The B was introduced into Ge wafers by ion implantation, and the concentration profiles following furnace annealing were determined by using secondary ion mass spectroscopy. By fitting experimentally obtained profiles, the diffusion coefficient and solid solubility of B in Ge were calculated to be equal to 1.5 x 10-16cm2/s and 5.5 x 1018/cm3, respectively, at 850C. This value of the diffusion coefficient was at least 2 orders of magnitude lower than the lowest value reported in the literature. The results were considered to be significant because they questioned the general belief that vacancy diffusion was the mechanism responsible for the diffusion of B in Ge.

Diffusion of Ion-Implanted Boron in Germanium. S.Uppal, A.F.W.Willoughby, J.M.Bonar, A.G.R.Evans, N.E.B.Cowern, R.Morris, M.G.Dowsett: Journal of Applied Physics, 2001, 90[8], 4293-5