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1.
原子力显微镜探针原位有效参数对线宽测量的修正 总被引:1,自引:0,他引:1
针对原子力显微镜(AFM)的线宽和轮廓的精确测量,对AFM探针的原位有效参数进行了定义和表征,提出使用AFM探针的原位有效参数对AFM的线宽测量结果进行修正的模型。采用有效半径和半内角表征AFM探针的复合形状,悬臂轴倾角表征探针的安装状态,设计了具有不同梯形截面的两个表征样板,通过对表征样板进行AFM和扫描电子显微镜(SEM)的比对测量获得了探针的原位有效参数。提出了在线宽测量中,当AFM的扫描轮廓线具有不同的斜度时分别采用的不同的修正公式。采用此公式和探针的原位参数对掩膜板的AFM线宽测量结果进行了修正。 相似文献
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详细分析了P47型原子力显微镜线宽测量不确定度的来源,给出了基于几何形状的线宽测量模型,提出了线宽测量不确定度的评定路线和方法。确定了探针针尖引起的测量不确定度是AFM线宽测量不确定度的主要来源,并对其进行了定量分析。普通Si3N4探针针尖引起的不确定度分量约占线宽总量的5%。 相似文献
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《纳米技术与精密工程》2018,(2)
Blind tip reconstruction(BTR) method is one of the favorable methods to estimate the atomic force microscopy(AFM) probe shape. The exact shape of the characterizer is not required for BTR, while the geometry of the sample may affect the reconstruction significantly. A cone-shaped array sample was chosen as a characterizer to be evaluated. The target AFM probe to be reconstructed was a diamond triangular pyramid probe with two feature angles, namely front angle(FA) and back angle(BA). Four conical structures with different semi-angles were dilated by the pyramid probe. Simulation of scanning process demonstrates that it is easy to judge from the images of the isolated rotary structure, cone-shaped, the suitability of the sample to be a tip characterizer for a pyramid probe. The cone-shaped array sample was repeatedly scanned 50 times by the diamond probe using an AFM. The series of scanning images shrank gradually and more information of the probe was exhibited in the images, indicating that the characterizer has been more suitable for BTR. The feature angle FA of the characterizer increasingly reduces during the scanning process. A self-adaptive grinding between the probe and the characterizer contributes to BTR of the diamond pyramid probe. 相似文献
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纳米栅格和台阶等结构的线宽准确测量,是国内外计量领域的研究热点与难点。采用原子力显微镜(AFM)能获得上述结构的三维形貌信息,但其扫描图像却是探针针尖的形貌和被测样品表面的形貌共同作用的结果,这种作用往往导致线宽边缘测量失真。为了更加精确地获得样品的表面形貌特征,首先需要重建探针针尖形貌,进而从得到的扫描图像中尽可能地消除由探针形貌带来的失真影响。基于数学形态学的盲重建理论,利用Matlab对不同形状参数的探针针尖扫描台阶样品表面进行了仿真,评价了探针形状对扫描结果的影响,初步实现了基于真实粗糙测量表面的探针针尖形状重建。 相似文献
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J. S. Villarrubia 《Journal of research of the National Institute of Standards and Technology》1997,102(4):425-454
To the extent that tips are not perfectly sharp, images produced by scanned probe microscopies (SPM) such as atomic force microscopy and scanning tunneling microscopy are only approximations of the specimen surface. Tip-induced distortions are significant whenever the specimen contains features with aspect ratios comparable to the tip’s. Treatment of the tip-surface interaction as a simple geometrical exclusion allows calculation of many quantities important for SPM dimensional metrology. Algorithms for many of these are provided here, including the following: (1) calculating an image given a specimen and a tip (dilation), (2) reconstructing the specimen surface given its image and the tip (erosion), (3) reconstructing the tip shape from the image of a known “tip characterizer” (erosion again), and (4) estimating the tip shape from an image of an unknown tip characterizer (blind reconstruction). Blind reconstruction, previously demonstrated only for simulated noiseless images, is here extended to images with noise or other experimental artifacts. The main body of the paper serves as a programmer’s and user’s guide. It includes theoretical background for all of the algorithms, detailed discussion of some algorithmic problems of interest to programmers, and practical recommendations for users. 相似文献
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Sizes correction on AFM images of nanometer spherical particles 总被引:1,自引:0,他引:1
De-Quan Yang Yu-Qing Xiong Yun Guo Da-An Da Wei-Gang Lu 《Journal of Materials Science》2001,36(1):263-267
Atomic Force Microscopy (AFM) is widely used in morphology characterization of materials on nanometer and sub-micron scales. However, distortions universally exist in AFM images due to geometrical interaction between the sample surface and the limited size tip. Correction factors for AFM images are given in the paper based on a simple mathematical model. The results reveal that the correction factors are related with the distribution of the particles (compacted or dispersed). The distortions can cause bigger images than the real sizes using commercial pyramidal tips and the distortions are deflation under certain conditions as well. The distortions of the images are affected by the shape of the AFM tip and circumstance of the particles. The results are compared the experimental data. 相似文献
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Jinhui Song Huizhi Xie Wenzhuo Wu V. Roshan Joseph C. F. Jeff Wu Zhong Lin Wang 《Nano Research》2010,3(9):613-619
Nanogenerators were first demonstrated by deflecting aligned ZnO nanowires using a conductive atomic force microscopy (AFM)
tip. The output of a nanogenerator is affected by three parameters: tip normal force, tip scanning speed, and tip abrasion.
