A study was made of molecular beam epitaxially grown samples which were -doped with Si and Al layers. Long-term diffusion annealing was carried out at temperatures ranging from 550 to 800C, and the concentration profiles were determined by means of secondary ion mass spectrometry. It was found that the results could be described by the expression,

D(cm2/s) = 7.9 exp[-2.25(eV)/kT]

The Si diffusion coefficients which were obtained were in good agreement with data which had been obtained by using rapid thermal annealing, capacitance-voltage profiling, and sandwiched diffusion sources. They differed from earlier measurements which had been based upon the diffusion of implanted dopants that were much more widely spread. It was concluded that the more accurate data which resulted from -doping showed that the diffusion coefficient was an intrinsic parameter, provided that the amount of dopant and the dislocation density were kept sufficiently small.

F.Bénière, R.Chaplain, M.Gauneau, V.Reddy, A.Régrény: Journal de Physique III, 1993, 3[12], 2165-71