First-principles pseudopotential calculations of dopant-vacancy exchange barriers indicated a strong dependency upon dopant valence and atomic size, in contrast to current models for vacancy-mediated dopant diffusion. These first-row elements were found to have exchange barriers which were an order of magnitude larger than the assumed value of 0.3eV (the Si-vacancy migration energy).

Valence and Atomic-Size Dependent Exchange Barriers in Vacancy-Mediated Dopant Diffusion. J.S.Nelson, P.A.Schultz, A.F.Wright: Applied Physics Letters, 1998, 73[2], 247-9