Molecular beam epitaxy of InSb (110)

Abstract

Molecular beam homoepitaxy of InSb on the nonpolar (110) face is reported for the first time. Growth conditions and substrate preparation techniques are discussed. With an In beam flux of 3×1014 at./cm2 s a growth rate of 0.72 μm/h is obtained, hence the sticking coefficient of In on InSb (110) is one. Layers of good crystalline quality and of stoichiometric composition were grown at a substrate temperature of 380 °C and a flux ratio ΦSb/ΦIn=3. The ΦSb/ΦIn vs Ts diagram is given. Two surface reconstructions are reported: the well-known (1×1) at high Ts and a new reconstruction with (1×4) symmetry at lower Ts. The latter may be connected with InSb bond breaking or an In overlayer. The epilayers with thicknesses from 1 to 7.7 μm all show n-type conductance with mobilities from 1.2 to 7.5 m2/V s at 77 K. By optimizing the growth conditions with respect to the electrical transport properties much higher values should be attainable.