Aso Kohei, Oshima Yoshifumi
School of Materials Science, Japan Advanced Institute of Science and Technology, Asahidai 1-1, Nomi, Ishikawa 923-1292, Japan.
Microscopy (Oxf). 2025 Jan 30;74(1):57-62. doi: 10.1093/jmicro/dfae038.
Heteroepitaxial interfaces are important because they determine the performance of devices such that career mobility is sensitive to the distribution of roughness, strain and composition at the interface. High-angle annular dark field imaging in scanning transmission electron microscopy has been utilized to capture them at an atomic scale. For precise identification of atomic column positions, a technique has been proposed to average multiple image frames taken at a high scanning rate by their positional alignment for increasing signal-to-noise ratio. However, the positional alignment between frames is sometimes incorrectly estimated because of the almost perfect periodic structure at the interfaces. Here, we developed an approach for precise positional alignment, where the images are first aligned by two consecutive images and then are aligned more precisely against the integrated image of the first alignment. We demonstrated our method by applying it to the heterointerface of Si0.8Ge0.2 (Si: silicon, Ge: germanium) epitaxial thin films on a Si substrate.
异质外延界面很重要，因为它们决定了器件的性能，职业迁移率对界面处粗糙度、应变和成分的分布很敏感。扫描透射电子显微镜中的高角度环形暗场成像已被用于在原子尺度上捕捉它们。为了精确识别原子列位置，已经提出了一种技术，通过对以高扫描速率拍摄的多个图像帧进行位置对齐来平均，以提高信噪比。然而，由于界面处几乎完美的周期性结构，帧之间的位置对齐有时会被错误估计。在这里，我们开发了一种精确位置对齐的方法，首先通过两个连续图像对齐图像，然后相对于第一次对齐的积分图像更精确地对齐。我们通过将其应用于硅衬底上的Si0.8Ge0.2（Si：硅，Ge：锗）外延薄膜的异质界面来证明我们的方法。
