The relaxation mechanism in SiGe/Si(100) heterostructures which had been grown by means of solid-source molecular beam epitaxy was investigated. Samples of SiGe were grown which had Ge atomic concentrations that ranged from 0.035 to 0.34, and thicknesses that ranged from 32 to 475nm. Upon comparing unrelaxed samples which were grown at 350, 450 or 550C, and subjected to isochronal post-growth annealing, a higher dislocation density was found in samples which were grown at low temperatures. This peculiar behaviour was attributed to interactions, between point defects and dislocations, which promoted dislocation climb and reduced the activation energy for relaxation.

Structural Characterisation and Stability of SiGe/Si(100) Heterostructures Grown by Molecular Beam Epitaxy. M.Re, S.Scalese, S.Mirabella, A.Terrasi, F.Priolo, E.Rimini, M.Berti, A.Coati, A.Drigo, A.Carnera, D.De Salvador, C.Spinella, A.La Mantia: Journal of Crystal Growth, 2001, 227-228, 749-55