误差补偿技术在相位偏移干涉测量中的应用

在研究泰曼—格林相位偏移干涉仪测量原理基础上，分析了位移驱动器移相误差对五幅移相计算结果的影响，一阶线性误差和二阶非线性误差是相位偏移干涉测量技术中产生相位误差的主要因素；提出了五幅算法移相误差补偿技术，该方法直接从相位偏移干涉图中计算移相过程中存在的一阶及二阶移相误差，对五幅算法结果进行误差修正；采用玻璃平晶为测试对象，建立了泰曼一格林干涉仪移相误差补偿原理试验系统。试验结果表明在同时存在一阶移相误差及二阶移相误差情况下，采用提出的移相误差补偿方法可以将位移测量精度提高6倍，相当于采用氦氖激光器的倍程干涉仪中位移精度达到1．0nm。

The Application of Error Compensation Technology in Phase Shifting Interferometer with Nanometer Accuracy

On the basis of study on the phase shifting interferometry,this paper analyses the effect of phase-shifting deviation to 5 step algorithm which proves that the one step lineal errors and the two step non-lineal phase shifting deviation are the main contribution to the uncertainty of phase shifting interferometry,puts forward one novel error compensation method for 5-step phase-shifting method which estimates the phase shifting errors according to the measurement data directly and the data results from the five step method are corrected set up the Taymann-Green interferometer for testing the method measures surface of the wafer.The experiments testify this error compensation method can reduced the measurement error from 5.5nm to 1.0nm with the phase-shift deviation of both 10% linear and 1% nonlinear in double pass interferometer with stabilized 632.8nm He-Ne laser.