Molecular beam epitaxial growth of AlGaAs/InGaAs/GaAs planar superlattice structures on vicinal (111)B GaAs and their transport properties

AlGaAs/InGaAs/GaAs planar superlattice structures have been formed by depositing a very thin InGaAs layer onto vicinal (111)B GaAs surfaces, where the bunching of atomic steps has resulted in a corrugation of about 20-30 nm in period and 2 nm in height. The growth condition to form bunched steps with little irregularity is clarified. By selectively doping, electrons are introduced into such planar superlattices, and their transport parallel to and normal to the steps are studied. Clear Shubnikov-de Haas oscillations with specific features and quantized Hall plateaus are observed in both geometries, suggesting that electrons retain some of their quasi-two-dimensional characters. In-plane anisotropies of electron mobilities are studied, and discussed in terms of electron scatterings by step structures. Photoluminescence spectra are studied to evaluate the in-plane potential modulation and its inhomogeneities.(c) 2005 American Vacuum Society.