薄膜光学参数表征误差处理技术

摘要

针对光度测量数据中难以消除的系统误差对薄膜光学参数表征精度的负面影响,提出一种新型的误差处理技术.选取薄膜光谱系数对折射率和几何厚度的一阶偏导数,对大部分测量入射角满足符号相反或只有其中一个为零的条件的波段,剔除偏导数对全部测量入射角满足符号相同或同时为零条件的奇点波长附近波段,作为反演表征用的光度测量数据采集区域,以最小化光度测量系统误差引起的薄膜光学参数反演表征值相对真实值的偏差大小.通过数值模拟实验,对比研究了该技术对不同偏振光和不同测量入射角范围的适用性及实施技巧,以可复现的数值实验数据和合理的理论解释支持和验证了这种误差处理技术的可靠性.%A technique of errors treatment is presented according to the negative impact of systematic errors, which is hard to eliminate in photometric measurement data, on the characterization accuracy of thin film optical parameters. In order to minimize the characterization deviations of thin film optical parameters from the real values caused by photometric measurement systematic errors, it is advised to select the photometric measurement data used in optical characterization from spectral bands characterized with opposite signs or single zero of first-order spectral coefficient' s partial derivatives with respect to layer thickness and refractive index for most measurement incident angles, and to exclude spectral bands characterized with the same signs or both zeros of spectral coefficient's first-order partial derivatives for all measurement incident angles. The essence of this technique is to minimize the errors transfer effect of measurement data on thin film optical parameters characterization by spectral band selection with first-order partial derivatives analysis. Numerical simulations have been conducted to investigate its applicability to characterization with different polarization lights and the skills in selection of the range of measurement incident angles. The reliability of this technique is supported by replicable numerical experiments and reasonable theoretical explanations