Molecular dynamics simulation of annealing of post-ballistic cascade remnants in silicon

A molecular dynamics simulation of the long-term annealing of collision cascade remnants in silicon is reported. The aim of the study is to determine how many point defects in freely-migrating and clustered form remain in the cascade region after the complete recrystallization of cascade-generated amorphous zones and the recombination of close-lying mobile defects. Representative damage patterns created by self-ion recoils in the energy range of 0.5–5 keV are used as the starting configurations. The simulation shows a strong difference in the clusterization level of vacancies and interstitials after the long term annealing, suggesting explanation for some not yet clearly understood features of radiation damage accumulation in silicon. An overall low ultimate level of damage generation in cascades (∼5 surviving interstitial–vacancy pairs per keV of initial recoil energy) is predicted.