Simulation of metallic impurity gettering in silicon by MeV ion implantation

Abstract

A simple model for metallic impurity gettering by buried layers created by MeV ion implantation in silicon is presented. For our experimental conditions, the precipitation of supersaturated Fe at dislocation loops in silicon is not diffusion limited. Furthermore, a non-zero silicide-matrix interfacial energy density was required to fit our experimental data. In samples containing dislocations and boron-implanted layers, the dislocations trap more Fe than the boron, but the latter is more effective at reducing the concentration of ungettered Fe. Although we were able to simulate impurity distributions fairly well in many cases, the model is not free from adjustable parameters due to a lack of knowledge of detailed impurity–defect interactions and the silicide-matrix interfacial energy density.