Structural characterization of interfaces in the AlxGa1−x As/GaAs/AlxGa1−x As heterostructures by high-resolution X-ray reflectometry and diffractometry

Abstract

The structural properties of multiplayer AlxGa1−xAs/GaAs/AlxGa1−xAs systems (x ≈ 0.2) grown on GaAs(001) substrates are studied by the methods of double-crystal X-ray diffractometry and reflectometry. The depth profiles of deformation, amorphization, and density of the layers are obtained. It is shown that despite small differences (5–7%) in the densities of the AlxGa1−xAs layers and the substrate and the small thickness of the AlAs layer (1–2 nm) separating the GaAs quantum well, it is possible to reconstruct the heterostructure model by the method of X-ray reflectometry and to determine the thickness of the transitional layers at a resolution of 0.1–0.2 nm. It is also established that the reflectometry data obtained complement the X-ray diffraction data considerably and allow one to estimate the roughness and the character of the aluminum distribution at the interfaces.