A new model for impurity diffusion via a point defect plus impurity pair mechanism was developed. A pair of coupled non-linear partial differential equations for the Si self-interstitial and the impurity was derived and solved numerically. The usual kink and tail of P and, to some extent, the B diffusion profiles arose naturally from the solution. The coupling between defect and impurity became smaller at high temperatures and at low impurity concentrations; in agreement with experimental observations.

B.J.Mulvaney, W.B.Richardson: Applied Physics Letters, 1987, 51[18], 1439-41