Petrushkov Mikhail O, Abramkin Demid S, Emelyanov Eugeny A, Putyato Mikhail A, Komkov Oleg S, Firsov Dmitrii D, Vasev Andrey V, Yesin Mikhail Yu, Bakarov Askhat K, Loshkarev Ivan D, Gutakovskii Anton K, Atuchin Victor V, Preobrazhenskii Valery V
Laboratory of Physical Bases of Semiconductor Heterostructures Epitaxy, Institute of Semiconductor Physics, SB RAS, Novosibirsk 630090, Russia.
Laboratory of Molecular Beam Epitaxy of A3B5 Compounds, Institute of Semiconductor Physics, SB RAS, Novosibirsk 630090, Russia.
Nanomaterials (Basel). 2022 Dec 14;12(24):4449. doi: 10.3390/nano12244449.
The use of low-temperature (LT) GaAs layers as dislocation filters in GaAs/Si heterostructures (HSs) was investigated in this study. The effects of intermediate LT-GaAs layers and of the post-growth and cyclic in situ annealing on the structural properties of GaAs/LT-GaAs/GaAs/Si(001) HSs were studied. It was found that the introduction of LT-GaAs layers, in combination with post-growth cyclic annealing, reduced the threading dislocation density down to 5 × 10 cm, the root-mean-square roughness of the GaAs surface down to 1.1 nm, and the concentration of non-radiative recombination centers in the near-surface GaAs/Si regions down to the homoepitaxial GaAs level. Possible reasons for the improvement in the quality of near-surface GaAs layers are discussed. On the one hand, the presence of elastic deformations in the GaAs/LT-GaAs system led to dislocation line bending. On the other hand, gallium vacancies, formed in the LT-GaAs layers, diffused into the overlying GaAs layers and led to an increase in the dislocation glide rate. It was demonstrated that the GaAs/Si HSs obtained with these techniques are suitable for growing high-quality light-emitting HSs with self-assembled quantum dots.
本研究对低温（LT）GaAs层在GaAs/Si异质结构（HSs）中作为位错过滤器的应用进行了研究。研究了中间LT-GaAs层以及生长后和原位循环退火对GaAs/LT-GaAs/GaAs/Si(001) HSs结构性能的影响。结果发现，引入LT-GaAs层并结合生长后循环退火，可将穿透位错密度降低至5×10⁶ cm⁻²，GaAs表面的均方根粗糙度降低至1.1 nm，并将近表面GaAs/Si区域中非辐射复合中心的浓度降低至同质外延GaAs的水平。文中讨论了近表面GaAs层质量提高的可能原因。一方面，GaAs/LT-GaAs系统中弹性变形的存在导致位错线弯曲。另一方面，LT-GaAs层中形成的镓空位扩散到上覆的GaAs层中，导致位错滑移速率增加。结果表明，采用这些技术获得的GaAs/Si HSs适用于生长具有自组装量子点的高质量发光HSs。
