GAS-SOURCE MOLECULAR-BEAM EPITAXY MIGRATION-ENHANCED EPITAXY GROWTH OF INAS/ALSB SUPERLATTICES

We report on the gas source molecular beam epitaxy/migration enhanced epitaxy (MEE) growth of InAs/AlSb superlattices. The incorporation behavior of constituent group III and group V atoms during growth is investigated in detail using reflection high energy electron diffraction. In and Sb atoms are found to move towards the surface during MEE growth, although the movement of In atoms can be reduced by lowering the growth temperature. Raman scattering measurement of InAs/AlSb superlattices shows that the formation of atomically controlled heterointerfaces (InSb- or AlAs-type interfaces in InAs/AlSb superlattices) is difficult. However, photoluminescence (PL) measurement shows that the optical properties of quantum well structures are strongly dependent on the shutter sequence at the interfaces. 77 K PL from InAs/AlSb quantum well structures with an InSb-type interface shutter sequence is one order of magnitude stronger than that of the AlAs-type interface.