PNNL

Abstract

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