Quantum wells were grown at 525C by means of ultra high-vacuum chemical vapor deposition. Changes in the photoluminescence line energies were monitored, and the extent of interdiffusion in the wells during annealing was calculated. A strong initial enhancement of the diffusivity was observed in as-grown material. Samples which were annealed by using a 2-step process, in which the strains and Ge peak concentrations were unchanged during a first low-temperature step, exhibited much less interdiffusion during the second step. It was suggested that strain alone could not explain the enhanced interdiffusion, which was instead attributed to the effect of grown-in non-equilibrium point defects.

H.Lafontaine, D.C.Houghton, N.L.Rowell, G.C.Aers: Applied Physics Letters, 1996, 69[10], 1444-6