Effects of surface reconstruction on the epitaxial growth of III-Sb on GaAs using interfacial misfit array

Highlights: • Low-defected GaSb and InSb were grown on GaAs by MBE using interfacial misfit dislocations. • X-ray reciprocal space mapping can be used to characterize misfit dislocations at the III-Sb/GaAs interface. • Uniform interfacial misfit dislocation array were observed by TEM and x-ray RSM. • (2 × 8) pre-growth Sb reconstruction promoted the formation of 90° misfit dislocations at the III-Sb/GaAs interface. • The electron mobility in GaSb and InSb layers on GaAs can be enhanced through optimizing pre-growth Sb reconstruction. - Abstract: The effects of pre-growth Sb reconstruction on a GaAs surface on the epitaxial growth of III-Sb (GaSb and InSb) on a (100) GaAs substrate using interfacial misfit array were investigated. All samples exhibited smooth surface with a root mean square (r.m.s.) roughness below 1.5 nm and nearly 100% relaxation. Modeling indicated that the distribution and types of misfit dislocations can be evaluated using a reciprocal space map (RSM) of the x-ray measurements. The interfacial misfit (IMF) arrays in III-Sb/GaAs samples were characterized by RSMs of high-resolution x-ray diffraction (XRD) and transmission electron microscopy (TEM). The RSM results suggest that all samples exhibited highly uniformly distributed misfit dislocations, and pre-growth (2 × 8) Sb surface reconstruction promoted the formation of 90° dislocations in an IMF array. Hall measurements of unintentionally doped GaSb and InSb layers also suggested that the highest motilities at both 77 K and 300 K were achieved at the samples grown on GaAs with pre-growth (2 × 8) Sb reconstruction.