海藻酸薄膜表面超微结构的原子力显微镜研究

本文采用原子力显微镜（ＡＦＭ）对海藻酸生物薄膜表面的超微结构进行了实验研究,选择出最佳观察方法。结果发现薄膜上分布不规则的微孔,其长短孔径之比大约为３：２,微孔的中心距为孔径的２倍。     

原子力显微镜相位成像模式的设计及研究

相位成像模式是近几年发展起来的一种原子力显微镜的检测模式,该模式可以提供丰富的样品表面纳米尺度信息,是形貌像的有利补充。本文给出了一种应用原子力显微镜轻敲模式的相位检测电路,结构简单,工作可靠稳定。通过实验获得了一些样品的相位像。     

金纳米粒子有序膜结构的原子力显微研究

通过控制所滴加的金纳米粒子氯仿溶胶的浓度,在高序定向裂解石墨（HOPG）上,可以形成二维乃至三维有序的金纳米粒子膜结构,本文主要利用原子力显微镜中的轻敲原子力（TM－AFM）显微模式,采用形貌与相位同时成像技术以及透射电镜技术,对所形成的有序膜结构进行了系统的表征,并着重阐述了相应成像在表征膜结构方面的重要作用。     

高速原子力显微术研究进展

自1986年发明原子力显微镜以来,它已成为材料、生物以及纳米科技等许多领域的重要工具。由于常规原子力显微镜成像速度缓慢,在动态过程观测、工业生产线原位测量以及高密度信息存储等领域的应用受到限制,因此发展高速原子力显微术近年来已引起国内外的高度关注。本文综述了高速原子力显微术关键技术(包括:微小探针、高速扫描器设计和控制方法)以及应用等方面的最近进展。     

Thermal detection of device failure by atomic force microscopy

Device and interconnect electrical failures often occur in the form of short or open circuits which produce hot or cold spots under voltage bias. With the minimum device feature size shrinking to 0.25 μm and less, it is impossible to locate the exact position of defects by traditional thermal or optical techniques such as infra-red emission thermometry, liquid crystals or optical beam induced current. We have used a temperature-sensing probe in an atomic force microscope to locate a hot spot created by a short-circuit defect between the gate and the drain of a Si MOSFET with a spatial resolution of about 0.5 μm. The technique has the potential to produce spatial resolutions in the range of 0.05 μm and efforts are underway to reach this goal     

Local oxidation of titanium films by non-contact atomic force microscopy

Characteristics of local nanolithography on oxidative titanium dots and wires were studied using an amplitude modulation atomic force microscopy in the non-contact mode. Nanolithographic experiments were conducted to investigate the influence that different experimental parameters had on the height, the width, the growth rate, the morphology, and the composition of the nanostructures using Auger electron spectroscopy. The results indicate that anodization time, applied voltage, and tip-sample distance are proportional to the heights and widths of the dots. When the tip-sample distance was too close during continued anodization, concave dots appeared because the oxide that enclosed the tip. Carbon nanotube probe fabricated dots are also presented and compared.     

Control of interaction force in constant-height contact mode atomic force microscopy

Contact mode is a versatile and widely used technique for imaging samples using the Atomic Force Microscope (AFM). When contact mode imaging is performed in constant-height mode, it enables linear and faster response but leads to uncontrolled tip-sample forces. Here, a control strategy based on magnetic actuation is proposed to achieve high-bandwidth control of the tip-sample forces in constant-height contact mode AFM. A magnetic particle attached to the AFM probe is actuated by an external solenoid and employed for force regulation. A quasi-static model has been proposed and employed to develop the control strategy. Likewise, the contact natural-frequency, which decides the limit of achievable speed, has been shown to be significantly higher relative to the free probe and to be relatively insensitive to the particle size. Subsequently, a setup is developed to validate the control strategy and demonstrate reduction of tip-sample force variation by over a factor of 12 compared to conventional constant-height mode operation. Likewise, in comparison with conventional contact mode AFM, an improvement of linearity by over a factor of 9 and improvement in response speed by a factor of 100 have been demonstrated while imaging hard samples. The system has been shown to image topography at speeds of 2.44 frames per second while regulating the interaction force. Finally, the stiffness of a sample has also been characterized using the developed system and simultaneous estimation of topography has also been demonstrated. They are shown to agree well with theoretical expectations.     

