Theory of enhanced diffusion in predoped and implanted silicon

A new physical model is utilized in computer simulations to calculate dopant diffusion profiles in silicon. It is based on a system of reaction-diffusion equations taking into account all the defects involved and their interaction; moreover, at high concentrations the predominant influence of the limited dopant solubility is included. This makes it possible to interpret both the enhanced transient and the steady-state dopant diffusion phenomena and to calculate the effective diffusion coefficient.