光刻机投影物镜的像差原位检测新技术

提出了一种新的光刻机投影物镜像差原位检测(AMF)技术。详细分析了该技术利用特殊测试标记检测投影物镜球差、像散、彗差的基本原理,论述了该技术利用对准位置坐标计算像差引起的成像位置偏移量的方法。实验结果表明AMF技术可实现球差、彗差、像散等像差参量的精确测量。AMF技术考虑了光刻胶等工艺因素对像差引起的成像位置偏移量的影响,有效避免了目前基于硅片曝光方式的彗差原位检测技术对离焦量、像面倾斜等像质参量限制的依赖。

New Technique for Aberration In-Situ Measurement of a Lithographic Projection System

A new technique for measuring the aberrations of a lithographic projection system in situ is proposed,in which the basic theory used to measure the spherical aberration,coma and astigmatism of the projection system with special measurement mark is analyzed in detail,and the method to calculated the image displacement caused by aberration through aligned position coordinate is presented.Through experiments,the aberration parameters,such as spherical aberration,coma and astigmatism of the projection system are obtained with high accuracy by the technique.Taking into account of the influences of process factors,e.g.resist process,on the image displacement induced by aberration,the new technique avoids the dependence of coma in-situ measurement based on wafer exposure on the image parameters,such as defocus and image tilt.