The diffusion of B from polycrystalline material into monocrystalline material was measured for B concentrations ranging from 1020 to 7 x 1020/cm3 by using secondary ion mass spectrometry. The B concentration on the monocrystalline side of the interface was independent of the diffusion time when either B-implanted or  in situ  doped polycrystalline material was used. The diffusivities found ranged from 4.2 x 10-14 to 9.0 x 10-14cm2/s.

Investigation of Boron Diffusion from Polycrystalline Silicon. B.Garben, W.A.Orr-Arienzo, R.F.Lever: Journal of the Electrochemical Society, 1986, 133[10], 2152-6