全频段亚纳米精度氟化钙材料加工  

Sub-nanometer precision optical fabrication of CaF_2 materials

作　　者：张春雷[1] 徐乐[1] 刘健[1] 马占龙[1] 王飞[1] 谷永强[1] 代雷[1] 彭石军[1] ZHANG Chun-lei＂ XU Le LIU Jian(Engineering Researc Fine Mechanics and GU Yong-qiang, DAI Lei, MA Zhan-long, WANG Fei, PENG Shi-jun h Center of Extreme Precision Optics, Changchun Institute of Optics, Physics, Chinese Academy of Sciences, Changchun 130033, China)

机构地区：[1]中国科学院长春光学精密机械与物理研究所超精密光学工程研究中心,吉林长春130033

出　　处：《光学精密工程》2016年第11期2636-2643,共8页Optics and Precision Engineering

基　　金：国家科技重大专项(No.2009ZX02205)

摘　　要：考虑用CaF_2材料制作投影光刻物镜可以明显提高其性能指标,本文研究了CaF_2材料加工工艺的全流程,以实现CaF_2材料的全频段高精度加工。首先,利用沥青抛光膜和金刚石微粉使CaF_2元件有较好的面形和表面质量。然后,优化转速、抛光盘移动范围、压力等加工工艺参数,并使用硅溶胶溶液抛光进一步降低CaF_2元件的高频误差,逐渐去除加工中产生的划痕并且获得极小中频误差(Zernike残差)和高频粗糙度。最后,在不改变CaF_2元件高频误差的同时利用离子束加工精修元件面形。对100mm口径氟化钙材料平面进行了加工和测试。结果表明:其Zernike 37项拟合面形误差RMS值可达0.39nm,Zernike残差RMS值为0.43nm,高频粗糙度均值为0.31nm,实现了对CaF_2元件的亚纳米精度加工,为研发高性能深紫外投影光刻物镜奠定了良好基础。When CaF_2 materials are used in projection lenses,the performance of the projection lenses can be improved greatly.This paper researches the process of CaF_2 crystal fabrication to realize its high precision optical fabrication in all wave bands.Firstly,the pitch lap and the diamond powder were used to get a relative better figure and surface quality of a CaF_2 element.Then,the technological parameters of the polishing lap,such as rotation speed,movement range and pressure were optimized,and the colloidal silica was used in polishing to reduce the high frequency errors in the CaF_2 element,remove the scratch in machining and to obtain a smaller mid-spatial error and smaller higher frequency roughness.Finally,the ion beam figuring technique was used to repair finely the surface figure of the element meanwhile maintaining the high frequency error in the CaF_2 element.The Experiments were conduct on a CaF_2 crystal plane with a diameter of 100 mm,and the results indicate that its 37 Zernike fit error and the Zernike residual error reach to 0.39 nm RMS and 0.43 nm RMS,respectively,and the roughness reaches to 0.31 nm on average.These results satisfy the nanometer machining requirements of the projection lens,and lay a basis for development of the high performance projection lenses.

关 键 词：氟化钙 投影光刻物镜 精密光学加工 亚纳米精度加工 离子束修形(IBF) 

分 类 号：TN305.2[电子电信—物理电子学] TH703[机械工程—仪器科学与技术]