Determination of silicon point defect properties from oxidation enhanced diffusion of buried layers

Abstract

In order to characterize fundamental silicon point defect properties, the enhanced diffusion of phosphorous buried layers as a function of depth into the silicon substrate was measured during interstitial injection via thermal oxidation of the wafer surface. The measurements were used to calculate the effective interstitial diffusivity in epitaxial silicon at 1100 °C. The experimental results were also interpreted using a physical model which includes bulk recombination of interstitials with vacancies and a fast interstitial diffusivity calculated from metal gettering. The model effectively accounted for the experimental data, and through comparison of the data with model simulations, the ratio of the concentrations of vacancies and interstitials in equilibrium was obtained.