光刻物镜六自由度调节支撑中耦合像差产生与抑制机理研究

项目名称： 光刻物镜六自由度调节支撑中耦合像差产生与抑制机理研究

项目编号： No.61504142

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 无线电电子学、电信技术

项目作者： 张德福

作者单位： 中国科学院长春光学精密机械与物理研究所

项目金额： 22万元

中文摘要： 光刻物镜中光学元件多自由度调节是系统像质补偿的重要措施，但其引入耦合像差的机制不详。最新研究发现,光学元件轴向调节时面形RMS值和Zernike系数随调节力线性变化。我们前期研究证实，限制偏心调节力向光学元件传递，可以降低耦合像差。据此，我们推测“六自由度调节支撑中，合理设计机构的刚度，可以减小光学元件自身变形和耦合刚体位移，从而减小调节引入的系统耦合像差”。本课题提出基于柔度矩阵法和耦合像差敏感度分析的六自由度调节支撑设计方法，揭示调节引入耦合像差的根源，通过结构刚度优化从设计上减小引入的耦合像差。用Fizeau相移干涉仪直接测试的光学元件刚体位移结果在线标定机构上传感器间接测试镜框的刚体位移，建立干涉仪和传感器测试结果之间的映射关系，最终在物镜中应用传感器在线检测，并应用闭环控制减小机构耦合刚体位移。本课题首次阐述光学元件多自由度调节与耦合像差产生机制的关系，为像质补偿提供一种新思路。

中文关键词： 光刻；投影物镜；像差；支撑；调节

英文摘要： Multi-DOF adjustment of optical elements is an important measure for system image quality compensation in lithographic projection lens, but the generation mechanism of coupling aberrations is unknown. The latest study found that the RMS value and Zernike coefficients of the surface figure vary linearly with the adjusting force during axial adjusting of optical elements. Our previous studies have demonstrated that coupling aberrations can be reduced when eccentric adjusting force is restricted to transmit from mount to the optical element. Accordingly, we speculate that the rational design of mechanism stiffness can reduce lens deformation and coupling rigid motion in the six DOF adjusting mount, thereby system coupling aberrations introduced by adjusting can be decreased. Design method of six DOF adjusting mount is established based on compliance matrix method and sensitivity analysis of coupling aberrations. The root of coupling aberrations introduced by adjusting can be revealed. Coupling aberrations can be decreased using stiffness optimization in designing process. Indirect testing results of mount rigid motion by sensor are calibrated online with direct testing results of optical element rigid motion by Fizeau phase-shifting interferometer. The mapping relationship between testing results of the interferometer and the sensor is found. Ultimately, sensor measurement is applied in projection lens online and closed-loop control is utilized to reduce the coupling rigid motion of the mechanism. This project describes the relationship between multi-DOF adjustment of optical elements and the generation mechanism of coupling aberrations for the first time. A new way of image quality compensation is provided.

英文关键词： lithography;projection lens;aberration;mount;adjustment