Growth and Characterization of InSb Thin Films on GaAs (001) without Any Buffer Layers by MBE

We report the growth of InSb layers directly on GaAs (001) substrates without any buffer layers by molecular beam epitaxy (MBE). Influences of growth temperature and V/III flux ratios on the crystal quality, the surface morphology and the electrical properties of InSb thin films are investigated. The InSb samples with room-temperature mobility of 44600 cm^2/Vs are grown under optimized growth conditions. The effect of defects in InSb epitaxial on the electrical properties is researched, and we infer that the formation of In vacancy (V_\rm In) and Sb anti-site (Sb_\rm In) defects is the main reason for concentrations changing with growth temperature and Sb_2/In flux ratios. The mobility of the InSb sample as a function of temperature ranging from 90 K to 360 K is demonstrated and the dislocation scattering mechanism and phonon scattering mechanism are discussed.