成像椭偏测量技术研究
文献类型：学位论文
| 作者 | 胡仕玉 |
| 学位类别 | 硕士 |
| 答辩日期 | 2015 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 曾爱军 |
| 关键词 | 成像椭偏测量 椭偏参量 装调与标定 薄膜参数 缺陷检测 |
| 其他题名 | Study on imaging ellisometry |
| 中文摘要 | 薄膜材料和薄膜技术研究在材料研究领域中越来越重要，确定薄膜参数对于薄膜特性研究具有重要意义。随着纳米技术的发展和集成电路的特征尺寸的缩小，许多实际应用对薄膜参数测量方法提出了新的要求，比如快速、高精度、大面积区域检测和实时在线检测等，成像椭偏测量技术不仅具有上述优点，还能够测量超薄薄膜和多层薄膜。本文主要围绕成像椭偏测量技术的原理、算法和成像椭偏仪的研制、应用等方面展开研究，主要包括以下几个方面： 1.概述了成像椭偏测量技术的概念及其在薄膜参数测量中的优势与应用，描述了成像椭偏测量技术的发展历程和国内外现状。详细介绍了成像椭偏测量技术的测量原理和处理算法，具体分析了椭偏参量与薄膜参数的关系。 2.设计了成像椭偏仪的光学系统、硬件电路、处理算法和应用软件。将PCSA（起偏器—补偿器—样品—检偏器）结构的消光式椭偏仪与成像系统相结合构成成像椭偏仪的光学系统，确定了光学器件的选型和特性。硬件控制系统主要由伺服电机、步进电机、驱动器、光栅尺和控制卡组成。研究了光度测量法与消光测量法相结合的混合处理算法，可以缩短测量时间同时提高精度.利用VC++编写了软件的控制模块、图像处理模块和数据分析模块。 3.研究了成像椭偏仪的装调和标定方法。利用以一对偏振分光剪切平板为核心的移相剪切干涉仪检测光源的准直性。移相剪切干涉仪由激光器、一对偏振分光剪切平板、偏振移相器和图像传感器组成，仅需要将偏振分光剪切平板放置在合适的位置，光程差可获得补偿，实现了等光程共光路测量。实验中，基于该方法的测量结果与仿真结果一致，很好地验证了该方法的有效性。完成了激光器、扩束镜和远心透镜的装调。给出了一种成像椭偏仪的系统参数校准方法，校准的系统参数包含左右光栅尺原点、起偏器和检偏器的偏振方向和补偿器的快轴，校准完成后，无需调整系统部件即可直接测量。通过测量参考样品、多入射角测量样品和不同空间分辨率分析样品来标定成像椭偏仪的特性。 4.开展了成像椭偏测量技术的应用研究。提出了一种基于椭偏成像光路和表面等离子体共振效应的金属薄膜参数测量方法，在椭偏成像光路中采用P偏振光在金属薄膜与空气界面产生表面等离子体共振效应，利用不产生表面等离子体共振效应的S偏振光消除背景光的影响，得到表面等离子体共振吸收环垂直方向的归一化反射率曲线，数值拟合获得待测金属薄膜的薄膜参数。实验中，基于该方法的测量结果与标准椭偏仪的测量结果基本一致，很好地验证了该方法的有效性。研究了基于成像椭偏测量原理的薄膜缺陷检测方法，根据成像椭偏测量原理设计了两组对比实验并对四个实验样品进行测量，通过分析四个样品的椭偏参量的三维分布图和图像传感器采集的消光图像，可以快速分辨薄膜缺陷的位置、大小和形状，该方法可用于薄膜样品的较大面积区域检测和实时在线检测。 |
| 英文摘要 | Thin film materials and technology play a more important role in the research of materials and measurement of thin film parameters is of great significance for research of thin film properties. With the development of nanotechnology and scaling of feature size of integrated circuit, new requirements for measurement of film parameters in many applications are proposed, such as high speed, high precision, detecting samples of large area and real-time online measurement and so on. Not only the above conditions are satisfied, the imaging ellipsometric technique is also capable of testing ultrathin film and multilayer film. In this paper, the work focusing on the principle and algorithm of imaging ellipsometry, the development and applications of imaging ellipsometer mainly includes the following aspects. 1. Summarize the concept of imaging ellipsometry, the advantages and applications in the measurement of thin film parameters. The development history and domestic and international situation of imaging ellipsometry are described. Introduce the principle and processing algorithm of imaging ellipsometer and analyze the relationship between the ellipsometric parameters and the film parameters in details. 2. Design the optical systems, hardware circuit, processing algorithm and application software of the imaging ellipsometer. Devise the optical systems of imaging ellipsometer with the combination of null ellipsometer with the configuration of PCSA (polarizer-compensator-sample-analyzer) and imaging system. And confirm the optical element selection and characteristics. Hardware control system is composed of servo motor, stepping motor, motor driver, grating ruler and control card. Study a combinatorial processing algorithm by combining the photometric method and null method, which shortens the measure time and improve the precision. Compile the control module, imaging processing module and data processing module of the application software with VC++. 3. Study the method of alignment and calibration of imaging ellipsometer. Test the collimation of laser with a polarization phase shifting lateral shearing interferometer based on a pair of polarization beam splitting plates at the core. This polarization phase shifting lateral shearing interferometer is composed of a laser, a pair of polarization beam splitting plates (PBSP), a polarization phase shifter and an image sensor. With a pair of polarization beam splitting plates positioned in appropriate spatial positions, optical path difference compensation is achieved, which allows for the implement of Aplanatic and common-path measuring. The experimental result with this method is coincident with simulation result, which verifies the validity of this measurement method. Complete the alignment of the laser, beam expander and telecentric lens. A calibration method of system parameter of imaging ellisometer is proposed, which contains the origin of left and right grating ruler, the transmission axis of polarizer and analyzer and the fast axis of compensator. When the calibration is finished, it’s not necessary to adjust system parts and imaging ellipsometer can be used for measurement immediately. Calibrate the performance of imaging ellipsometer with reference samples, multiple-angle ellipsometry and multiple spatial resolutions. 4. Study the application of imaging ellipsometry. A measurement method of film parameters of metal based on imaging ellipsometry and surface-plasmon resonance is presented. P polarized light is applied to generate surface-plasmon resonance effect at the interface of metal film and air in layout of imaging ellipsometry. The influence of back light is avoided by S polarized light which can’t lead to surface-plasmon resonance effect. Then the normalized reflectance profile along the perpendicular direction of absorption ring of surface-plasmon resonance is obtained. We measure metal film parameters by numerical fitting the reflectance profile along long axis of the elliptical fringe. The experimental result with this method is coincident with that of standard ellipsometer, which verifies the validity of this measurement method. A new method for detection of defect in thin film with imaging ellipsometric technique is studied. Two groups of contrast experiments based on the principle of imaging ellipsometric technique are designed, and the four experimental samples are measured. Through the analysis of the distribution of the ellipsometric parameters and the null image from image sensor, it can quickly determine the location, the size and the shape of surface defect in thin film. And it possesses advantages of testing samples of large areas and real-time online measurement. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/16947]  |
| 专题 | 上海光学精密机械研究所_学位论文 |
| 推荐引用方式 GB/T 7714 | 胡仕玉. 成像椭偏测量技术研究[D]. 中国科学院上海光学精密机械研究所. 2015. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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