Atomistic models of vacancy-mediated dopant diffusion in silicon at high doping levels

This paper uses Monte-Carlo simulation on the silicon lattice to investigate vacancy-mediated dopant diffusion. By considering vacancy/dopant interaction potentials which extend out to third-nearest-neighbor distances as required for pair diffusion theories, we observe the very rapid increase in dopant diffusivity at concentrations above 2×10²⁰ cm^-3 that has been observed experimentally for group IV and V atoms in silicon. We also derive an improved analytic expression for dopant diffusivity at low and moderate doping levels as a function of interaction potential that agrees with the simulation results. Further simulations verify the central role of third-nearest-neighbor interactions to vacancy-mediated diffusion in silicon