Multilayer optics in the extreme ultraviolet and soft X-ray range is reviewed in the paper. The advantages and difficulties are pointed out.
综述了极紫外和软x射线多层膜光学及其应用，指出了极紫外和软x射线光学的优点和难点。
2
A new design of off-axis five mirrors optics was presented which was used to extreme-ultraviolet lithography. It was very suit for the commercialization at optical quality and free work distance.