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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 × 106 cm−2, 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.

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GaAs nanowire (NW) self-catalyzed growth on GaAs (111) B and GaAs (100) substrates was carried out by molecular beam epitaxy. A mask for the self-catalyzed NW growth was created by oxidizing an epitaxial silicon layer grown on the GaAs surface by molecular beam epitaxy (MBE). Silicon oxidation was realized in an atmosphere of purified air under normal conditions without moving the structures out from the vacuum system volume of the molecular beam epitaxy chamber. The oxidation process of a silicon layer was studied using single-wave and spectral ellipsometry and the surface morphology of oxidized silicon was studied by atomic force microscopy. Substrates with NWs were studied by scanning electron microscopy. The NW density was demonstrated to be 2.6•107 cm-2 and 3•107 cm-2 for (111)B and (100), respectively.