Self-diffusion was studied by using epitaxially grown isotopically enriched structures, with non-equilibrium concentrations of native point defects, that were created by thermal oxidation and nitridation. A comparison with P and Sb diffusion provided evidence for a dual vacancy-interstitial self-diffusion mechanism; perhaps with a small substitutional exchange component. It was determined that, at 800 to 1100C, the interstitial-mediated fraction of self-diffusion was limited to between 0.50 and 0.62. The corresponding activation enthalpies were 4.68 and 4.86eV for the interstitial and vacancy mechanisms, respectively. Both mechanisms exhibited high activation entropies. This represented direct experimental evidence of the marked similarity between the energetics of these native point defects.

Non-Equilibrium Experiments on Self-Diffusion in Silicon at Low Temperatures using Isotopically Enriched Structures A.Ural, P.B.Griffin, J.D.Plummer: Physica B, 1999, 273-274, 512-5