A comprehensive study of the migration of di- and tri-interstitials in Si was performed using classical molecular dynamics simulations with the Stillinger–Weber potential. The initial di- and tri-interstitial configurations with the lowest formation energies were determined, and then, the defect migration was investigated at between 800 and 1600K. The defect diffusivity and the self-diffusion coefficient per defect were calculated. Compared to the mono-interstitial, the di-interstitial migrates faster, whereas the tri-interstitial diffused slower. The migration mechanism of the di-interstitial showed a pronounced dependence on the temperature. Like in the case of the mono-interstitial, the mobility of the di-interstitial was higher than the mobility of the lattice atoms during the defect diffusion. On the other hand, the tri-interstitial mobility was lower than the corresponding atomic mobility. The implications of the present results for the analysis of experimental data on defect evolution and migration were considered.

Migration of Di- and Tri-Interstitials in Silicon. M.Posselt, F.Gao, D.Zwicker: Nuclear Instruments and Methods in Physics Research Section B, 2005, 228[1-4], 212-7