Impurity redistribution during 2-step p-type diffusion was investigated. A theoretical model was formulated, from which a closed-form expression for the impurity profile was derived. It was deduced that the observations could be described by:

D (cm2/s) = 3.2 x 10-2 exp[-3.01(eV)/kT]

J.S.T.Huang, L.C.Welliver: Journal of the Electrochemical Society, 1970, 117[12], 1577-80