In this work, systematic experimental studies have been carried out to examine the combined effects of these three parameters
on the output, using statistical design of experiments. A statistical model has been built to analyze the data and predict
the optimal parameter settings. For an AFM tip of cone angle 70° coated with Pt, and ZnO nanowires with a diameter of 50 nm
and lengths of 600 nm to 1 μm, the optimized parameters for the nanogenerator were found to be a normal force of 137 nN and
scanning speed of 40 μm/s, rather than the conventional settings of 120 nN for the normal force and 30 μm/s for the scanning
speed. A nanogenerator with the optimized settings has three times the average output voltage of one with the conventional
settings. 相似文献
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针对原子力显微镜(AFM)纳米成像中存在的失真问题,研究了通过探针建模实现AFM扫描图像重构方法.目前探针盲建模算法在重构AFM图像时存在较大误差,因此提出基于探针模型预估计的AFM扫描图像重构方法.该方法采用分区探针针尖建模,并通过基于该探针模型的反卷积运算实现AFM扫描图像重构,获得比较接近真实形貌的AFM扫描图像.文中介绍了算法的具体步骤,通过仿真和实验结果证明,该方法能够有效降低AFM图像重构时引入的误差,得到的图像更能反映样品表面真实的形貌. 相似文献
11.
Alex A. Volinsky Neville R. Moody William W. Gerberich 《International Journal of Fracture》2003,120(1-2):431-439
Carbon fiducial marks are formed during thin film local delamination processes induced either by superlayer indentation forming circular blisters, or by residual stress relief through telephone cord blister formations. Hydrocarbons are sucked into the crack tip during the delamination process, outlining the crack tip opening angle (CTOA), which can be used to back calculate thin film adhesion using either elastic or plastic analyses presented here. Fiducial marks have been observed in two different thin films systems, namely Cu/SiO2 and TiWXNY/GaAs.TiWXNY/GaAs system also exhibited biaxial compressive stress-induced phone cord buckling delaminations. Surface AFM CTOA measurement approach is used to estimate the strain energy release rate increase along these phone cords delaminations. 相似文献
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In 2004 Hembacher et al. (Science 2004, 305, 380-383) reported simultaneous higher-harmonics atomic force mocroscopy (AFM)/scanning tunneling microscopy (STM) images acquired while scanning a graphite surface with a tungsten tip. They interpreted the observed subatomic features in the AFM images as the signature of lobes of increased electron density at the tungsten tip apex. Although these intriguing images have stirred controversy, an in-depth theoretical feasibility study has not yet been produced. Here we report on the development of a method for simulating higher harmonics AFM images and its application to the same system. Our calculations suggest that four lobes of increased electron density are expected to be present at a W(001) tip apex atom and that the corresponding higher harmonics AFM images of graphite can exhibit 4-fold symmetry features. Despite these promising results, open questions remain since the calculated amplitudes of the higher harmonics generated by the short-range forces are on the order of hundredths of picometers, leading to very small corrugations in the theoretical images. Additionally, the complex, intermittent nature of the tip-sample interaction, which causes constant readjustment of the tip and sample orbitals as the tip approaches and retracts from the surface, prevents a direct quantitative connection between the electron density and the AFM image features. 相似文献
13.
Spatially correlated fluorescence/AFM of individual nanosized particles and biomolecules 总被引:2,自引:0,他引:2
Individual fluorescent polystyrene nanospheres (<10-100-nm diameter) and individual fluorescently labeled DNA molecules were dispersed on mica and analyzed using time-resolved fluorescence spectroscopy and atomic force microscopy (AFM). Spatial correlation of the fluorescence and AFM measurements was accomplished by (1) positioning a single fluorescent particle into the near diffraction-limited confocal excitation region of the optical microscope, (2) recording the time-resolved fluorescence emission, and (3) measuring the intensity of the excitation laser light scattered from the apex of an AFM probe tip and the AFM topography as a function of the lateral position of the tip relative to the sample substrate. The latter measurements resulted in concurrent high-resolution (approximately 10-20 nm laterally) images of the laser excitation profile of the confocal microscope and the topography of the sample. Superposition of these optical and topographical images enabled unambiguous identification of the sample topography residing within the excitation region of the optical microscope, facilitating the identification and structural characterization of the nanoparticle(s) or biomolecule(s) responsible for the fluorescence signal observed in step 2. These measurements also provided the lateral position of the particles relative to the laser excitation profile and the surrounding topography with nanometer-scale precision and the relationship between the spectroscopic and structural properties of the particles. Extension of these methods to the study of other types of nanostructured materials is discussed. 相似文献
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为了提高串联工业机器人的绝对定位精度,提出了采用轴线测量与迭代补偿相结合的工业机器人几何参数标定方法。首先利用激光跟踪仪测量机器人单轴运动的轨迹,将所测轨迹点通过空间投影计算各轴线的位置;然后根据机器人模型参数的几何定义提取机器人模型的实际参数,并采用基于距离误差的迭代补偿方法进行参数标定效果验证。对埃夫特ER10L-C10工业机器人进行标定实验研究,结果表明:机器人绝对定位误差的最大值、平均值和标准差分别从补偿前的4.215、1.932和1.437 mm减小到补偿后的2.979、1.015和1.031 mm,该方法能够简单快速标定出机器人模型的实际几何参数,有效提高了机器人的绝对定位精度。 相似文献
17.
