摘要 |
A limiting factor in the operation of EUV lithographic devices is the lifetime or the reflectivity of the reflective optics that is reduced by contamination with carbon-containing substances. Protective coatings that are resistant to oxidation or are inert against water are already known. According to the invention it is proposed to deposit protective coatings on, for example, multilayers that suppress the growth of carbon-containing substances in combination with layers that are inert against residual gas atmosphere and energy input. Even with a long operating time a high reflectivity is thereby retained. The protective coatings may be deposited by electron-beam vaporization, magnetron- or ion-beam sputtering.
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