It was pointed out that one of the potential advantages of rapid thermal  annealing, as compared with conventional furnace annealing, was a reduced implanted dopant and background impurity diffusion. Here, the migration of Cr during the annealing of Cr-doped semi-insulating material implanted with 100keV Si+ ions to a dose of 7 x 1012/cm2 was measured using secondary ion mass spectrometry. Un-capped rapid thermal annealing (860 or 930C, 1 to 60s) was investigated and its effect was compared with that of capless furnace annealing (0.5h). It was deduced that, during rapid thermal annealing, Cr migration was marked and exhibited a strong time-temperature dependence.

Substrate Impurity Migration during Rapid Thermal Annealing of Si Implanted GaAs. H.Kanber, J.M.Whelan: Journal of the Electrochemical Society, 1987, 134[10], 2596-9