Defect clustering during ion irradiation of GaAs: Insight from molecular dynamics simulations

Defect formation in compound semiconductors such as GaAs under ion irradiation is not as well understood as in Si and Ge. We show how a combination of ion range calculations and molecular dynamics computer simulations can be used to predict the atomic-level damage structures produced by MeV ions. The results show that the majority of damage produced in GaAs both by low-energy self-recoils and 6 MeV He ions is in clusters, and that a clear majority of the isolated defects are interstitials. Implications of the results for suggested applications are also discussed.