原子力显微镜发展近况及其应用

扫描隧道显微镜(简称STM)和原子力显微镜(简称AFM),它们也可统称为扫描探针显微镜(简称SPM)。原子力显微镜(AFM) 是近十几年来表面成像技术中最重要的进展之一。与扫描电子显微镜相比,它具有较高的分辨率。本文将讨论原子力显微镜的工作原理、原子力显微镜的发展概况和应用。     

复合型超精密表面形貌测量仪

研制了基于同一显微镜基体实现原子力探针扫描测量与非接触光学测量两种功能的复合型超精密表面形貌测量仪.分析了基于白光显微干涉原子力探针的测量方法、探针微悬臂变形量与白光干涉条纹移动量的关系以及探针微悬臂测量非线性误差的修正方法,和通过融合垂直扫描系统的位移量和悬臂梁变形量得到了原子力探针的工作方式.研制了三维精密位移系统...     

基于原子力显微的多模式扫描探针显微镜

扫描探针显微镜是目前世界上分辨率最高的显微镜之一,也是纳米技术研究的主要工具。本文在分析原子力显微镜工作原理的基础上,探讨多模式扫描探针显微镜的相关功能,并对扫描探针显微镜的发展前景进行展望。     

轻敲式扫描探针显微镜

介绍了扫描探针显微镜的发展与分类，对原子力显微镜的三种工作模式的优劣作了比较；重点叙述了轻敲式原子力显微镜的工作原理；引出了轻敲式原子力显微镜应用的一种新技术－相位成像技术，最后简单介绍了由北京市中科机电设备公司于2001年9月推出的Nspm-6800型扫描探针显微镜。     

原子力显微镜管式扫描器运动学建模与误差分析

针对样本扫描模式原子力显微镜,对其管式扫描器-样本-探针系统进行了运动学分析,建立了该系统的运动学模型,该模型表明:对于给定原子力显微镜扫描器,样本上与探针接触点的横向和纵向位移取决于探针尖端相对于扫描管轴心的偏置量、所加电压(或名义扫描范围)及样本厚度。据此模型,对由于弯曲运动模式所产生的两种重要误差—交叉耦合误差及扫描范围误差进行了定量分析,分析表明:扫描范围误差主要受样本厚度及名义扫描范围影响,而Z向交叉耦合误差主要受探针偏置量及名义扫描范围影响,实验验证了所建立的运动学模型和误差计算公式的正确性;另外,还提出了相应的减小误差的方法。     

用于并行SPM的图像合成技术研究

介绍一种针对并行扫描探针显微镜系统的图像合成算法。利用单探针原子力显微镜(AFM)系统模拟多探针扫描探针显微镜(SPM)并行扫描的图像特征。在图像处理上,将中值滤波器及各种边缘检测算法与成像系统集成在一起,以提高成像质量;同时,依靠原理简单并易于实现的标准化协方差相关法实现相邻探针扫描图像的拼接,采用加权合成算法进行图像的自然融合。实验证明,该算法高效、高精度,合成后的图像与原图相似度达到96%,能够满足并行SPM系统的成像要求。     

散射型近场扫描光学显微镜的探针振动参数优化研究

基于原子力显微镜平台设计了可见-近红外波段的散射型近场扫描光学显微镜,通过理论模型计算和实验测量,分析了散射探针振动的调制振幅和扫描反馈幅值对近场信号的影响。研究表明:与探针针尖尺寸相近的调制振幅有利于抑制背景散射噪声及优化近场信号的信噪比;当探针扫描反馈幅值与自由空间调制振幅之比大于90%时,可基本消除探针扫描过程中非简谐振动对近场成像测量的影响。     

开放式多功能扫描探针显微镜系统

开放式多功能扫描探针显微镜、集成扫描隧道显微镜、原子力显微镜、横向力显微镜和静电力显微镜．具有接触、半接触和非接触工作模式，可进行作用力、电流、电位、光能量等参数的高度局域综合测量,具有极高的开放性和可扩展性，支持用户进行二次开发。     

运用碳纳米管原子力显微镜针尖减小长程力作用的研究

减小探针和样品表面之间的长程宏观力是原子力显微镜获得高分辨率成像的关键。首先通过理论分析得出影响长程力的主要因素是探针的几何形状和尺寸。然后分别运用几何形状和尺寸不同的原子力显微镜的传统Si针尖和碳纳米管针尖对样品进行扫描试验研究,结果显示碳纳米管针尖较传统针尖获得了高分辨率的图像。这一结果表明,碳纳米管针尖减小了成像中宏观长程作用力的影响,是理想的原子力显微镜针尖。     

行业信息与动态

多功能扫描探针见微镜中国地质大学（北京）和中国科学院化学所共同研制的多功能扫描探针显微镜，不久前通过了地矿部鉴定。专家们认为，该仪器在高科技检测，尤其是在纳米技术领域有重要的应用价值。多功能扫描探针显微镜是一种具有扫描隧道显微镜、原子力显微镜、侧向力显微镜等多种模式与功能的集激光检测技术、微弱信号技术、精密机械加工及先进的计算机软件硬件技术于一身的高科技产品。其主要技术指标达到国际同类仪器先进水平。（摘自《中国科学报》）CCD电视天文望远镜江西凤凰光学仪器（集团）有限公司东和公司不久前研制成功CC…     

Refined tip preparation by electrochemical etching and ultrahigh vacuum treatment to obtain atomically sharp tips for scanning tunneling microscope and atomic force microscope

A modification of the common electrochemical etching setup is presented. The described method reproducibly yields sharp tungsten tips for usage in the scanning tunneling microscope and tuning fork atomic force microscope. In situ treatment under ultrahigh vacuum (p ≤10(-10) mbar) conditions for cleaning and fine sharpening with minimal blunting is described. The structure of the microscopic apex of these tips is atomically resolved with field ion microscopy and cross checked with field emission.     

