High-resolution electron microscopy and X-ray diffraction characterization of alternately strained (GaAs)n(GaP)m(GaAs)n(InP)m superlattices grown by Atomic Layer Molecular Beam Epitaxy.

Abstract

Alternately-strained-layer of (GaAs)n(GaP)m(GaAs)n(InP)m, superlattices with n = 10, 90 and m = 2 monolayers, have been characterized by X-ray diffraction and high-resolution transmission electron microscopy. The heterostructures were grown by atomic layer molecular beam epitaxy on GaAs semi-insulating substrates at a substrate temperature of 710K. All the structures were coherent with the substrate and there is an effective compensation of the strains due to GaP and InP layers. X-ray diffraction and high-resolution electron microscopy analysis indicate a high crystalline quality with layers thickness deviations of ± 1 monolayer from the designed value.