极紫外光刻物镜分组可视化界面设计优化

Extreme Ultraviolet Lithography Objective Design Based on Grouping and Graphical User Interface

高数值孔径(NA)、大视场极紫外光刻物镜光学系统是实现22 nm及以下技术节点产业化光刻系统的关键部件。通过对光刻物镜系统结构的分析,利用可视化对其初始结构进行分组构造。并在此基础上采用一种渐近式NA方法获得了弦长为26 mm,宽2 mm的弧形视场内复合波像差优于均方根(RMS)为λ/50的物镜系统。借助Q型多项式,使物镜光学元件非球面度低于45μm,最大口径小于400 mm,全视场波像差优于0.027λRMS,畸变优于1.5 nm。

Extreme ultraviolet lithography（EUVL） objective with high NA and large exposure field is the core component of lithography equipments for high volume manufacture（HVM） aiming at 22 nm node and beyond.The visual generation of the initial construction of EUVL objectives is presented based on the analysis of the valid objectives and grouping strategy. With alternation of step by step increasing NA and optimizations, λ/50 root mean square（RMS） composite wavefront error has been achieved in the 2 mm wide arc full field with a chord length of26 mm. By the aids of Q-type polynomials, the maximum asphericity and diameter of mirrors have been optimized less than 45 μm and 400 mm, respectively. And finally the full-field composite wavefront error is better than 0.027λ RMS and the distortion is less than 1.5 nm.