Effect of InAs Thickness on the Structural and the Electrical Properties of InAs Layers Grown on GaAs Substrates with an AlAs0.32Sb0.68 Buffer Layer

Abstract

InAs layers on GaAs substrates with AlAs0.32Sb0.68 buffer layers were grown by using molecular beam epitaxy. X-ray diffraction patterns showed that the dominant peaks corresponding to the GaAs, InAs, and AlAs0.32Sb0.68 layers appeared. Atomic force microscopy images showed that the root-mean-square surface roughness of the InAs surface increased with increasing thickness of the InAs layer due to the lattice-constant difference between the InAs and the AlAs0.32Sb0.68 layers, resulting in relaxation of the strain in the InAs layer. Hall effect measurements at 300 K showed that the electron mobility increased with increasing InAs film thickness.