Quantitative measurement of the surface silicon interstitial boundary condition and silicon interstitial injection into silicon during oxidation

During the oxidation of silicon, interstitials are generated at the oxidizing surface and diffuse into the silicon. Boron diffusion was used to map the local interstitial supersaturation, the ratio of interstitial concentration to the equilibrium concentration of interstitials versus the distance above buried (formula presented) layers during oxidation. The average interstitial supersaturation at the silicon surface, extrapolated from the depth profiles was ∼25 and ∼13 for 750 °C and 850 °C, respectively. Using the measured interstitial concentration at the surface, the silicon interstitial injection into the silicon is calculated for oxidation at 750 °C and 850 °C. Finally, it is found that the surface boundary condition remains relatively fixed for an interstitial injection rate ranging over four orders of magnitude.