大扫描范围针尖扫描式原子力显微镜
文献类型：学位论文
| 作者 | 杨金涛 |
| 学位类别 | 博士 |
| 答辩日期 | 2007 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 徐文东 |
| 关键词 | 纳米技术 原子力显微镜 大扫描范围 针尖扫描 光点跟踪 光束偏转法 |
| 其他题名 | Scanned-cantilever atomic force microscope with large scanning range |
| 中文摘要 | 纳米科学与技术是现代科学(混沌物理、量子力学、介观物理、分子生物学)和现代技术(计算机技术、微电子和扫描隧道显微镜技术、核分析技术)结合的产物，它的发展推动了与纳米技术相关的许多新兴学科的发展，比如纳米物理学、纳米电子学、纳米材料学、纳米生物学、纳米机械学和纳米测量学等，纳米科技对各个领域的重要影响确定了它在当今以及未来科技发展中的重要地位。以扫描隧道显微镜(STM)和原子力显微镜(AFM)为代表的扫描探针显微镜不仅推动了纳米科技的发展，而且也是现如今纳米科研工作中必不可少的工具。尤其是原子力显微镜，它可以在真空、大气、液体的环境下，对导体和非导体的各种样品进行测试，因而具有更广泛的应用领域。 常见的原子力显微镜多采用样品扫描方式，因为样品尺寸和重量受到传统的管状压电陶瓷扫描器的限制，它只适合小样品的测试。本文提出了大扫描范围针尖扫描式原子力显微镜的设计思想，对其原理和方法进行了系统的研究，在国内率先成功研制了新型大扫描范围针尖扫描式的原子力显微镜，拓展了原子力显微镜的应用范畴。研制的大扫描范围针尖扫描式原子力显微镜样机的扫描范围100um*100um，纵向分辨率1nm左右，横向分辨率2nm左右。 本文在介绍了原子力显微镜的基本原理的基础上，详细分析了与原子力显微镜有关的各个方面的问题，包括：针尖与样品之间的各种相互作用力，微悬臂的制备要求，微悬臂偏转检测光路的原理，原子力显微镜的工作方式和成像模式，力曲线的意义和作用；着重分析了原子力显微镜主体的各种不同组合结构及其优缺点。概述了原子力显微镜的国内外发展现状及存在的主要问题，为研制大扫描范围针尖扫描式原子力显微镜提供了必要的知识准备，并指明了研制的方向。 本文还根据针尖扫描原子力显微镜的原理，讨论了针尖扫描式原子力显微镜的设计关键——光点跟踪的要求；介绍了国外各种针尖扫描式原子力显微镜的实现方式，并分析了优缺点，作为大扫描范围针尖扫描式原子力显微镜设计的参考。 在原子力显微镜的文献研究和针尖扫描式原子力显微镜的在先技术分析的基础上，针对xyz正交移动的平板扫描器带动针尖的情景，提出了针尖扫描式原子力显微镜需要满足的光点跟踪的新方法，并具体设计了相应的光路。大扫描范围针尖扫描式原子力显微镜的光点跟踪的特点是：激光器和四象限光电探测器不跟随扫描器运动，但是微悬臂背面顶端的汇聚光斑能紧密跟随微悬臂在xyz方向移动，而且保证即使没有样品的空扫描状态，四象限光电探测器上的光斑在上下的方向上移动的最小，这种方法不仅满足了光点跟踪的要求，而且对扫描器的负载能力的要求比较小，不会太影响扫描器的共振频率。我们通过matlab模拟计算，证明了这种光点跟踪方法的正确性。我们还分析了检测光路布置对探测的灵敏度的影响，为优化检测光路提供了分析数据。 利用上面的光点跟踪的新方法，研制了新型大扫描范围针尖扫描式的原子力显微镜。它采用xy和z独立的平板扫描器组成可在xyz三个方向上正交运动的组合扫描器，带动针尖在样品表面扫描；一维纳米位移平台带动样品台向针尖逼近；光学显微镜和CCD监视系统与原子力显微镜相结合，通过对样品观测区域的光学成像，为样品观测区域的选择提供参考，而且还有助于原子力显微镜的调节。xy和z独立的平板扫描器都采用反馈技术控制其移动位置，线性好，重复性高，克服了管状压电陶瓷扫描器的缺点。大扫描范围针尖扫描式原子力显微镜的各项性能的测试实验都验证了新型大扫描范围针尖扫描式原子力显微镜具有图像清晰、扫描范围大、重复性好、稳定性高、维护简单的优点。 在此原子力显微镜系统的基础上，试着采用12位的AD/DA卡来代替原子力显微镜的控制系统，编写了简洁的原子力显微镜应用软件，实现了基本的功能，可以控制原子力显微镜工作。实验得到了CD盘基的图像，由于AD/DA卡的分辨率限制，改进的原子力显微镜系统的分辨率不高，但是对于基于AD/DA卡控制系统的原子力显微镜的实验是一个很好的尝试，为改进此针尖扫描式原子力显微镜使其能检测样品的磁畴打下了基础。 |
| 英文摘要 | Nano science and technology derived form the modern science (such as Chaos Physics, Quantum mechanics, Microstructure Physics, Molecular Biology) and technology (such as Computer Technology, Mircoelectronics Technology, Scanning Probe Microscope Technology, Nuclear analytical techniques). Its development facilitates the development of some brand-new science, such as nano-physics, nano-electronics, nano-biology, nano-mechanics and nano-measurements. The far-reaching influence of nano-technology in science fields ensures nano-technology’s important position in development of technology in future. The scanning probe microscope (for example，scanning tunneling microscope and atomic force microscope ) not only impels the development of nano-technology, but also is the indispensable tool in research of nano-technology today. In particular, atomic force microscope (AFM) can test electric or insulative sample in wide ambient such as vacuum, air or liquids, so AFM has a broader application. Most of the AFMs scan sample under a stationary cantilever. These AFMs only can test small samples, because the size and weight of the sample is restricted by the size and resonance frequency of the tube piezoceramics scanner. This thesis puts forward a design method about scanned-cantilever atomic force microscope with large scanning range, analyses and researches the theory and method of the scanned-cantilever AFM. The scanned-cantilever atomic force microscope with large scanning range is a pioneer in China; its invention will develop the application field of the AFM. The scanned-cantilever AFM can realize max 100um*100um scanning area, and the error in z direction is 1nm, the error in xy direction is about 