The effects of strain on dopant diffusion in silicon

A point defect based model for the stress effects on dopant diffusion is presented. Binding energies and diffusivities of dopant-defect pairs under pressure are modeled and encapsulated into diffusion equations. Boron segregation around dislocation loops in silicon is explained by the pressure effects, and the simulation agrees with the measured data. Two-dimensional simulation of diffusion in the pressure field leads to better prediction of threshold voltage shift in short channel LDD MOS transistors. The model also shows that retarded diffusion of phosphorus under oxide-padded nitride film of various widths is caused by the stress at the film edge.<
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