光刻机自由照明用微反射镜阵列设计  

Design of Micromirror Array for Freeform Illumination in Lithography Systems

作　　者：张敬巍 胡敬佩 孙梦婕 胡家豪 曾爱军[1,2] 黄惠杰 Zhang Jingwei;Hu Jingpei;Sun Mengjie;Hu Jiahao;Zeng Aijun;Huang Huijie(Laboratory of Information Optics and Optoelectronic Technology Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China;University of Chinese Academy of Sciences,Beijing 100049,China;Shanghai Light-Wonder Optics Co.,Ltd.,Shanghai 201800,China)

机构地区：[1]中国科学院上海光学精密机械研究所信息光学与光电技术实验室,上海201800 [2]中国科学院大学,北京100049 [3]上海镭望光学科技有限公司,上海201800

出　　处：《中国激光》2024年第22期43-50,共8页Chinese Journal of Lasers

基　　金：上海市集成电路科技专项支撑(220501110600)。

摘　　要：光源掩模联合优化是28 nm及以下节点浸没式光刻机提高光刻系统分辨率的关键技术,自由照明系统中的微反射镜阵列是确保该技术实现的核心部件。提出了一种单蛇形梁微反射镜结构,其省去了外部可动框架配置,仅在两个固定电极的驱动下即能实现镜面的二维偏转,简化了驱动模块。同时设计了一种阶梯式驱动电极结构对微反射镜单元进行优化,当在双驱动电极上均施加55 V电压时,最大偏转角度达到了26.2 mrad,与最大偏转角为17.8 mrad的初始驱动电极结构相比,此时对应的可动极板下拉位移提高了46.6%。Objective As a critical resolution enhancement method, source and mask optimization(SMO) technology significantly improves imaging quality and process window performance by optimizing the source shape and mask pattern simultaneously through multiple iterations. The existing approaches for implementing optimized illumination modes with high degrees of freedom are typically based on two methods: the diffractive optical element(DOE) and the micromirror array(MMA). The limitations of the DOE-based method include the inflexibility of the illumination modes and partial energy loss. The MMA-based method can flexibly achieve arbitrary source shapes by modulating the tilt angles of the thousands of micromirrors. However, current MMA manufacturing faces challenges for the large-scale integration of micromirrors. Existing two-dimensional(2D) mirrors mainly rely on external movable frames and multiple electrodes, which complicate the manufacture of the MMA. In this study, we report a 2D micromirror mechanical structure with a single serpentine beam and two fixed electrodes. We also propose an optimized electrode structure to reduce the driving voltage.We believe that the designed micromirror array has great potential for application in illumination systems.Methods In this study, a 2D micromirror machine with a serpentine beam is designed. A movable plate is supported by the beam fixed to an anchor on the substrate. The micromirror surface is coated with the high reflective layer of a 193 nm laser to reduce the energy loss in the lithography system. Two symmetrically distributed electrode structures are placed below the movable plate. The micromirror employs a serpentine beam as the mechanical force driving part, which is actuated by the electrostatic force between the fixed electrodes and movable plate. The driving process of the micromirror is sequentially simulated and analyzed. Subsequently, a stepped electrode structure is designed to reduce the driving voltage. In addition, based on the established mechanical model of t

关 键 词：光刻机系统 自由照明系统 微反射镜阵列 单蛇形梁微反射镜 

分 类 号：O439[机械工程—光学工程]