Surface Topography: Metrology and Properties
Surface Topography: Metrology and Properties
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DOI：
10.1088/2051-672x/aae5b3
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发表时间：
2018-12-01
影响因子：
2.7
通讯作者：
Jacobs, Tevis D. B.
中科院分区：
文献类型：
--
作者：
Khanal, Subarna R.;Gujrati, Abhijeet;Jacobs, Tevis D. B.
多尺度表面形貌对表面功能至关重要，但传统的测量技术无法获得最小尺度的表面形貌。在这里，我们展示了在透射电子显微镜（TEM）中测量小尺度地形的两种不同方法。第一种技术利用“传统”方法制备TEM横截面，并介绍了如何修改这些方法以确保原始表面的保存。第二种技术是将感兴趣的材料沉积在预制基板上。这两种技术都能以埃级分辨率对表面形貌进行观测和量化。然后，利用电子能量损失谱（EELS）量化样品厚度，我们证明了厚度对粗糙度的统计测量没有系统的影响。通过对不同厚度的人造表面进行数学模拟，验证了这一结果。提出的解释是，增加随机粗糙表面的侧视厚度可能会改变采样的特定特征，但不会显著改变所测地形的特征（例如均方根（RMS）值和功率谱密度（PSD））。总之，这项工作建立了一种新的地形表征方法，填补了传统方法中的一个关键空白：即小尺度地形的测量。
Multi-scale surface topography is critical to surface function, yet the very smallest scales of topography are not accessible with conventional measurement techniques. Here we demonstrate two separate approaches for measuring small-scale topography in a transmission electron microscope (TEM). The first technique harnesses 'conventional' methods for preparation of a TEM cross-section, and presents how these methods may be modified to ensure the preservation of the original surface. The second technique involves the deposition of the material of interest on a pre-fabricated substrate. Both techniques enable the observation and quantification of surface topography with Angstrom-scale resolution. Then, using electron energy loss spectroscopy (EELS) to quantify the sample thickness, we demonstrate that there is no systematic effect of thickness on the statistical measurements of roughness. This result was verified using mathematical simulations of artificial surfaces with varying thickness. The proposed explanation is that increasing the side-view thickness of a randomly rough surface may change which specific features are sampled, but does not significantly alter the character (e.g. root-mean-square (RMS) values and power spectral density (PSD)) of the measured topography. Taken together, this work establishes a new approach to topography characterization, which fills in a critical gap in conventional approaches: i.e. the measurement of smallest-scale topography.