Observations of xenon gas-treated barley cells in solution by atomic force microscopy

Barley cells cut from a sprout were exposed to either air or high-pressure xenon gas for 3 days and the surface of those cells was observed by atomic force microscopy (AFM) to examine the effect of the gas treatment. This method enabled the direct observation of the fresh surface of the barley cells in solution at high resolution. The cuticle layer was preserved on the primary cell wall of 0.48 MPa xenon gas-treated barley cells, while air-treated barley cells lost the cuticle layer from the primary cell wall. These findings indicate that the high-pressure xenon gas treatment is effective to preserve the cuticle layer attached to the primary cell wall. AFM is a powerful tool for the observation of the surface structure of living plant cells in solution.     

Nano-scale fluctuations in electron beam resist pattern evaluated by atomic force microscopy

The resist pattern fluctuations on the nano-scale are successfully observed using a dynamic force mode AFM. A scaling analysis based on the fractals applies to the AFM images for quantitative evaluation of the fluctuations. The standard deviation of width fluctuations in a ZEP resist pattern is 2.8 nm. The scaling analysis confirms that the surface morphology of the pattern sidewall is almost the same as that of the resist film lightly exposed by an electron beam. The main cause of the fluctuation is structures with a diameter of 20–30 nm which are composed of large groups of molecules.     

纳米颗粒填充的PTFE微结构的原子力显微镜测量

本文报道了用原子力显微镜(AFM)研究多种纳米微粒填充的聚四氟乙烯(PTFE)材料的结构组成，观察了在纳米颗粒填充的PTFE中，纳米微粒的分散不均匀性以及纳米粉末在与PTFE混合、压制后发生的团聚现象。     

利用原子力显微镜鉴别相变诱发塑性钢的显微组织

相变诱发塑性（TRIP）钢比双相钢具有更高强度和塑性，因此TRIP钢在汽车工业中的应用对于汽车轻量化有重要的经济意义。TRIP钢的高强度和高延展性主要来源于钢中复杂的显微组织以及应变条件下亚稳态的残余奥氏体（A1）向马氏全（M）的转变，即相变诱发塑性。钢中各相组织的正确鉴别显得尤为重要，特别是钢中残余奥氏体的含量、分布及其稳定性直接关系到TRIP钢性能的好坏。根据目前使用的常规鉴别方法、     

原子力显微镜对不同条件下果胶微粒的表面形态学观察

果胶是由D-半乳糖醛酸残基经α(1→4)键相连接聚合而成的酸性大分子多糖，并且半乳糖醛酸C6上的羧基有许多是甲酯化形式，根据酯化度DE值可将果胶分为高甲酯果胶(DE值高于50％)和低甲酯果胶(DE值低于50％)。果胶在食品工业中的作用主要表现在增稠、胶凝和稳定。     

In-situ etching observation of human teeth in acid agent by atomic force microscopy

Atomic force microscopy was applied to the in-situ observation of the etching process of human teeth by acid agents. The change of surface morphology was observed consecutively before and during etching for the same area in the same specimen. The course of the etching process in enamel from dissolution of smear layer just after injection of acid agent, appearance of enamel prisms and progress of demineralization were quantitatively analysed for three fundamental acid agents of 2% phosphoric acid, 10% citric acid and 10% polyacrylic acid. Then the depth profile, etching amount, etching rate and thickness of smear layer were evaluated. Observation by scanning electron microscopy was also done and compared with the results by atomic force microscopy.     

基于原子力显微镜技术的单个生物大分子压弹性研究

单个生物大分子力学性质已经成为一个新兴的研究领域,近几年来由于单分子技术的不断发展,这个领域取得了很多突破性的进展。本文介绍了基于原子力显微镜技术的几种单分子压弹性测量技术及这些技术的具体应用,同时也简要阐述了这些技术的局限性。另外对这个领域的发展也进行了初步地探讨。     

