Segregation and Interdiffusion of in Atoms in GaAs/InAs/GaAs Heterostructures
Segregation and Interdiffusion of in Atoms in GaAs/InAs/GaAs Heterostructures
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GaAs/InAs/GaAs异质结构中原子的偏析和相互扩散
DOI：
10.1557/proc-312-113
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
K. Pak
中科院分区：
文献类型：
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作者：
T. Kawai;H. Yonezu;Y. Ogasawara;D. Saito;K. Pak
用二次离子质谱法研究了GaAs/InAs/GaAs异质结构中In原子的偏析和相互扩散。当1 ML厚的InAs层在无位错的逐层生长模式下生长时，随着生长温度的升高，in原子的偏析变得明显。然而，在分子束外延中，即使在相对较低的生长温度（400℃）下，也观察到偏析现象。结果表明，当以三维岛生长方式生长时，在异质界面附近的位错使偏析明显增强。热退火后，In原子向生长方向扩散，空位从薄膜表面扩散到后处理层。结果表明，在GaAs帽层中插入薄的AlAs层可以有效地抑制相互扩散。
The segregation and interdiffusion of In atoms in the GaAs/InAs/GaAs heterostructures were investigated by secondary‐ion mass spectroscopy. When the 1‐ML‐thick InAs layer was grown in a layer‐by‐layer growth mode with no dislocations, the segregation of In atoms became marked with the increase of the growth temperature. However, the segregation was observed even at a relatively low growth temperature of 400 °C in molecular beam epitaxy. It was found that the segregation was markedly enhanced by dislocations near the heterointerface when thick InAs layers were grown in a three‐dimensional island growth mode. The interdiffusion of In atoms toward the growth direction occurred after thermal annealing, which could be assisted by vacancies propagating from the film surface into the epilayer. It became apparent that the interdiffusion was effectively suppressed by a thin AlAs layer inserted in the GaAs cap layer.