Beyond the ensemble average: X-ray microdiffraction analysis of single SiGe islands
Beyond the ensemble average: X-ray microdiffraction analysis of single SiGe islands
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DOI：
10.1103/physrevb.77.245425
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发表时间：
2008-06-01
影响因子：
3.7
通讯作者：
Boeck, T.
中科院分区：
文献类型：
--
作者：
Mocuta, C.;Stangl, J.;Boeck, T.
用X射线微区衍射仪分析了在Si(001)衬底上用液相外延生长的单个微米级SiGe岛的应变和成分分布。通过几微米大小的聚焦X射线束扫描样品时散射强度的变化，生成样品上岛屿分布的图像。使用这张图像可以识别特定的岛屿，并逐个选择它们进行分析。根据几个独立岛屿在倒易空间中的强度分布，得到了每个岛屿内的GE和应变分布。每个被测岛屿的详细形状是通过扫描电子显微镜获得的。除了截断的金字塔形状的岛屿外，我们还发现并表征了少量的平坦岛屿，表明它们代表了金字塔形状岛屿的早期生长阶段。只有在完全相同的岛屿上结合局部X射线衍射和扫描电子显微镜才有可能进行这种分析。
X-ray microdiffraction is used to analyze strain and composition profiles in individual micron-sized SiGe islands grown by liquid phase epitaxy on Si(001) substrates. From the variation of the scattered intensity while scanning the sample through a focused x-ray beam of few mu m size, an image of the island distribution on the sample is created. Using this image it is possible to identify particular islands and select them for analysis one by one. The Ge and strain distribution within each island is obtained from the intensity distribution in reciprocal space measured for several individual islands. The detailed shape of each measured island is obtained from scanning electron microscopy. Apart from truncated pyramid-shaped islands, we detect and characterize a small number of flat islands and show that they represent an earlier growth stage of the pyramidal shaped ones. This analysis is only possible by combining the local x-ray diffraction with scanning electron microscopy on exactly the same islands.