Strain relief at the GaSb/GaAs interface versus substrate surface treatment and AlSb interlayers thickness
Strain relief at the GaSb/GaAs interface versus substrate surface treatment and AlSb interlayers thickness
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DOI：
10.1063/1.3532053
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发表时间：
2011-01
影响因子：
3.2
通讯作者：
Yi Wang;P. Ruterana;L. Desplanque;S. E. Kazzi;X. Wallart
中科院分区：
文献类型：
--
作者：
Yi Wang;P. Ruterana;L. Desplanque;S. E. Kazzi;X. Wallart
利用透射电子显微镜研究了AlSb单层和衬底表面处理对GaAs（001）衬底上分子束外延生长GaSb微结构的影响。采用几何相分析方法分析了界面位错类型、残余应变以及位错核心行为随AlSb界面层厚度的变化规律。局部伯格斯矢量的定量测量表明，GaSb/GaAs界面处的错配位错始终是60°位错。它们成对排列，或多或少距离较远。对于低密度的样品，60°位错对之间的平均距离较小，界面更平坦，局部应变更缓和。这些结果表明，了解界面的原子结构可能是很大的帮助，在提高GaAs衬底上生长的GaSb的质量。
Using transmission electron microscopy we investigate the influence of AlSb monolayers and substrate surface preparation on the microstructure of GaSb grown on GaAs (001) by molecular beam epitaxy. The geometric phase analysis method is used to analyze the interface dislocation type and the residual strain, as well as the dislocation core behavior versus the thickness of the AlSb interface layer. A quantitative measurement of the local Burgers vectors shows that the misfit dislocations at the GaSb/GaAs interface are always 60° dislocations. They are arranged in pairs which are more or less distant. For the samples with the lower threading dislocation density, the average distance between the 60° pairs is smaller, the interface is flatter and the local strain is more relieved. These results show that understanding the atomic structure of interfaces may be of great help in improving the quality of GaSb grown on GaAs substrates.