帽层对极紫外多层膜反射特性影响分析  

Analysis of the reflective performance of EUV multilayer under the influence of capping layer

作　　者：王洪昌[1] 王占山[1] 李佛生[1] 秦树基[1] 杜芸[1] 王利[1] 张众[1] 陈玲燕[1] 

机构地区：[1]同济大学精密光学工程技术研究所,物理系上海200092

出　　处：《物理学报》2004年第7期2368-2372,共5页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:60178021);上海市科技攻关项目(批准号:022261049);国家高技术研究发展计划(批准号:2002AA847050)资助的课题~~

摘　　要：介绍了在极紫外波段 ,利用帽层材料来减少多层膜反射镜因外部环境干扰而造成的反射率降低 ,使多层膜光学元件能够长时间稳定工作 .计算了在 13 9nm波长处Mo Si极紫外多层膜反射镜在表面镀制不同帽层材料时的理论最大反射率 ,利用单纯形调优法 ,对帽层和多层膜的周期厚度进行优化 ,同时把分层理论用于多层膜帽层优化 ,可使多层膜的反射率得到进一步提高 .分析了在加入帽层前后多层膜外层电场强度的分布变化情况 .In this paper we present a solution that addresses the reflectance loss due to oxidation. The solution is a capping layer (CL) that acts as an effective oxidation barrier when the multilayer (ML) is exposed to the extreme ultraviolet (EUV) light in the presence of water vapor, so that the optical element of multilayer can be used as long as possible. The theoretical reflectivity of ML Mo/Si EUV mirrors is calculated at 13.9nm under the different CL materials. The thicknesses of the CL and standard ML are optimized by the simplex method, meanwhile the reflectivity of ML can be further enhanced when the layer-by-layer theory is used. Finally the electric-field intensity distribution in the top layers of the ML is analyzed when the CL is added.

关 键 词：多层膜 反射率 帽层 极紫外 电场强度 吸波材料 

分 类 号：TB43[一般工业技术]