纳米厚度薄膜外差椭偏测量技术的研究  

Study of heterodyne ellipsometry for nanometer film measurement

作　　者：邓元龙[1] 姚建铨[1] 阮双琛[2] 孙秀泉[2] 王鹏[1] 

机构地区：[1]天津大学精密仪器学院激光及光电子研究所,天津300072 [2]深圳大学工程技术学院,深圳518060

出　　处：《光学技术》2005年第3期391-393,共3页Optical Technique

基　　金：广东省自然科学基金(031809);广东高校自然科学研究项目(Z02062);深圳大学校级科研项目

摘　　要：结合激光外差干涉法和透射式椭偏测量原理,研究了一种快速、高精度测量纳米厚度薄膜光学参数的方法。计算并分析了复灵敏度因子随薄膜参数和入射角度的变化规律、椭偏参数的选择及容许测量误差。两个声光调制器产生20kHz的拍频,采用简单的直接比相方法即可获得优于0.1°的相位分辨率,而且测量系统中没有使用任何波片和运动部件,抗干扰能力强且测量过程完全自动化,适用于工业现场在线连续测量。实验数据和理论分析表明,此方法可以达到亚纳米级测量精度。Combining optical heterodyne interferometry with transmitted ellipsometry, a new precision method with high speed was applied to the measurement of nanometer film. The relationships between accuracy of ellipsometric parameters and measurement results were discussed in terms of numeric analysis of coefficient of complex sensitivity. Two acoustooptic modulators were used to generate 20 kHz beat frequency, so the resolution of phase measurement reached 0.1°C by simply direct-phase-comparison method, and no wave plates and moving mechanism appeared in the system. With automation process and high anti-interference performance, this method is applicable to continuous measurements on the industrial spot. The possibility up to sub-nanometer accuracy was demonstrated by the experimental results.

关 键 词：光学测量 薄膜 外差干涉法 椭偏测量术 声光调制器 纳米精度 

分 类 号：TH744.3[机械工程—光学工程]