Formation of interfacial misfit dislocation in GaSb/GaAs heteroepitaxy via anion exchange process

Abstract

We report the formation of interfacial misfit dislocation found in GaSb layers grown on (001) GaAs substrates using anion exchange process at different growth temperatures. An in-situ reflection high-energy electron diffraction (RHEED) in conjunction with transmission electron microscopy (TEM), atomic force spectroscopy (AFM) and X-ray diffraction (XRD) analysis was applied to investigate the relations between substrate temperature, As to Sb anion exchange, the changes in threading dislocation density and the growth kinetics of the GaSb/GaAs heteroepitaxy system. A GaSb layer grown at 450°C exhibited the lowest threading dislocation density. Our results provide further understanding of the dominant substrate temperature-dependent growth mechanisms that can affect threading dislocation in the GaSb on a GaAs heteroepitaxy system, which uses anion exchange process to facilitate the formation of interfacial misfit dislocation.