Anomalous energetics and defect-assisted diffusion of Ga in silicon

MELIS, CLAUDIO;LOPEZ, GIORGIA MARIA;FIORENTINI, VINCENZO

2004-01-01

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Abstract

We study via first-principles calculations the energetics and diffusion of Ga in c-Si. In contrast to B and In, the favored Ga/self-interstitial complex is the tetrahedral interstitial Ga-T. Thus in the presence of self-interstitials Ga becomes interstitial, and is electrically deactivated as an acceptor. Studying the native-defect assisted diffusion, we find a self-interstitial-assisted mechanism to be favored; vacancy-assisted diffusion has a sizably larger activation energy, in agreement with the observed transient enhanced diffusion behavior. (C) 2004 American Institute of Physics.