Defect-coupled diffusion at high concentrations

The role of point defects during silicon dopant diffusion at high dopant concentrations is considered. Starting from the basic reaction equations for the formation of dopant-defect pairs, the effective dopant diffusivity is derived. Consideration of these equations shows why a concentration-dependent diffusivity model is often sufficient for modeling diffusion. Consideration of these equations also shows the effect of processes such as oxidation, which inject defects at the surface. Analysis of oxidation-enhanced diffusivity experiments under extrinsic conditions allows the silicon self-interstitial energy levels to be extracted directly at diffusion temperatures.<>