J. F. Song F. F. Rudder Jr. T. V. Vorburger J. H. Smith 《Journal of research of the National Institute of Standards and Technology》1995,100(5):543-561
National and international comparisons in Rockwell hardness tests show significant differences. Uncertainties in the geometry of the Rockwell diamond indenters are largely responsible for these differences. By using a stylus instrument, with a series of calibration and check standards, and calibration and uncertainty calculation procedures, we have calibrated the microform geometric parameters of Rockwell diamond indenters. These calibrations are traceable to fundamental standards. The expanded uncertainties (95 % level of confidence) are ±0.3 μm for the least-squares radius; ±0.01° for the cone angle; and ±0.025° for the holder axis alignment calibrations. Under ISO and NIST guidelines for expressing measurement uncertainties, the calibration and uncertainty calculation procedure, error sources, and uncertainty components are described, and the expanded uncertainties are calculated. The instrumentation and calibration procedure also allows the measurement of profile deviation from the least-squares radius and cone flank straightness. The surface roughness and the shape of the spherical tip of the diamond indenter can also be explored and quantified. Our calibration approach makes it possible to quantify the uncertainty, uniformity, and reproducibility of Rockwell diamond indenter microform geometry, as well as to unify the Rockwell hardness standards, through fundamental measurements rather than by performance comparisons. 相似文献
18.
Crack tip opening angle (CTOA) is becoming one of the more widely accepted properties for characterizing fully plastic fracture. In fact, it has been recognized as a measure of the resistance of a material to fracture in cases where there is a large degree of stable-tearing crack extension during the fracture process.Our current pipeline research uses the CTOA concept as an alternative or an addition to the fracture energy characterizations provided by the Charpy V-notch (CVN) and drop weight tear test (DWTT). A test technique for direct measurement of CTOA was developed by use of a modified double cantilever beam (MDCB) specimen. A digital camera and image analysis software were used to record the progression of the crack tip and to estimate CTOA. In this report, different optical measurement methods are compared, three using the crack edges adjacent to the crack tip (defined in the ISO draft standard and ASTM standard) and one using the specimen surface grid lines. Differences in CTOA resulting from the various measurement methods are evaluated. The CTOAs for five different grades of gas pipeline steel are reported, and the effect of microstructure on CTOA is discussed. 相似文献
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PH. P. DARCIS C. N. MCCOWAN J. D. MCCOLSKEY R. FIELDS 《Fatigue & Fracture of Engineering Materials & Structures》2008,31(12):1065-1078
Crack tip opening angle (CTOA) is becoming one of the most accepted methods for characterizing fully plastic fracture. It provides a measure of the resistance to fracture for a material in cases where there is a large degree of stable‐tearing crack extension during the fracture process. Our current pipeline research uses the CTOA test as an alternative, or addition, to the CTOD (crack tip opening displacement) and the fracture energy characterization provided by the J‐integral approach. A test technique was developed for measurement of CTOA that uses a modified double cantilever beam (MDCB) specimen. A digital camera and image analysis software were used to record the progression of the crack tip and to estimate the CTOA. In this article, CTOA data on crack growth orientations perpendicular to pipeline girth welds are presented. The CTOA for X100 high strength bainitic gas pipeline steel is reported. Two different specimen gauge sections, 3 mm and 8 mm, were used and the effect of the specimen thickness on the CTOA is discussed. The results show a change in the CTOA as the crack grows into the heat affected zone (HAZ). A slight improvement in the fracture resistance is measured, and through the weld, a slight decrease in fracture resistance is observed. 相似文献
20.
Hunter AJ Drinkwater BW Wilcox PD 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2011,58(2):414-426
Ultrasonic array images are adversely affected by errors in the assumed or measured imaging parameters. For non-destructive testing and evaluation, this can result in reduced defect detection and characterization performance. In this paper, an autofocus algorithm is presented for estimating and correcting imaging parameter errors using the collected echo data and a priori knowledge of the image geometry. Focusing is achieved by isolating a known geometric feature in the collected data and then performing a weighted leastsquares minimization of the errors between the data and a feature model, with respect to the unknown parameters. The autofocus algorithm is described for the estimation of element positions in a flexible array coupled to a specimen with an unknown surface profile. Experimental results are shown using a prototype flexible array and it is demonstrated that (for an isolated feature and a well-prescribed feature model) the algorithm is capable of generating autofocused images that are comparable in quality to benchmark images generated using accurately known imaging parameters. 相似文献