光刻系统中工作台位移的长行程高精度双色差分干涉测量方法研究

Lithography is the key equipment for large-scale integrated circuit and scanning holographic grating fabrication. It has high motion performance requirements for the stage. To meet these extreme sports needs, a high-precision displacement measurement system is necessary. The two-color heterodyne laser interferometry has the advantages of wide range, high resolution and fast measurement speed. It also makes up for the disadvantage of the heterodyne laser interferometer which is greatly influenced by the environment. It is an ideal scheme for the displacement.measurement of the high-precision stage.. The research of dichroic differential interferometry mainly has the following basic problems to be solved: firstly, the mechanism of the influence of monochrome measurement system errors on the accuracy of dichroic measurement is not clear; secondly, the technical parameters of dichroic differential interferometry model are not perfect; thirdly, the technical methods of measurement error compensation are not applicable. Through the study of the above problems, a general two-color differential interferometric measurement model is established, which is related to the optical structure parameters, laser wavelength, atmospheric environment and other parameters, and a mathematical model of random measurement error compensation is established. Finally, nanometer-scale accuracy measurement is realized.

光刻机是大规模集成电路和扫描全息光栅制作的关键设备，对工作台具有很高的运动性能需求，为满足这些极端的运动需求，必须配套高精度的位移测量系统。双色外差干涉测量法具有外差激光干涉仪量程大、分辨率高和测量速度快的优点，同时弥补了外差激光干涉仪受环境影响大的缺点，是高精度工作台位移测量的理想方案。. 双色差分干涉测量方法的研究主要存在以下需要解决的基础性问题：一是单色测量系统误差对双色测量精度影响的产生机理不明确；二是双色差分干涉测量模型的技术参数不健全；三是测量误差补偿技术方法不适用。本课题通过对以上问题的研究，建立光学结构参数与激光波长、大气环境等参数内在联系的通用双色差分干涉测量模型，并建立随机测量误差补偿数学模型，最终实现米级尺度上纳米精度的测量。

光刻机是大规模集成电路和扫描全息光栅制作的关键设备，对工作台具有很高的运动性能需求，为满足这些极端的运动需求，必须配套高精度的位移测量系统。双色外差干涉测量法具有外差激光干涉仪量程大、分辨率高和测量速度快的优点，同时弥补了外差激光干涉仪受环境影响大的缺点，是高精度工作台位移测量的理想方案。本课题的主要研究内容包括：一是设计传统双色测量模型误差溯源及两种波长的外差干涉测量系统；二是研究双色差分干涉测量波长相关误差综合补偿方法；三是研究双色外差激光干涉测量波长无关误差补偿方法。通过本课题的研究，研制了两套适用于不同波长的外差激光干涉测量系统；建立了单色外差激光干涉测量与气压、温度、湿度等环境参数之间内在联系的数学模型和双色差分干涉测量波长相关误差综合补偿模型；提出了波长无关误差补偿方法，建立了随机测量误差补偿数学模型，最终实现了米级尺度上纳米精度的测量。