High-resolution x-ray diffraction study of InAs-GaAs superlattices grown by molecular-beam epitaxy at low temperature

InAs-GaAs superlattices grown by molecular-beam epitaxy at low temperature are investigated by high-resolution x-ray diffractometry. It is shown that despite a very high density of point defects due to the presence of excess arsenic, the as-grown superlattice has high crystal perfection. An analysis of the changes in the x-ray diffraction curves shows that high-temperature annealing, which is accompanied by the formation of As clusters and diffusion of indium, produces significant structural transformations in the GaAs matrix and at the interfaces. (C) 1998 American Institute of Physics.