A GETTERING SIMULATOR: POLISHED WAFERS AND p/p~(++) EPILAYERS

摘要

We use standard solubility relations and diffusion-limited rate equations to create a continuum model for the gettering of Fe in silicon. The model employs experimentally determined values for diffusivity, ion-pairing binding potentials and precipitate densities. The goal is to evaluate the relative effectiveness of solubility enhancement, internal gettering (IG) precipitation and backside gettering outdiffusion. The materials variables are p-type doping level, density of bulk IG sites and backside IG site density. We follow the contaminant concentration at arbitrary positions in the wafer as a function of time and temperature. The simulator can be used for the design of wafer defect engineering and heat treatments for optimized gettering processes.