The diffusion of B into single crystals, from a BF2-implanted polycrystalline film deposited on the surface, was accurately modelled. The effective diffusivities of B in the monocrystalline substrate were extracted by using Boltzmann-Matano analyses, and the phenomenological model for B diffusivity was implemented in a computer simulation program. The model was applied to a range of furnace annealing conditions (800 to 950C, 0.5 to 6h) and BF2 doses ranging from 5 x 1015 to 2 x 1016/cm2 at 70keV. It was found that the diffusion parameters exhibited a complicated dependence upon the B composition (table 30).

A Physically Based Phenomenological Model using Boltzmann-Matano Analysis for Boron Diffusion from Polycrystalline Si into Single Crystal Si. A.Sultan, M.Lobo, S.Bhattacharya, S.Banerjee, S.Batra, M.Manning, C.Dennison: Journal of Electronic Materials, 1993, 22[9], 1129-36

Table 28

Diffusivity of B in Si