计算全息图案位置误差致波前误差的标定方法  

Calibration Method of Pattern Place Error-Induced Wavefront Distortion with Complex-Phase Computer-Generated Holograms

作　　者：张海涛 徐乐[2] 谢常青[1,3] Zhang Haitao;Xu Le;Xie Changqing(Key Laboratory of Microelectronic Devices&Integrated Technology,Institute of Microelectronics of the Chinese Academy of Sciences,Beijing 100029,China;State Key Laboratory of Applied Optics,Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,Jilin,China;School of Integrated Circuits,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院微电子研究所微电子器件与集成技术重点实验室,北京100029 [2]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,吉林长春130033 [3]中国科学院大学集成电路学院,北京100049

出　　处：《光学学报》2023年第8期393-400,共8页Acta Optica Sinica

基　　金：应用光学国家重点实验室开放基金(SKLAO2021001A05)。

摘　　要：通过对计算全息图检测非球面的误差进行分析,提出了一种用于计算全息图检测非球面过程中图案位置误差引入的波前误差的标定方法。该方法先设计检测过程中所需要的辅助波前和检测波前在计算全息基板上所对应的相位分布,再通过光场叠加的方式得到复合相位。辅助波前用于计算实际位置与设计位置的偏差,进而计算出位置畸变引起的检测误差,并将其从系统中消除。检测波前用于得到与非球面匹配的波前,进而对非球面面形进行检测,并提出了图案位置误差引入的非球面波前差的计算方法。为评估该方法的可行性,将复合相位所对应的计算全息图导入衍射计算软件中进行仿真,同时得到了平面、球面和非球面各个级次的衍射光斑,证明了该方法的正确性。Objective The pattern place error is one of the main factors that influence the accuracy in the metrology of aspheric surfaces based on computer-generated holograms(CGHs).This error is difficult to calibrate with traditional methods.Hence,a new method for calibrating the wavefront distortion introduced by the pattern place error on the basis of the complex phase is proposed.According to the design and manufacturing process of CGHs,the main errors consist of the substrate error,pattern processing error,and imaging distortion.The substrate error includes the surface figure error,surface wedge angle error,and refractive index inhomogeneity of the substrate material.The pattern processing error includes the pattern place error,duty cycle error,and etching depth error.The imaging distortion mainly affects the mapping error of the imaging place,which should be carefully considered when the measurement data is used to process the surface.Of these errors,the substrate error can be well calibrated and compensated during data processing,and the imaging distortion can be corrected by means of image distortion processing.However,there is no way to calibrate the pattern processing error,especially the error caused by the pattern place error.The wavefront distortion induced by the pattern place error maintains a level around the sub-nanometer.Therefore,if the impact of this error can be eliminated,the measurement accuracy can be better than 0.1 nm(root mean square,RMS)theoretically.To this end,a calibration method using the complex-phase CGH which generates the auxiliary wavefront and test wavefront simultaneously is proposed in this paper.Methods The CGH which can generate multiple wavefronts simultaneously is designed in this paper.The wavefronts include the plane wavefront along the x direction,the plane wavefront along the y direction,the spherical wavefront,and the aspherical wavefront.The plane wavefront and spherical wavefront are auxiliary wavefronts,and the aspherical wavefront is the test wavefront which can match th

关 键 词：光学设计 非球面 复合相位 计算全息 图案位置误差 绝对检测 

分 类 号：O436[机械工程—光学工程]