The vacancy in silicon: A critical evaluation of experimental and theoretical results

Recent experimental studies of Shimizu [Phys. Rev. Lett. 98, 095901 (2007)] revealed an activation enthalpy of 3.6 eV for the vacancy contribution to Si self-diffusion. Although this value seems to be in accurate agreement with recent theoretical results, it is at variance with experiments on vacancy-mediated dopant diffusion in Si. In the present study we review results from electronic structure calculations and conclude that the calculations are consistent with an activation enthalpy of 4.5-4.6 eV rather than 3.6 eV for the vacancy contribution to self-diffusion. Moreover, our calculations predict activation enthalpies of 4.45 and 3.81 eV for the vacancy-mediated diffusion of phosphorus and antimony, respectively, in good agreement with the most recent experimental results. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.2996284]