扫描近场光学显微镜中探针样品间距控制方法

在动态原子力与近场光学扫描显微镜中,探针与样品的间距关系到分辨率以及扫描速度这两个最重要参数的性能。在对几种主要的动态原子力/扫描近场光学组合显微镜的探针/样品间距控制模式分析的基础上,认为提高探针Q值是提高扫描显微镜分辨率的有效方法。但是,对采用检测控制探针振幅模式,期望在提高分辨率的同时加快扫描成像速度是不可实现的,因而限制了其发展的空间。而在检测控制探针频率模式下,提高探针Q值,可有效提高扫描探针显微镜的分辨率,且不会制约扫描成像速度的提高。该结论为将来的纳米操作和纳米超高密度光存储的实用化提供了可能,对大连理工大学近场光学与纳米技术研究所研制的原子力与光子扫描隧道组合显微镜(AF/PSTM)的改进和产业化具有积极意义。     

基于自相关的AFM快速成像

原子力显微镜(AFM)的原理是利用针尖与样品表面原子间的微弱作用力来作为反馈信号,维持针尖——样品间作用力恒定,同时针尖在样品表面扫描,从而得知样品表面的高低起伏。然而,原子力显微镜得到的数据是一维的,如何从这一维的数据恢复出被扫描样本的二维图像是一个值得关心的问题。本文主要通过以自相关为核心的相关算法,以Labview为平台,快速从得到的一维数据恢复出被扫描样品的二维图像,从而为进一步的研究提供了便利。同时扩展该算法的用途以作为一种简易滤波器。     

基于多重分形谱研究十二烷基硫醇分子自组装膜在铜表面的作用行为

采用动电位扫描、原子力显微镜相位测试,基于多重分形谱,研究了十二烷基硫醇分子自组装膜在铜表面的作用行为。结果表明,在氯化钠溶液中,十二烷基硫醇分子自组装膜对铜腐蚀有显著的抑制效果,缓蚀效率随自组装时间的增加而增大。采用原子力显微镜对样品进行相位图测试,基于多重分形谱对相位图进行分析,可反映出随着自组装时间的增加,自组装膜在铜表面从部分覆盖到完全覆盖的过程。     

基于PA85A的高精度动态压电陶瓷驱动电源设计

压电陶瓷作为原子力显微镜系统中的执行器件,能够快速跟踪测量样品的形貌。为提高压电陶瓷驱动器的定位精度与响应速度,根据电压控制型驱动电源的原理,以PA85A高压运放为核心器件,设计了一种高精度动态压电陶瓷驱动电源。分析了影响系统精度与动态性能的因素,采用相位补偿法,提高了系统的稳定性。实验结果表明,该电源具有精度高,动态响应快,稳定性强的特点,能有效用于原子力显微镜系统中。     

力学性能对于原子力显微镜接近曲线的影响

该文基于Derjaguin-Muller-Toporov接触模型,研究了振幅调制原子力显微镜(AM-AFM))成像中,3种典型针尖悬臂系统与四类具有不同力学性能的材料样品在针尖样品接近过程中互作用的响应情况。研究表明相位响应与针尖样品相互作用力作用形式密切相关。通过针尖的振幅曲线可确定针尖与样品间的互作用力的性质是吸引还是排斥,本研究结果有助于在AM-AFM成像实验中优化基准值设置,以避免对样品的损害。     

状态激励轻敲模式原子力显微镜的设计与仿真

为轻敲模式原子力显微镜设计了一种激励方式,在带有状态反馈的轻敲模式原子力显微镜基础上,除去原有的外加激励信号而引入一个自动增益控制环节,用于维持状态反馈信号的幅度恒定,并将此信号作为悬臂振动的漱励信号.读激励方式即为状态激励,用于轻跛模式时可称为状态激励轻敲模式原子力显微镜.采用Matlab/Simulink工兵实现了...     

