The segregation and interdiffusion of In atoms in GaAs/InAs/GaAs heterostructures were investigated by using secondary ion mass spectroscopy. When the InAs was grown in the layer-by-layer growth mode, with no dislocations, the segregation of In atoms became marked with increasing growth temperature. However, segregation was observed even at the relatively low growth temperature of 400C during molecular beam epitaxy. It was found that segregation was markedly enhanced by dislocations which were near to the hetero-interface when thick InAs layers were grown in a 3-dimensional island growth manner. Interdiffusion of In atoms towards the growth direction occurred after thermal annealing, and could be assisted by vacancies which propagated from the film surface and into the epilayer. It became apparent that interdiffusion was effectively suppressed by inserting a thin AlAs layer into the GaAs cap layer.

Segregation and Interdiffusion of In Atoms in GaAs/InAs/GaAs Heterostructures. T.Kawai, H.Yonezu, Y.Ogasawara, D.Saito, K.Pak: Journal of Applied Physics, 1993, 74[3], 1770-5