大偏离度非球面检测畸变校正方法  

Distortion correcting method when testing large-departure asphere

作　　者：高松涛[1] 武东城 苗二龙[1] 

机构地区：[1]中国科学院长春光学精密机械与物理研究所应用光学国家重点实验室超精密光学工程研究中心,吉林长春130033

出　　处：《中国光学》2017年第3期383-390,共8页Chinese Optics

基　　金：国家科技重大专项资助项目(No.2009ZX02205)~~

摘　　要：在高数值孔径(NA)投影光刻物镜中,随着数值孔径的增加,非球面的偏离度越来越大。对这种大偏离度非球面进行亚纳米量级的检测,一直是光学检测的一大难题。本文首先对一偏离度超过500μm的偶次高次非球面进行了计算全息图(Computer-Generated Hologram,CGH)设计,设计出了满足高精度面形检测和刻蚀加工要求的CGH。然后,针对此设计方案,定量分析了CGH的成像畸变及畸变对像差分析的影响。分析结果表明,不同径向位置的成像倍率偏差(畸变)最大达到了2.7∶1,并且由于畸变的存在,低阶像差衍生出了明显的高阶像差。最后,针对用CGH检测大偏离度非球面时出现的成像畸变,提出了采用光线追迹与最小二乘法相结合的成像畸变的校正方法,并通过实验验证了此方法的准确性。实验结果表明,畸变校正之后相对剩余残差小于0.2%,可以满足高精度非球面检测加工的要求。With the projection objective. For an asphere with increase in numerical aperture, the aspheric It is a problem to test the large-departure asp aspheric departure exceeding 500 micrometers departure is also increasing in the high-NA here in nanometers in the optical metrology. , firstly, we design a CGH to satisfy the de- mands of high precise testing and etching fabrication. Secondly, the imaging distortion and the effect of distortion on aberration are analyzed quantitatively. The analysis resuhs show that the maximum magnification deviation is 2. 7：1 for the different radial positions, and the low order aberrations will generate high order aberrations obviously. Lastly, we propose the ray trace and least square method to correct the imaging distortion when testing large-departure asphere with CGH, and verify the precision of the method through the experiments. The results show that the relative residue is less than O. 2% after correcting, and the precision will satisfy the demands of high precise optical testing and fabrication.

关 键 词：计算全息图 CGH 畸变 非球面检测 

分 类 号：O436.1[机械工程—光学工程]