256 Gbits/in~2密度光记录的读取

现在的比特记录型光记录的记录密度受衍射极限的限制.为突破此极限,则利用近场光学对光记录进行了研究.作者提出一种专门用来读取高记录密度媒体的系统,该系统采用了无孔径近场显微镜技术.对其可行性进行了实验上和理论上的探讨,并指出可以兆赫兹的速率读取256Gbits/in~2的记录密度.系统是一种采用了原子力显微镜的反射式无孔径型近场显微镜,用光信号的相位变化读取探头与样品间的相互作用.用原子力显微镜的引力进行距离控制,探头以1～5MHz振动.在实验中,将电子束曝光获得的实验用图案(256Gbits/in~2在10nm距离的位置进行探头扫描,以30dB的S/N读取.此外,根据测定信号的谱图,可以得出能以8     

针尖扫描原子力显微镜的光点跟踪设计

提出了一种用于针尖扫描原子力显微镜(AFM)的光点跟踪设计方案,结构简单,容易实现。设计方案对扫描器的负载能力要求不高,而且能使原子力显微镜实现较大范围的针尖扫描。实验结果表明,采用此光点跟踪设计方案的针尖扫描原子力显微镜能实现最大100μm×100μm范围的扫描,z方向上的误差最大1 nm,能很好地满足大样品扫描的需要。     

CD-AFM在45nm节点半导体芯片检测过程中的应用

本文介绍了关键尺寸原子力显微镜（CD-AFM）在半导体芯片制造中的应用。通过对比现有的半导体检测仪器与原子力显微镜的工作原理和检测方法,详细探讨了原子力显微镜在目前的半导体芯片45nm节点工艺关键尺寸检测中的优势地位。根据芯片在线关键尺寸检测的具体要求,提出了原子力显微镜急待解决的相关研究内容。     

原子力显微镜及应用

原子力显微镜及应用张亦奕，贺　节，商广义，姚骏恩（中国科学院北京电子显微镜实验室，北京１０００８０）八十年代后期问世的原子力显微镜（ＡｔｏｍｉｃＦｏｒｃｅＭｉｃｒｏｓｃｏｐｅ，简称ＡＦＭ）是观察表面形貌的一种新型扫描探针显微镜。它不仅能像扫描隧道显微...     

The cell biological application of carbon nanotube probes for atomic force microscopy: comparative studies of malaria-infected erythrocytes

We describe the first cell biological application of carbon nanotube (CN) probes for atomic force microscopy studies. Topographic and phase images were collected from Plasmodium falciparum malaria-infected erythrocytes using both TappingMode Etched Silicon Probes (TESP probe) and CN probes. We estimate that the lateral resolution of a CN probe-generated topographic image is at least four-fold higher than that of the TESP probe. Carbon nanotube probe-generated phase images of P. falciparum-induced knobs on the surface of erythrocytes also show a markedly higher lateral resolution than comparable TESP probe-generate phase images of the same area. We conclude that CN probes are useful for cell biological atomic force microscopy studies and should play an increasingly important role in the future of this evolving discipline.     

Lipid membrane phase behaviour elucidated in real time by controlled environment atomic force microscopy

Lipids are integral components of all biological membranes. Understanding the physical and chemical properties of these lipids is critical to our understanding of membrane functions. We developed a new atomic force microscope (AFM) approach to visualize in real time the temperature-induced lipid phase transition and domain separation processes in 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) membranes and estimate the thermodynamics of the phase transition process. The gel and liquid crystalline phases of DMPC coexisted over a broad temperature range (approximately 10 degrees C). Equal partitioning into two phases occurred at a transition temperature (Tm) of 28.5 degrees C. We developed a mathematical model to analyse AFM-derived DMPC membrane height changes as multi-peak Gaussian distributions. This approach allowed us to estimate the DMPC domain size, N, as 18-75 molecules per leaflet corresponding to a -4.2 nm diameter circular nanodomain. Lipid nanodomains may organize into microdomains or rafts which, in concert with proteins and other lipid components, play an important dynamic role in many biomedically important processes.     

