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

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 1.5nm 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 77K and 300K were achieved at the samples grown on GaAs with pre-growth (2×8) Sb reconstruction.