Generation of Frenkel defects in heavily arsenic doped silicon: A first-principles study

The generation of Frenkel defects (a self-interstitial and a vacancy) in heavily As doped Si is investigated theoretically based on first-principles total energy calculations. We find that it is much easier to generate a self-interstitial and a vacancy close to substitutional As atoms than in pure Si, due to the lower energy cost. The As atom binds strongly with the vacancy, but does not bind with Si self-interstitial and other As atoms. We have considered several different reactions such as Si5→Si4V+I, AsSi4→AsSi3V+I, As2Si3→As2Si2V+I, As3Si2→As3SiV+I, and As4Si→As4V+I. The theoretical results are in good agreement with experimental observations. (c) 2000 American Institute of Physics