摘要
针对极紫外光刻照明系统光能利用率低的问题,设计了一套高光能利用率极紫外光刻波纹板照明系统。该系统中波纹板面形采用柱面镜阵列,降低了加工难度;并且根据波纹板反射光线的特性,确定了由修正型复合抛物面聚光镜与二次曲面反射镜组作为中继镜组的结构。整个系统仅采用四片反射镜且其中两片反射镜为掠入射,与传统的极紫外光刻照明系统相比,有效地提高了系统的光能利用率。对一套数值孔径0.33的极紫外光刻投影物镜,给出了与之相匹配的波纹板照明系统设计实例。仿真结果表明,系统的光能利用率可达39.7%,掩模上弧形照明区域扫描方向的积分不均匀度小于2.7%,验证了该设计的可行性和有效性。
A high- efficiency ripple plate illumination system for extreme ultraviolet（EUV） lithography is proposed. A cylindrical mirrors array is used as ripple plate mirror to simplify the system. By analyzing the characteristics of reflection on ripple plate, we design a relay system with a modified compound parabolic concentrator and two conic mirrors to reduce the efficiency loss caused by excessive number of reflective mirrors. Compared with the traditional EUV lithography illumination system, it greatly improves the system′s efficiency. A design example for a numerical aperture（NA） 0.33 projection objective is given and the efficiency of the illuminator is 39.7% while the slit non- uniformity of the scanning energy distribution is 2.7% in a prescribed arc area, which proves the feasibility of the design.
出处
《光学学报》
EI
CAS
CSCD
北大核心
2015年第3期294-300,共7页
Acta Optica Sinica
基金
国家科技重大专项(2012ZX02702001-002)
关键词
光学设计
波纹板照明系统
反射系统
极紫外光刻
optical design
ripple plate illumination system
catoptric system
extreme ultraviolet lithography
