It was noted that undoped superlattices which had been grown at low temperatures underwent marked interface intermixing upon increasing the annealing temperature up to 900C. Quantum confinement shifts which were caused by the intermixing of low-temperature re-grown and normal superlattices were studied by using electro-modulation spectroscopy. The effective activation energy for intermixing in the low-temperature superlattices during isochronal post-growth annealing (30s) was found to be 0.32eV. This value was anomalously lower than that for superlattices that were grown at normal temperatures. Roughening of the interfaces, due to As precipitates, was associated with the intermixing.

I.Lahiri, D.D.Nolte, J.C.P.Chang, J.M.Woodall, M.R.Melloch: Applied Physics Letters, 1995, 67[9], 1244-6