Molecular dynamics simulation of intrinsic point defects in germanium

Results are presented of the calculations of thermodynamic properties of intrinsic point defects in germanium. The results are based on molecular dynamics calculations using the Stillinger and Weber potential and on the Einstein diffusion equation. The obtained formation and migration energies of the neutral vacancy, as well as the formation energy of the self-interstitial, are in good agreement with other recent calculations results. It is also shown that the calculated formation energy of the neutral vacancy is in good agreement with the experimental values obtained from quenching experiments, taking into account the equilibrium theory in pure elemental crystals. Finally, molecular dynamics simulations of the relaxation of a spherical vacancy cluster in germanium predicted a truncated octahedral equilibrium shape, similar to the observed surface pit shape on polished germanium wafers. (C) 2007 Elsevier B.V. All rights reserved.