基于白光光谱干涉技术的薄膜测量方法研究

发布时间：2018-04-28 17:55

本文选题：薄膜测量 + 白光干涉　；参考：《天津大学》2014年硕士论文

【摘要】：薄膜作为一种特殊的结构,具有与块状材料不同的独特性能,在光学、信息、生物、航天等领域得到广泛应用。薄膜的各种特性直接决定着其能否正常工作,因此对薄膜的检测越发重要。白光光谱干涉技术作为一种光学测试方法,具有非接触、高精度等特点,被广泛应用于薄膜特性检测领域。该方法不仅能够测量薄膜厚度、折射率等信息,而且也能测量相位特性,具有其独特的优势。本课题围绕白光光谱干涉技术展开,研究基于该技术的薄膜特性检测,在分析相关理论的基础上搭建测试系统,实现薄膜特性检测。论文的主要工作如下:1.系统论述了薄膜的发展和应用,对目前常用的薄膜测试方法进行总结归纳,并详细阐述了白光光谱干涉测试技术的发展现状。2.分析了白光光谱干涉技术原理。从干涉原理、部分相干光理论和薄膜结构反射特性三个方面分析了该技术的理论基础,为后续工作奠定基础。3.研究了几种常用相位提取算法,从求解精度、测量范围、运算时间、抗噪能力、引入误差形式等方面进行比较,选择时间相移法作为本系统的相位提取算法。4.阐述了最优化理论,针对局部算法,提出了两种初值确定方法,基于非线性相位提取初值和基于反射率提取初值,两种方法均能提取合适的初值用于优化计算;针对全局算法,设计了模拟退火法和遗传算法用于测量薄膜特性参数,两种方法均能在不需初值的情况下取得较精确的结果。从时间、精度等方面对几种方法进行分析,结果表明局部算法相比全局算法能够在更短的时间内得到精度更高的结果;但全局算法不需要初值,并且能够同时测量膜厚和折射率。5.详细分析了影响系统测量精度的因素,包括光源、分光棱镜、光谱仪等,给出了等效厚度的变化规律,提出了利用等效波长修正系统误差的方法。利用高精度压电扫描器对系统精度进行了测试,结果表明系统具有纳米级测量重复性与复现性。通过测量NIST认证的标准薄膜样品,验证了系统和方法的可行性。
[Abstract]:As a special structure, thin film has the unique properties different from the bulk material. It has been widely used in the fields of optics, information, biology, space and other fields. The various properties of the film directly determine whether it can work properly. Therefore, the detection of the film is more important. White light spectral interferometry as an optical testing method has no connection. Touch, high precision and so on, it is widely used in the field of film characteristic detection. This method not only can measure the thickness of the film, the refractive index and the other information, but also can measure the phase characteristics. It has its unique advantages. This topic focuses on the white light spectral interference technique, and studies the film characteristics detection based on this technology, and analyzes the basis of the related theory. The main work of this paper is as follows: 1. systematically discusses the development and application of thin film, summarizes the commonly used film testing methods, and expounds the development status of white light spectral interferometry technology in detail.2. analysis the principle of white light spectral interferometry. The theoretical basis of this technology is analyzed by three aspects of the theory of partially coherent light and the reflection characteristics of the film structure. Several common phase extraction algorithms are studied for the follow-up work and.3. is studied. The time phase shift method is selected as the time phase shift method to compare the accuracy, the measurement range, the operation time, the noise resistance and the error form. The phase extraction algorithm.4. describes the optimization theory. According to the local algorithm, two initial value determination methods are proposed. Based on the nonlinear phase extraction initial value and the initial value based on the reflectivity extraction, the two methods can extract the appropriate initial value for optimization calculation. The two methods can obtain more accurate results without the initial value. The results show that the local algorithm can get more accurate results in a shorter time than the global algorithm, but the global algorithm does not need the initial value, and can measure the thickness of the film at the same time. The refractive index.5. analyses the factors affecting the measurement accuracy of the system in detail, including the light source, the optical prism, the spectrometer and so on. The variation law of the equivalent thickness is given. The method of correcting the system error by the equivalent wavelength is proposed. The precision of the system is tested by the high-precision piezoelectric scanner. The results show that the system has the nanometer scale measurement repetition. Sex and reproducibility. The feasibility of the system and method is verified by measuring NIST certified standard film samples.

【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：O484.5

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