Smile distortion caused by aberration of the optical system is the key factor that affects the spectral calibration of a white-light spectral interferometer. To improve the accuracy of surface metrology, this paper proposes a novel calibration approach based on a line-by-line method. An acousto-optic tunable filter (AOTF) is adopted for the wavelength scanning process during calibration. By fitting sufficient calibration data, a more accurate relationship between wavelength and pixel position can be obtained. The simulation results show that the accuracy of surface metrology has different sensitivities to the coefficients of the calibration equation, and that the effect of smile distortion becomes more severe as the optical path difference increases. The presence of smile distortion is confirmed in the calibration experiment of a home-built white-light spectral interferometer. Subsequently, a silicon wafer and a standard step of 1.806 ± 0.011 μ m are tested using the calib...

中文翻译：

---

使用逐行光谱校准方法提高白光光谱干涉仪的精度

由光学系统像差引起的笑容失真是影响白光光谱干涉仪光谱校准的关键因素。为了提高表面计量的准确性，本文提出了一种基于逐行方法的新型标定方法。校准期间，波长扫描过程采用声光可调滤光片（AOTF）。通过拟合足够的校准数据，可以获得波长和像素位置之间更精确的关系。仿真结果表明，表面度量的精度对校准方程的系数具有不同的敏感性，并且随着光程差的增加，微笑失真的影响变得更加严重。在自制的白光光谱干涉仪的校准实验中确认了微笑失真的存在。随后，使用校准仪测试硅片和标准步长1.806±0.011μm。