点衍射干涉仪波面参考源误差及公差分析

Analysis on error and tolerance for the wavefront reference source of point diffraction interferometer

为了保留光纤点衍射干涉仪容易对准以及衍射光束易于控制的优点,同时又能实现大数值孔径(NA)光学系统的检测,设计了一种新型的波面参考源(WRS),它保留了光纤点衍射和微孔点衍射的优点,可满足大NA极紫外光刻物镜系统波像差检测的要求。本文在分析各种误差的基础上,搭建了WRS原理光路并对WRS的系统误差标定算法进行详细的研究,得到WRS标定时旋转平台的角度公差为0.5°,跳径时偏离系数为0.5%。这一新型WRS误差分析及标定对于实现高精度的检测具有十分重要的意义,最终为实现WRS系统误差标定提供理论基础。

To keep the advantages of fiber point diffraction interferometer which is easy to align and control the diffracted light, we design a new wavefront reference source （WRS）.WRS can keep the advantages of fiber point diffraction interferometer and pin-hole point diffraction interferometer , and it also can be used to test the wavefront aberration of larger NA optical system for Extreme Ultraviolet Lithography （ EUVL ） .The analysis of error for this new WRS and calibration of the system error is very important for realizing a more accurate test of wavefront aberration .Based on the analysis of various errors , we study the calibration algorithm in detail , and obtain the tolerance of several WRS important components including that the angle tolerance of rotation stage is 0.5°and the deviation factor is 0.5%when rotation is away optical axis .