Growth of InAs0.32Sb0.68 on GaAs using a thin GaInSb buffer and strain superlattice layers

摘要

We report on the growth of an InAs 0.32 Sb 0.68 layer on (001) GaAs substrates. The lattice mismatch strain between the InAs 0.32 Sb 0.68 layer and the GaAs substrate was accommodated using a thin 50–100?nm Ga 0.35 In 0.65 Sb buffer with interfacial misfit (IMF) dislocations. The epitaxial structures were characterized using transmission electron microscopy and x-ray diffraction analysis. The threading dislocation density in the InAs 0.32 Sb 0.68 layer was reduced successfully to ～1 × 10 8 ?cm ?2 using the combination of a Ga 0.35 In 0.65 Sb IMF buffer and InSb/Ga 0.35 In 0.65 Sb superlattice layers. Compared to GaSb/GaAs and InSb/GaAs interfaces, a significantly higher threading dislocation density (10 11 ?cm ?2 ) was observed at the Ga 0.35 In 0.65 Sb/GaAs interface. Detailed analysis suggests that high threading dislocation density in the Ga 0.35 In 0.65 Sb IMF buffer could be due to the non-uniform microscopic distribution of indium and gallium atoms. This work is beneficial to the scientific community in the growth of the InAs 0.32 Sb 0.68 material as it provides a novel approach to prepare a platform for the growth of the InAs 0.32 Sb 0.68 material, which does not have a suitable lattice-matched substrate, on the widely available GaAs substrate.