摘要 |
A method aleviating blistering, cracking and chipping in topmost layers of a multilayer system exposed to reactive hydrogen, when producing a reflective optical element (50) having a maximum reflectivity at an operating wavelength of 5 nm to 20 nm. A multilayer system (51) composed of 30-60 stacks (53) is applied to a substrate (52). Each stack has a layer (54) of thickness dMLs composed of a high refractive index material and a layer (55) of thickness dMLa composed of a low refractive index material. The thickness ratio is dMLa/(dMLa+dMLs)=ΓML. Two to five further stacks (56) are applied to the multilayer system. at least one further stack having a layer (54) of thickness ds composed of a high refractive index material and a layer (55) of thickness da composed of a low refractive index material, wherein the thickness ratio is da/(da+ds)=Γand whereinΓ≠ΓML. |