Stress Effects on Defects and Dopant Diffusion in Si

Abstract

The effects of stress on equilibrium point defect populations and on dopant diffusion for single crystals free of extended defects are reviewed. The thermodynamic relationships presented permit the direct comparison of hydrostatic and biaxial stress experiments and of atomistic calculations under hydrostatic and nonhydrostatic stress for any proposed mechanism. Experiments on the effects of pressure and stress on the diffusivity are reviewed. For Sb in Si, using as input the measured effect of hydrostatic pressure on diffusion and the assumption of a pure vacancy mechanism, the measured effect of biaxial stress on diffusion can be predicted successfully with no free parameters. For B in Si, an apparent discrepancy between the hydrostatic and biaxial stress effects exists assuming a pure interstitial-based mechanism, The requirements to permit the prediction of the effect of an arbitrary stress state on diffusion in an arbitrary direction are discussed.