极紫外投影光刻光学系统

Optical system of extreme ultraviolet lithography

极紫外光刻(EUVL)是半导体工业实现32～16nm技术节点的候选技术,而极紫外曝光光学系统是EUVL的核心部件,它主要由照明系统和微缩投影物镜组成。本文介绍了国内外现有的EUVL实验样机及其系统参数特性;总结了EUVL光学系统设计原则,分别综述了EUVL投影光学系统和照明光学系统的设计要求;描述了EUVL投影曝光系统及照明系统的设计方法;重点讨论了适用于22nm节点的EUVL非球面六镜投影光学系统,指出了改善EUVL照明均匀性的方法。

Extreme UltraViolet Lithography（EUVL）has been regarded as a promising lithographic technology following ArF immersion lithography for the 32 nm hp node and beyond and the EUV optical exposure system consisting of a illumination system and a projection system is a key part in the EUVL.This paper introduces several kinds of EUVL tools at home and abroad and gives their optical specifications.Then,it summarizes the principles of optical design for EUVLs and reviews the design requirements for the illumination and projection systems,respectively.Finally,it describes the design methods of illumination and projection systems in EUVLs,especially,it discusses a aspheric 6-mirror projection optics which is suitable for 22 nm EVUL technology and gives the improvement method of illumination uniformity for the illumination system.