Method for producing a reflective optical element for euv-lithography

A method for producing a reflective optical element for extreme ultraviolet (EUV) lithography, which element has a maximum reflectivity at an operating wavelength in the range of 5 nm to 20 nm, comprising:

• applying to a substrate a multilayer system composed of thirty to sixty stacks arranged one above another, wherein each stack has a layer having a thickness dMLs composed of a material having a higher real part of the refractive index at the operating wavelength, and a layer having a thickness dMLa composed of a material having a lower real part of the refractive index at the operating wavelength, wherein the thickness ratio is dMLa/(dMLa+dMLs)=ΓML,
• applying two, three, four or five further stacks to the multilayer system, said at least two further stacks each having a layer having a thickness ds composed of a material having a higher real part of the refractive index at the operating wavelength, and a layer having a thickness da composed of a material having a lower real part of the refractive index at the operating wavelength, wherein the thickness ratio is da/(da+ds)=Γ and Γ>1.2*ΓML or Γ<0.8*ΓML.