes transmission through the top layer to the optical element. <IMAGE> |
