Interfacial Structure in Highly Perfect InGaAs/InP Superlattices Grown by Gas-Source MBE: A High Resolution X-Ray Diffraction Study

High resolution X-ray diffraction (HRXRD) studies of GaInAs/InP superlattices reveal the presence of an intrinsic interfacial strain at heteroepitaxial interfaces. This strain is produced by an asymmetric ordering of the atomic layers in the leading and trailing interfaces of each quantum well as the result of the growth sequence during gas source molecular beam epitaxy (GSMBE). The presence of these thin strained regions was confirmed by using a kinematical diffraction model which assumes a series of altering wells and barriers with ideally sharp interfaces and which was extended to include a third and fourth layer on each side of the quantum well.