光学学报, 2011, 31 (8): 0805001, 网络出版: 2011-07-29
基于光闸叠栅条纹的纳米检焦方法
Moiré Fringe-Based Focusing-Test Scheme for Optical Projection Lithography
光学测量 焦面检测 叠栅条纹 光弹调制 横向剪切分束器 optical measurement focusing test Moiré fringe photoelastic modulation Savart plate
摘要
针对投影光刻机短波长、大数值孔径、短焦深的特点,讨论了一种基于光闸叠栅条纹的纳米检焦方法。该方法采用三角测量的基本原理,利用双光栅光闸叠栅条纹的光强调制机理,并结合像横向剪切器和光弹调制的光学特性,建立了单个光栅周期内焦面位移量和输出光能量线性关系。其具有非接触、强实时性和高稳健性的特点,经理论分析和模拟测试,达到纳米量级的检测精度,可以满足投影光刻高精度、实时、非接触焦面测量的要求。
Abstract
Based on the short wavelength, large numical operture, and short focal depth of optical projection lithography, a focusing method is presented based on Moiré fringe and the principle of triangulation. By analyzing the optical properties of photoelastic modulation and Savart plate, combining the intensity modulation mechanism of dual-grating Moiré fringes, the linear relation between focal plane displacement and output light energy is established in a single grating period. After theoretical analysis and simulated test, it shows precision at nanometer scale with the property of non-contacting, high robustness and well time efficiency, meeting the demands of focusing test in projection lithography.
严伟, 李艳丽, 陈铭勇, 王建. 基于光闸叠栅条纹的纳米检焦方法[J]. 光学学报, 2011, 31(8): 0805001. Yan Wei, Li Yanli, Chen Mingyong, Wang Jian. Moiré Fringe-Based Focusing-Test Scheme for Optical Projection Lithography[J]. Acta Optica Sinica, 2011, 31(8): 0805001.