极紫外多层膜技术研究进展

在极紫外波段,任何材料都表现出极强的吸收特性,因此,采用多层膜实现高反射率是构建正入射式光学系统的唯一途径。本文总结了极紫外多层膜的发展进程,叙述了制备极紫外多层膜的关键技术(磁控溅射、电子束蒸发、离子束溅射)以及它们涉及的相关设备。由于多层膜反射式光学元件主要应用于极紫外光刻与极紫外天文观测,文中重点讨论了极紫外光刻系统对多层膜性能的要求,镀膜过程中的面形精度和热稳定性等问题;同时介绍了极紫外天文观测中使用的多层膜的特点,特别讨论了多层膜光栅的制备技术和亟待解决的问题。

Progress in EUV multilayer coating technologies

All materials have strong absorptin properties in Extreme Ultra Violet(EUV) region. Therefore, it is an only approach to construct a normal incidence optical system by using multilayer coatings to improve its reflectivity. In this paper, the development of EUV multilayer coatings is introduced and the key technologies for fabricating multilayer coatings(magnetron sputtering, electron beam evaporating, ion beam sputtering) and their relative apparatus are described. As multilayer coating reflective optical elements are mainly used in the EUV lithography and EUV astrophysics, it lays the emphasis on the study on the characteristics of multilayer coatings in EUV lithographic equipment, and the surface accuracy and thermal stability in coating processing. Furthermore, it also gives the special multilayer coatings for astronomical observations and discusses the fabrication of multilayer coating gratings and several problems to be solved.