- Taylor, W.J. and Tan, T.Y. and Gosele, U.M., Correlation of strain and self-interstitial supersaturation during oxygen precipitation in silicon,
Proceedings of the Second Symposium on Defects in Silicon. Defects in Silicon II
pp. 255 - 62 .
(last updated on 2007/04/10)
The authors address the concept of strain energy inherent in SiO2 formation in silicon by a careful accounting of atomic volumes during precipitation. They allow the precipitate to release excess strain by ejecting silicon self-interstitials from the adjacent matrix. In contrast to some previous models, the self-interstitials are treated as an independent variable in the total free energy equation. By minimizing the free energy with respect to both oxygen and self-interstitials, they obtain two relationships: (a) a direct correlation between strain and self-interstitial supersaturation, and (b) an expression for the critical radius which is much more versatile than that commonly used. Next, the introduce a new concept to the dynamics of precipitation: a flux balance between the oxygen and self-interstitials. This provides a means of quantifying self-interstitial supersaturations during precipitation, and allows for calculation of the strains involved. Finally, they show how these self-interstitial supersaturations can affect oxygen fluxes and precipitate growth rates
elemental semiconductors;free energy;internal stresses;interstitials;oxygen;precipitation;silicon;