椭圆偏振光谱测量技术通过测量线偏振光经材料表面反射后光的相对振幅与相位改变量计算得到椭偏参数, 再通过椭偏参数的拟合获取样品光学性质。由于其具有非接触、高灵敏度、非破坏性等优势, 广泛应用于物理、化学、材料科学和微电子等方面, 是一种不可或缺的光学测量手段。本文首先简要回顾了该技术的发展历程, 接着阐述了传统椭偏仪的基本原理, 按照测量原理的不同可将椭偏仪分为消光式和光度式。随后, 本文简单介绍了一些常用椭偏仪的基本架构、测量原理和相关应用, 并比较了他们的优缺点, 重点展示了复旦大学研制的双重傅立叶变换红外椭偏光谱系统。然后按照椭偏参数处理的基本步骤: 测量、建模与拟合3个方面, 阐述了其过程, 详细剖析了参数拟合所使用的各种光学色散模型, 同时通过应用实例介绍了各色散模型的应用情况。最后, 对未来椭偏技术的发展方向进行了展望。

Spectroscopic ellipsometry is used to measure the relative amplitude and phase change of linearly polarized light reflected by a material surface, so as to obtain the ellipsometric parameters. The optical properties of a material can be deduced by fitting these parameters. This technique is advantageous for being non-contact, highly sensitive, non-destructive, so it is widely used in physics, chemistry, materials science and microelectronics, etc, being an indispensable optical measurement method. This article first introduces the development history of the technology, and then presents the basic principle of the traditional ellipsometer. According to different measurement principles, ellipsometers can be divided into two types: extinction and photometric. The basic structure, measurement principle and related application of these two different types of ellipsometer are briefly clarified. After comparing these various ellipsometers, their advantages and disadvantages are introduced. At this point, a double Fourier transform infrared ellipsometry system developed by Fudan University is highlighted. Then, according to the basic steps of ellipsometric parameter manipulation, a measurement, modeling and fitting process is introduced. The equations of various optical dispersion models used for parameter fitting are introduced in detail and application examples are illustrated. Finally, the future development direction of spectroscopic ellipsometry is proposed.