AFM反馈系统仿真模型的建立及实验

原子力显微镜（ AFM）广泛应用于纳米尺度的成像和操纵,其较低的扫描速度严重影响了测试的效率。为此,许多研究人员通过设计先进的Z向控制算法改善系统的响应速度,达到提高扫描速度的目的,而先进的控制算法的实现首先需要对AFM的Z向反馈系统进行建模。为此,本文提出一种简单准确的系统辨识方法,通过对系统输入输出数据的分析,得到AFM的Z向反馈系统模型,并利用该模型验证先进控制算法的控制性能。实验表明该方法能为先进控制算法的设计和实现建立有效的仿真模型。     

Structure of rice starch granules in nanometre scale as revealed by atomic force microscopy

Atomic force microscopy (AFM) was performed for the analysis of the fine structure of rice starch granules in the nanometre scale which were prepared by a physical destruction method. The present study directly demonstrated that fine particles of approximately 30 nm in diameter were present inside each granule and occasionally formed straight chain arrangements. We considered that these fine particles correspond to the individual single cluster in the cluster model which has been proposed in previous studies on the starch granule structure.     

Transient four-wave mixing and real time holography in atomic systems

The problem of transient four-wave mixing with noncoincident optical pulses is analyzed using the formalism of the time evolution and the density matrix operators. The results are relevant to problems involving real time holography and wave conjugation. The treatment establishes a bridge between the conventional formalisms of nonlinear optics and of photon echoes.     

女贞子多糖结构的原子力显微镜研究

水提女贞子粗多糖经过纯化得到三种多糖分别为LL-Ⅰ1,LL-Ⅰ2,LL-Ⅲ。用气相色谱对女贞子多糖组分进行分析,用原子力显微镜对其结构形态进行观测,结果表明,LL-Ⅰ1,含有鼠李糖/核糖、阿拉伯糖、甘露糖、葡萄糖和半乳糖;LL-Ⅰ2,含有鼠李糖/核糖和葡萄糖;LL-Ⅲ含有鼠李糖/核糖、阿拉伯糖、甘露糖、葡萄糖和半乳糖。原子力显微镜分析表明LL-Ⅰ1,LL-Ⅰ2,LL-Ⅲ分别不同程度的聚集成股,且具有螺旋结构。这种现象可能与聚集体的分子间相互作用和糖链间的氢键缔合有关。     

利用原子力显微镜制备短沟道有机场效应晶体管器件的研究

利用原子力显微镜(AFM)探针直写技术制备了短沟道并五苯有机场效应晶体管(OFET),并研究了器件性能。在SiO2/n+-Si基底上,利用AFM探针刻蚀金沟道,通过优化工艺参数,获得的沟道长约1μm,器件的场效应迁移率为0.038cm2.V-1.S-1,开关比为103,输出电流最高可达200μA。结果表明,器件性能强烈依赖于沟道长度,随着沟道长度减小,输出电流显著增加。     

Characterization of defects in flexible circuits with ultrasonic atomic force microscopy

Flexible circuit technology is a key factor in the continued shrinkage of microelectronic components and devices. One of the important applications of the flexible circuits is in hard disk drive industry, where they are used as an interconnection between the preamplifier and head slider assembly of a hard disk drive. At present, defect characterization of flexible circuits is often performed after manufacture usually with optical microscopy. While this may be sufficient for certain low-tech applications, for advanced ultra high-density hard disk components may not be enough. With a continuing reduction of the dimension of the current carrying conductor wires, the size of defects that may affect long-term reliability of the system is reaching the resolution limit of traditional techniques used to characterize the defects. This paper presents combined application of atomic force microscope (AFM) and ultrasonic atomic force microscope (UAFM) to characterize defects in flexible circuits. Three identical flexible circuits from different manufactures are examined using AFM and UAFM. The AFM and UAFM images of a particular region, in the flexible circuit in all the three samples are compared. Images from pure polymer region of the flexible circuit are compared with the images of the regions containing copper and polymer. In general, the UAFM images show subsurface features while AFM images show surface topography. This capability of UAFM can be used to image the grain structure of the copper film without removing the polymer cover layer film. It also detects the sub-micron defects present at the polymer/metal interface. Analysis of the grain structure of copper, distribution of defects at the polymer/metal interface is presented. Based on these observations, the applicability of AFM/UAFM to image the microstructure of copper in flexible circuits and possible effect of defects in flexible circuits on the long-term reliability of the hard disc drive are discussed.