Epitaxial and interface properties of InAs/InGaSb multilayered structures

Abstract

We have used the technique of molecular beam epitaxy to grow InAs on GaSb, GaSb on InAs, and InAs/InxGa1−xSb (0≤x≤0.4) multilayered structures and have performed a detailed investigation of the layers and resultant interfaces. The structures were grown on (100) oriented GaSb or GaAs substrates. Combined reflection high energy electron diffraction, x-ray photoelectron spectroscopy (XPS), and Auger electron spectroscopy (AES) studies indicate that Sb is persistently present on the InAs growth surface. XPS and AES analysis of InAs/GaSb heterojunctions indicates no compound formation at either the InAs/GaSb or GaSb/InAs interface. Secondary ion mass spectroscopy (SIMS) and XPS extinction profiles reveal the presence of approximately 5–10% As in the nominally pure GaSb layers. Analysis of InAs/GaSb/GaSb (100) structures by SIMS indicates that the As is incorporated during growth. The multilayer structures have been characterized by double crystal x-ray diffraction and the data has been modeled using kinematic formulations. We find that the experimental data is fitted by assuming atomically abrupt composition changes across the interfaces.