Initial stage of InSb heteroepitaxial growth on GaAs (111)A: effect of thin InAs interlayers

Abstract

Molecular-beam epitaxy of InSb on the (111)A-oriented GaAs substrates has been studied using electron diffraction, x-ray diffraction, and scanning probe microscopy. The direct heteroepitaxialgrowth of InSb on GaAs(111)A results in a cracked morphology with flat terraces and deep gaps, which could be attributed to the extremely large lattice mismatch between InSb and GaAs (14.6 %). When thin (5 – 30 monolayer thickness) InAs films are used as interlayers, more continuous and flat InSb films are obtained. The proposed growth technique using (111)A-oriented GaAs substrates and thin InAs interlayers are effective in improving the surface morphology and the structural quality of InSb films in highly lattice-mismatched systems.