2nm. On the basis of the introduction of the theory of AFM, this thesis detailedly analyses some problems about AFM. These problems include: the interactional force which between the tip and sample, the requires of making cantilever, the theory of “optical lever”, the working mode and imaging mode of the AFM, the significance of the force-distance curve. In addition, the thesis detailedly discusses all kinds of configuration of the AFM and corresponding characteristics. The research of the developmental status of the AFM and the existent problem of the AFM offeres the important direction and theory for developing of the scanned-cantilever atomic force microscope with large scanning range. This thesis discusses the key of design of the scanned-cantilever AFM, presents the concept of laser spot tracking, introduces some design methods of the scanned-cantilever AFM which presented in foreign literature, analyses the advantage and disadvantage of these design methods. These works offer the important reference for the design of the scanned-cantilever atomic force microscope with large scanning range. On the basis of the theoretical researches and the analysises about the design methods of the scanned-cantilever AFM which presented in foreign literature, we present a new design of laser spot tracking that can be applied to scanned-cantilever atomic force microscope, designed the optical lever system which can measure the deflection of the cantilever. The significant characteristics of the scanned-cantilever AFM include: (i) the laser and the PSD are stationary, not track the motion of the scanner. (ii) the focused spot on the back of the cantilever can track the scanning motion of the scanner. (iii) the convergent light spot on the PSD of the optical lever detection system can keep relatively stationary with the PSD or move very little when the AFM scans without samples. The design of the laser spot tracking satisfys requires of the scanned-cantilever AFM, does not request the high load ability of the scanner, so it has few influence to the resonance frequency of the scanner. By the simulation in matlab, we proved the feasibility of the laser spot tracking. We also analysed how the size of the convergent light spot on PSD influences the sensitiveness of the PSD. Using the method of laser spot tracking, we designed a scanned-cantilever AFM with large scanning range. It uses the separate flexure x-y scanner and z scanner instead of the conventional piezoelectric tube scanner scanning the tip, uses a linear positioning stages moving to the tip with sample. Further more, it includes an optical microscope and a detection system. It is helpful for selecting the area of sample in which we interested and operating of AFM. According to the experimental results, it is proved that the scanned-cantilever AFM with large scanning range has many advantages. These include high resolution, large scanning range, high stability and good repeatability. On the basis of the scanned-cantilever AFM with large scanning range, we developed the control system which is based upon 12 bit AD/DA card, programmed the software of these system. By this control system and the software, we achieved the AFM image of CD-R substrate. The meliorative AFM control system and the software can be used to test the distribution of the magnetic domain on samples. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/15556]  |
| 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 | 杨金涛. 大扫描范围针尖扫描式原子力显微镜[D]. 中国科学院上海光学精密机械研究所. 2007. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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