Random dopant model for three-dimensional drift-diffusion simulations in metal-oxide-semiconductor field-effect-transistors

We investigate the dopant model employed in drift-diffusion device simulati ons for the study of statistical threshold voltage variations associated wi th discrete random dopants. It is pointed out that the conventional dopant model, when extended to the extreme "atomistic" regime, becomes physically inconsistent with the length-scale presumed in drift-diffusion simulations. Splitting the Coulomb potential of localized dopants between the long-rang e and short-range parts, we propose a dopant model appropriate for three-di mensional drift-diffusion simulations. (C) 2001 American Institute of Physi cs.