The Si migration and impurity-induced layer intermixing from a buried impurity source were studied by means of transmission electron microscopic and secondary ion mass spectroscopic studies of isolated Si-doped GaAs layers in an undoped Ga0.6Al0.4As/GaAs superlattice, and by photoluminescence measurements of Si-doped quantum wells with undoped Ga0.6Al0.4As barriers. In annealed samples, the Si profiles suggested the occurrence of a Si diffusion process which involved multiply ionized column-III vacancies. The width of the resultant Si profile, and the spatial extent and completeness of intermixing, depended strongly upon the initial Si concentration in the doped layer.

K.J.Beernink, R.L.Thornton, G.B.Anderson, M.A.Emanuel: Applied Physics Letters, 1995, 66[19], 2522-4