液相型AFM的研制与金属腐蚀原位研究

介绍了新型液相型原子力显微镜（AFM）的工作原理、系统结构和独特性能，讨论了该AFM在金属腐蚀研究中的应用。利用液相型AFM对碳钢在NaCl溶液及Pb在草酸溶液中的腐蚀过程进行了原位观察，获得了理想的扫描图像。实验结果表明，金属腐蚀最初起始于原子或纳米尺度，之后逐渐扩大到宏观尺度；金属表面的凹坑或缺陷可加速其腐蚀；而表面突起的结构则被一层层腐蚀。     

A new model for PCBM phase segregation in P3HT:PCBM blends

The phase segregation in P3HT:PCBM blend films has been investigated from an experimental and theoretical viewpoint. Optical microscopy, atomic force microscopy, scanning electron microscopy and X-ray diffraction show that thermal annealing of P3HT:PCBM blend films leads to the formation of PCBM aggregates. These aggregates are composed of dense randomly packed ∼50 nm PCBM crystallites with an overall aggregate density of ∼0.85 g cm⁻³. By applying the critical radius of nucleation for PCBM and the Stokes-Einstein equation for mobility of PCBM in a P3HT matrix, a model is developed which explains the formation of both crystallites and aggregates.     

64×64点阵达曼光栅的设计与实现

分析了偶数点阵达曼光栅的设计原理与特性。利用数值优化方法 ,获得了一组 6 4× 6 4点阵达曼光栅解。光栅模版用电子束制版法制成 ,其最细线宽为 2 .5 μm。用光刻法实现了这一位相光栅 ,并比较了不同位相光栅制作法的优缺点。原子力显微镜测得的光栅深度曲线与 6 4× 6 4点阵实验结果表明 ,此光栅结果接近理论值。     

固相微萃取用改性聚氨酯涂层的AFM表征

针对目前固相微萃取（SPME）商用纤维头品种单一、极性跨度小、萃取效率低等问题,本研究合成一种新型的丙烯酸改性聚氨酯材料,并采用紫外光固化技术制备SPME萃取头涂层。应用原子力显微镜（AFM）对不同组分配比的改性聚氨酯涂层进行表征。AFM观察表明,合成的丙烯酸改性聚氨酯树脂是一种具有极性硬段和非极性软段微相结构分离的聚合物,随组分配比不同,软段和硬段的相畴尺寸及其分布有所不同,涂层材料的表面形貌也有所不同。其中甲苯二异氰酸酯（TDI）和烷羟基硅油（PDMS-OH）用量比为1.5∶1时合成的涂层材料,相畴精细,极性硬段和非极性软段均匀地分布在涂层中。     

Applications of the pulsed current-voltage (I-V) and capacitance-voltage (C-V) techniques for high-resistive gates in MOSFETs

Most modern semiconductor laboratories are equipped with scanning electron or atomic force microscopes based nanoprobing systems for electrical measurement of advanced technology node devices. These nanoprobing systems use a scanning electron or an atomic force microscope in their design to image and make electrical connection to the nanoscale contacts on these devices to perform DC electrical tests and examine their electric properties. While the conventional sweep DC I-V curves can reveal most failures in MOSFETs (metal-oxide-semiconductor field-effect-transistors), DC I-V tests have been found to be insufficient for identifying high-resistive gate faults. New techniques based on the pulsed I-V and high-frequency C-V measurements have been recently developed for detecting these high-resistive gate defects in these devices. In this paper, several test samples were manufactured and later measured using both the pulsed I-V and C-V methods to confirm their applicability. Finally, several real resistive gate device failure cases were examined using these same methods.     

一步激光直写制作透射式相位光栅

利用一步激光直写灰阶光刻方法制作了具有连续浮雕结构的透射式相位光栅.原子力显微镜测量结果表明制作的透射式相位光栅具有连续外形轮廓、理想的周期和深度.飞秒激光实验系统测量的光栅的衍射效率结果表明:最大衍射角效率为66.8%、零级能量仅为入射光能量的3.3%,这在光限幅中有重要应用价值.     

High density phase change data on flexible substrates by thermal curing type nanoimprint lithography

In this study, high density phase change nano-pillar device (Tera-bit per inch² data density) was fabricated on flexible substrates by thermal curing type nanoimprint lithography with high throughput at a relatively low temperature (120 °C). Phase change nano-pillar was formed with on flexible poly (ethylene terephthalate) (PET) film, polyimide (PI) film, and stainless steel plate (SUS) substrate without any damage of substrate. The electrical property of the fabricated phase change nano-pillar device was confirmed by electrical signal measuring of conductive atomic force microscopy.