First-principles total-energy calculations that clarified the mechanisms of B diffusion in SiO2 were reported. It was found that a B atom took a variety of stable and metastable geometries depending upon its charge state. It was also found that the atomic rearrangements during diffusion revealed a wealth of feasible bonding in SiO2, and that the calculated activation energy agreed with available experimental data. Recombination-enhanced diffusion was also proposed.

Mechanisms of Diffusion of Boron Impurities in SiO2. M.Otani, K.Shiraishi, A.Oshiyama: Physical Review Letters, 2003, 90[7], 075901 (4pp)