Dopant diffusion during high-temperature oxidation of silicon

In order to test models of oxidation enhanced diffusion, we measure phosphorus diffusion in 〈100〉 silicon at high temperature (1150 °C) under both oxidizing and nonoxidizing conditions in ambients containing dry O2 diluted with N2. We find enhanced diffusion even at extremely low rates in contrast to observations in 〈111〉 material. Based on the observations for both 〈100〉 and 〈111〉 material, we evaluate proposed models for interstitial concentration during oxidation.