MBE growth of In0.53Ga0.47Sb on In0.53Ga0.47As/InP substrates using the interfacial misfit dislocation arrays

Abstract

We present the growth of highly relaxed In0.53Ga0.47Sb buffers on In0.53Ga0.47As/InP by inducing a periodic array of interfacial misfit dislocation arrays at the In0.53Ga0.47Sb/ In0.53Ga0.47As interface. The periodic 90° misfit dislocation array is realized through As for Sb anion exchange while keeping the group III sublattice the same. Transmission electron microscopy (TEM) results show the presence of misfit dislocations with a periodicity of 6.16 nm, which corresponds to 14 In0.53Ga0.47Sb lattice sites or 15 In0.53Ga0.47As lattice sites. The In0.53Ga0.47Sb epilayer, however, is affected by phase segregation as evidenced by both TEM and Nomarski optical phase microscopy. The x ray based reciprocal space mapping indicates relaxation to be 99.5% for the In0.53Ga0.47Sb epilayer.