Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI 48824, United States.
Micron. 2011 Jul;42(5):392-400. doi: 10.1016/j.micron.2010.11.002. Epub 2010 Nov 21.
The reliability of the Computational Fourier Transform Moiré (CFTM) and Geometric Phase Analysis (GPA) techniques for strain analysis at ultra-thin layers has been investigated using computer-generated images. Our results revealed that the leakage effect creates error that is linearly dependent on the mask size used for Fourier filtering. Error due to the leakage effect has a significant impact on the analysis of strain for small-mismatched systems with low resolution in the original image. We demonstrate that the error due to the leakage effect can be minimized with improved resolution of the original image. In order to obtain a measurement of the reliability of the CFTM and GPA methods on ultra-thin layers, we systematically quantify the error due to the leakage effect as a function of image resolution and applied strain value for the original image. The presence of the leakage effect and the resulting limitations of the CFTM and GPA methods are demonstrated using a high-resolution transmission electron microscopy (HRTEM) image of an ultra-thin heterointerface from a strained layer superlattice.
我们使用计算机生成的图像研究了计算傅里叶变换云纹（CFTM）和几何相位分析（GPA）技术在超薄膜应变分析中的可靠性。研究结果表明，漏泄效应会产生误差，该误差与用于傅里叶滤波的掩模尺寸线性相关。对于原始图像分辨率较低、失配较小的系统，漏泄效应引起的误差会对应变分析产生显著影响。我们证明，通过提高原始图像的分辨率，可以最小化漏泄效应引起的误差。为了在超薄膜上获得 CFTM 和 GPA 方法可靠性的测量结果，我们系统地量化了漏泄效应引起的误差，作为图像分辨率和原始图像应用应变值的函数。通过对应变层超晶格中一个超薄膜异质界面的高分辨率透射电子显微镜（HRTEM）图像的分析，证明了漏泄效应的存在及其对 CFTM 和 GPA 方法的限制。
