Growth and characterization of InGaAs/InAlAs in-plane superlattices on (110) InP

We studied the surface steps during growth on misoriented (110) InP substrates, and grew InGaAs/InAlAs in-plane superlattices (IPSLs) using molecular beam epitaxy. The surface steps were evaluated by reflection high energy electron diffraction and atomic force microscopy (AFM). We found that two types of surface steps (single and double monolayer steps) were arranged depending on the growth conditions. Step edges of both types were seen to be little undulated in the AFM images. For the IPSL growth, we alternately grew half monolayers of AlAs and GaAs and single monolayers of InAs, keeping the regular arrays of single monolayer steps. The structural studies of IPSLs using transmission electron microscopy and photoluminescence measurements indicated InGaAs/InAlAs IPSLs composed of InAs/GaAs and InAs/AlAs monolayer superlattices were grown with some evidences of disordering. We also grew InAs/GaAs in-plane strained superlattices with the periodicity of about 8 nm on the misoriented (110) InP substrates