The diffusion of Ni in P-doped Czochralski monocrystals was studied by using a 63Ni radiotracer, autoradiographic, and sectioning techniques. It was found that the data for temperatures of between 220 and 540C, were described by:

D(cm2/s) = 6 x 10-4exp[-0.76(eV)/kT]

The data supported an interstitial diffusion mechanism, with no participation of native Si defects. The solubility of Ni at 800C was of the order of 1016/cm3. At low temperatures, the solubility was unclear due to experimental limitations. An analysis of previous results for Ni diffusion revealed a scatter of 10 orders of magnitude. It was suggested that studies which involved low diffusion coefficients and large activation energies were dubious, due to problems which were associated with surface conditions and with the limits of Ni detection. The latter arose from the rapid diffusion and low solubility of Ni.

Diffusivity and Solubility of Ni (63Ni) in Monocrystalline Si. F.H.M.Spit, D.Gupta, K.N.Tu: Physical Review B, 1989, 39[2], 1255-60