| 摘要 |
An EUV mirror comprises a substrate and a multilayer arrangement applied on the substrate, which multilayer arrangement has a reflective effect for radiation having a wavelength λ from the extreme ultraviolet range (EUV) and comprises a multiplicity of layer pairs having alternating layers comprising a high refractive index layer material and a low refractive index layer material. The multilayer arrangement comprises: a periodic first layer group (LG1) having a first number N1 > 1 of first layer pairs, which are arranged in the vicinity of a radiation entrance side of the multilayer arrangement and have a first period thickness P1; a periodic second layer group (LG2) having a second number N2 > 1 of second layer pairs, which are arranged between the first layer group and the substrate and have a second period thickness P2; and a third layer group (LG3) having a third number N3 of third layer pairs, which are arranged between the first layer group and the second layer group. The first number N1 is greater than the second number N2. The third layer group has an mean third period thickness P3 which deviates from an average period thickness PM = (P1 + P2)/2 by a period thickness difference &Dgr;&Rgr;, wherein the period thickness difference &Dgr;&Rgr; substantially corresponds to the quotient of the optical layer thickness (λ/4) of a quarter-wave layer and the product of the third number N3 and cos(AOIM), wherein AOIM is the mean angle of incidence for which the multilayer arrangement is designed. |
