Nonequilibrium behavior of charged point defects during phosphorus diffusion in silicon

A new nonequilibrium kinetic model for phosphorus diffusion in silicon is presented. Concentrations of charged defects and defect-impurity pairs are determined explicitly by solving a system of quasilinear evolution equations, each of a drift-diffusion-reaction form with constant diffusivities. This formulation subsumes a hierarchy of models from the literature. Calculated profiles for a 10-min predeposition show both a tail and a well-defined kink plateau. The latter results directly from the kinetic model under the assumption of a strong bimolecular recombination.