光学 精密工程, 2013, 21 (8): 2000, 网络出版: 2013-09-06
基于运动学支撑的透镜光学表面面形及其复现性
Optical surface figure of lens under kinematic mount apparatus and its reproducibility
投影物镜 运动学支撑结构 光学表面面形 夹持力 复现性 有限元法 Zernike多项式 projection objective kinematic mount apparatus optical surface figure clamping force reproducibility finite element method Zernike polynomials
摘要
根据高精度投影光刻物镜的特点, 提出了一种运动学支撑结构, 并采用实验结合有限元分析的方法研究了该支撑结构引起的透镜光学表面变形以及重复装配过程中透镜光学表面面形的复现性。首先, 介绍了运动学支撑结构的原理及镜面变形分析的方法。然后, 应用Zernike多项式拟合实测和有限元分析得到的面形, 并用两种方法对运动学支撑结构夹持力引起的透镜光学表面面形进行对比, 以验证有限元分析模型的正确性。同时, 分析了考虑重力情况下运动学支撑结构导致的透镜光学表面变形。最后, 用实验的方法测量了运动学支撑结构在重复装配过程中透镜光学表面面形的复现性。实验和分析结果显示, 由运动学支撑结构夹持力引起的透镜光学表面面形均方根(RMS)值的实测值为1.004 nm, 分析值为0.974 nm, 夹持力及重力综合作用下导致的透镜表面Fringe Zernike拟合面形RMS值为2.538 nm, 产生的主要像差为离焦、初级三叶像差和二级三叶像差, 重复装配过程中引起的透镜光学表面面形的复现性标准差为0.645 nm。得到的结果表明, 所设计的运动学支撑结构能够保证透镜光学表面面形在重复装配过程中有良好的复现性。
Abstract
On the basis of characteristics of high precision projection objectives, a kinematic mount apparatus was proposed. In order to evaluate the performance of the kinematic mount apparatus, the geometrical deformation and the optical surface figure reproducibility of a lens caused by the kinematic mount apparatus were investigated with Finite Element Method(FEM) and experiments. Firstly, the working principle of kinematic mount apparatus was introduced and the analysis method for surface deformation was also given. Then, surface deformations from the experiment and the finite element analysis were fitted with Zernike polynomials and obtained results by the two methods were compared for verifying the feasibility of the FEM. Furthermore, the optical surface deformation of the lens caused by the kinematic mount apparatus under the gravity was also explored. Finally, the reproducibility of optical surface figure of lens during a repeating assembly of the kinematic mount apparatus was also given with the experiment method. The experiment and FEM results indicate that RMS values caused by clamping force are 1.004 nm and 0.973 nm, respectively, and that induced both by clamping force and gravity are 2.538 nm. Moreover, the Power, Pre Trefoil and Sec Trefoil are the main aberrations of surface deformation, and the optical surface figure reproducibility of lens is 0.645 nm during the repeating assembly. These results mean that the kinematic mount apparatus can keep the optical surface figure in a good reproducibility.
于新峰, 巩岩, 倪明阳, 秦硕. 基于运动学支撑的透镜光学表面面形及其复现性[J]. 光学 精密工程, 2013, 21(8): 2000. YU Xin-feng, GONG Yan, NI Ming-yang, QIN Shuo. Optical surface figure of lens under kinematic mount apparatus and its reproducibility[J]. Optics and Precision Engineering, 2013, 21(8): 2000.