Anion control in molecular beam epitaxy of mixed As/Sb III-V heterostructures

Superlattices consisting of As monolayers (MLs) in (In,Ga,Al)Sb and Sb MLs in (In,Ga,Al)As were grown by molecular beam epitaxy and characterized by x-ray diffraction, Raman spectroscopy, and high-resolution transmission electron microscopy. In all cases, well-defined superlattices were formed when the growth temperature was sufficiently low. As temperature increases for the As MLs in antimonides, substantial intermixing occurs. For Sb MLs in arsenides, Sb evaporation from the surface increases with increasing growth temperature. These results are discussed in the context of device heterostructures containing InAs/GaSb and InAs/AlSb heterojunctions.