Abstract: Reflective optical components are disclosed for use in an X-ray optical system. The components (e.g., multilayer-film mirrors or reflective reticles) suppress contamination (e.g., carbon contamination) of their reflective surfaces during use. The multilayer film comprises alternating layers of first and second substances configured so as to confer high reflectivity to incident X-radiation (including perpendicularly incident radiation). The multilayer film includes a protective layer 1 formed of a material including a photocatalytic material) desirably formed on the uppermost layer of the multilayer film. If the optical component is a reticle, a patterned absorbing-body layer covers at least a portion of the multilayer film. A protective layer can be formed between the multilayer film and the absorbing-body layer, or in a blanketing manner over units of the absorbing-body layer and exposed portions of the multilayer film.

Abstract: Methods are disclosed for correcting the wave aberrations of light reflected from multilayer-film mirrors as used in, e.g., optical systems as used for EUV lithography (EUVL) apparatus. Wave aberrations are corrected by addition and/or removal of one or more layers (typically layer-sets) to and from, respectively, the surface of the multilayer film of the mirror. In certain embodiments, layer-removal is monitored in situ by any of several techniques. In other embodiments, mirror substrates are processed to a prescribed shape precision and surface roughness, followed by formation of the multilayer film and assembly of the mirrors into the intended optical assembly. The wave aberration is measured at operating wavelength. If the measured wave aberration is not within specifications, then the mirrors are corrected individually by selective removal and/or addition of layer-set(s). The corrected mirrors are reassembled and re-tested as an optical assembly. This cycle is repeated as required.