Evolution of GaSb epitaxy on GaAs(001)‐c(4×4)
Evolution of GaSb epitaxy on GaAs(001)‐c(4×4)
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GaAs(001)-c(4×4)上GaSb外延的演化
DOI：
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发表时间：
1996
期刊：
影响因子：
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通讯作者：
L. Whitman
中科院分区：
文献类型：
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作者：
P. Thibado;B. R. Bennett;M. Twigg;B. V. Shanabrook;L. Whitman
通过扫描隧道显微镜原位和透射电子显微镜异位研究了 490°C 在 GaAs(001)-c(4×4) 上通过分子束外延生长 GaSb 薄膜。当薄膜沉积时，观察到四种不同的生长方式：前两个单层逐层生长，形成片状二维（2D）岛；下一个单层形成相干应变的三维（3D）量子点；进一步沉积导致薄膜松弛和粗糙的 3D 生长；对于薄膜厚度≳100 nm，生长再次是二维的，通过围绕新出现的螺纹位错的螺旋生长进行。讨论了生长状态之间的转变所固有的原子尺度机制。提出了旨在提高量子点均匀性和降低位错密度的生长过程的变化。
The growth of GaSb films by molecular beam epitaxy on GaAs(001)‐c(4×4) at 490 °C has been studied in situ with scanning tunneling microscopy and ex situ with transmission electron microscopy. As the film is deposited, four distinct growth regimes are observed: the first two monolayers grow layer by layer with platelet‐like two‐dimensional (2D) islands; the next monolayer forms coherently strained three‐dimensional (3D) quantum dots; further deposition induces film relaxation and rough 3D growth; for film thicknesses ≳100 nm the growth is again 2D, proceeding via spiral growth around emerging threading dislocations. The atomic‐scale mechanisms inherent in the transitions between the growth regimes are discussed. Variations in growth procedures aimed at improving the quantum dot uniformity and reducing the dislocation density are proposed.