The intrinsic resolution limit in the atomic force microscope: implications for heights of nano-scale features.
The intrinsic resolution limit in the atomic force microscope: implications for heights of nano-scale features.
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原子力显微镜的内在分辨率极限：对纳米级特征高度的影响。
DOI：
10.1371/journal.pone.0023821
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发表时间：
2011
期刊：
影响因子：
3.7
通讯作者：
Thomson NH
中科院分区：
文献类型：
--
作者：
Santos S;Barcons V;Christenson HK;Font J;Thomson NH
原子力显微镜在最高的空间分辨率下精确的机械表征要求形貌从压痕中去卷积。原子力显微镜（AFM）中纳米尺度特征的测量高度几乎总是小于真实值，这通常被解释为样品变形、盐沉积物的形成和/或脱水。我们表明，纳米物体的真实的高度不能直接获得：结果所产生的局部探针样品的几何形状的后果。我们已经将尖端-表面-样品相互作用建模为尖端与表面以及尖端与样品之间的相互作用的总和。我们发现，AFM的动力学不能区分由1）表面的化学和/或机械特性或2）由于样品的尺寸而导致的形貌中的步骤所产生的力的差异;一旦特征的尺寸变得小于AFM针尖和样品之间的有效相互作用区域，则测量的高度会受到影响。这种一般结果是高度损失的主要原因，对于纳米级特征，其损失可高达90%。特别地，即使当没有样品变形时，也可能发生高度损失的这些非常大的值，并且更一般地，高度损失与样品变形不相关。DNA和IgG抗体已被用作模型样品，其中实验高度测量结果显示与预测的现象密切匹配。能够测量单个纳米尺度特征的真实高度在许多纳米技术应用中是至关重要的，因为纳米尺度中的现象和性质严重依赖于尺寸。我们的方法可以准确预测纳米级物体的真实高度，并将导致可靠的机械特性在最高的空间分辨率。
Accurate mechanical characterization by the atomic force microscope at the highest spatial resolution requires that topography is deconvoluted from indentation. The measured height of nanoscale features in the atomic force microscope (AFM) is almost always smaller than the true value, which is often explained away as sample deformation, the formation of salt deposits and/or dehydration. We show that the real height of nano-objects cannot be obtained directly: a result arising as a consequence of the local probe-sample geometry. We have modeled the tip-surface-sample interaction as the sum of the interaction between the tip and the surface and the tip and the sample. We find that the dynamics of the AFM cannot differentiate between differences in force resulting from 1) the chemical and/or mechanical characteristics of the surface or 2) a step in topography due to the size of the sample; once the size of a feature becomes smaller than the effective area of interaction between the AFM tip and sample, the measured height is compromised. This general result is a major contributor to loss of height and can amount to up to ∼90% for nanoscale features. In particular, these very large values in height loss may occur even when there is no sample deformation, and, more generally, height loss does not correlate with sample deformation. DNA and IgG antibodies have been used as model samples where experimental height measurements are shown to closely match the predicted phenomena. Being able to measure the true height of single nanoscale features is paramount in many nanotechnology applications since phenomena and properties in the nanoscale critically depend on dimensions. Our approach allows accurate predictions for the true height of nanoscale objects and will lead to reliable mechanical characterization at the highest spatial resolution.
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影响因子：
2.2
作者：
Moreno-Herrero, F;Colchero, J;Baró, AM
通讯作者：
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通讯作者：
Proksch, Roger
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通讯作者：
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通讯作者：
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