Published online by Cambridge University Press: 28 February 2011
Carbon diffusivity is reported for different ambient conditions imposed during annealing of silicon in the temperature range from 800 to 100°C, which produce varying levels of silicon self-interstitial supersaturation. The diffusivities are deduced from SIMS analysis of carbon out-diffusion profiles. Carbon diffusivity is increased by up to a factor of 70 in annealing with phosphorus in-diffusion, and by a factor of as much as seven in an oxidizing ambient, when compared to anneals in a nitrogen ambient. The enhancements tend to decrease above 11000C. This behavior can be explained by attributing the increase in carbon diffusivity to self-interstitial supersaturation which increases the concentration of highly mobile carbon selfinterstitial pairs. Significant time dependent effects were also observed for 800 and 9000C phosphorus in-diffusion conditions.