生物分子LB膜表面结构与物化性质的原子力显微镜分析

LB膜以其广泛的应用价值而备受关注,而其各种性质的表征是推动其应用的源动力,原子力显微镜以其优秀的时空分辨能力、力学操纵能力而在众多表面表征技术中显得尤为突出。文章在详细介绍原子力显微镜基本探测原理的基础上,全面总结了原子力显微镜技术在LB膜参量,如表面精细结构、静电荷分布、磁畴分布、膜分子间相互作用等分析中的应用,并探讨了该技术在膜表面表征中存在的技术问题,对膜参量表征技术的发展和应用前景进行了展望。     

Atomic force microscope imaging and force measurements at electrified and actively corroding interfaces: challenges and novel cell design

We report the design of an improved electrochemical cell for atomic force microscope measurements in corrosive electrochemical environments. Our design improvements are guided by experimental requirements for studying corrosive reactions such as selective dissolution, dealloying, pitting corrosion, and∕or surface and interface forces at electrified interfaces. Our aim is to examine some of the limitations of typical electrochemical scanning probe microscopy (SPM) experiments and in particular to outline precautions and cell-design elements, which must necessarily be taken into account in order to obtain reliable experimental results. In particular, we discuss electrochemical requirements for typical electrochemical SPM experiments and introduce novel design features to avoid common issues such as crevice formations; we discuss the choice of electrodes and contaminations from ions of reference electrodes. We optimize the cell geometry and introduce standard samples for electrochemical AFM experiments. We have tested the novel design by performing force-distance spectroscopy as a function of the applied electrochemical potential between a bare gold electrode surface and a SAM-coated AFM tip. Topography imaging was tested by studying the well-known dealloying process of a Cu(3)Au(111) surface up to the critical potential. Our design improvements should be equally applicable to in situ electrochemical scanning tunneling microscope cells.     

Surface modification of an organosilane self-assembled monolayer on silicon substrates using atomic force microscopy: scanning probe electrochemistry toward nanolithography

Organosilane self-assembled monolayers (SAMs) have been applied to resist materials for nanolithography based on scanning probe microscopy. An organosilane SAM was prepared on Si substrates from a precursor, that is octadecyltrimethoxysilane. Using an atomic force microscope with a conductive probe, current was injected from the probe into the SAM-covered Si substrate so that the SAM was locally degraded at the probe-contacting point. Nanoscale patterns drawn on the SAM was clearly imaged by lateral force microscopy. The patterning could be conducted in air while, in vacuum at the order of 10(-6) Torr, no detectable patterns were fabricated. The presence of adsorbed water at the probe/sample junction was confirmed to be crucial for the patterning of the SAM/Si. Its mechanism was, thus, ascribed to electrochemical reactions of both the SAM and Si with adsorbed water.     

基于DSP-FPGA高速控制系统的应用研究

为了满足应用对控制系统高速高精度的要求,本文将原子力显微镜作为控制对象,主要研究基于DSP—FPGA控制系统设计中的关键技术问题。包括各模块的功能划分、模块间通讯模式设计并以单行扫描为例进行编程说明。随后将PID算法嵌入FPGA,对大范围快速原子力显微镜的单点测试做闭环反馈控制。实验结果显示,与以PCI04为核心的控制系统相比,基于DSP—FPGA的控制系统大大提高了大范围快速原子力显微镜的扫描速度和控制精度。     

Mapping and control of atomic force on Si(1 1 1)square root(3) x square root(3)-Ag surface using noncontact atomic force microscope

We demonstrated the possibility of measuring the three-dimensional force-related map with true atomic resolution between an Si tip and Si(1 1 1)square root(3) x square root(3)-Ag sample surface by measuring the tip-sample distance dependence of noncontact atomic force microscope (NC-AFM) image, i.e. atomically resolved atomic force spectroscopy. Furthermore, we demonstrated the possibility of controlling the interaction force between the atom on the tip apex and a sample atom of Si(1 1 1)square root(3) x square root(3)-Ag surface on an atomic scale by placing an Ag atom on the Si tip apex instead of Si atom.     

Sample preparation for the quick sizing of metal nanoparticles by atomic force microscopy

Two alternative pretreatment methods for depositing metal nanoparticles on mica for atomic force microscopy (AFM) imaging are presented. The treated substrates are flat and clean, thus they are amenable of use to characterize very small nanoparticles. The methods do not require any instrumentation or particular expertise. As they are also very quick, the need for storage of the prepared substrates is avoided altogether. These proposed methods, which are compared with the results of transmission electron microscopy analysis, allow the quick sizing and characterization of nanoparticles with the atomic force microscope and could thus help expanding the user community of nanoparticle researchers who could use the AFM for their characterization needs.     

Effects of Electrochemistry on Surface Roughness during Chemical-Mechanical Polishing of Copper

In this research, we investigated the electrochemical behavior of copper (Cu) surfaces during chemical-mechanical polishing (CMP) with alumina containing slurries. The variation of pH and the percent of oxidizer were tested against impressed anodic and cathodic potentials. The polarization curves as well as potential and current values were measured in order to investigate the effects of electrochemical interactions during polishing. The polishing performance was evaluated through friction, wear, and surface quality. Surface characterization was conducted using an atomic force microscope. The areas scanned contained surfaces having different post-CMP surface chemistry. In such, the electrochemical, chemical, and mechanical action could be revealed and compared in situ and simultaneously. Research results showed that in acidic environment, the low pH dominated the surface roughness over oxidizer and anodic current. At high pH, however, oxidizer and anodic current played important roles. As a result, an optimized polishing condition was proposed.