Abstract :
The standard theory of dopant diffusion in semiconductors based on the reaction–diffusion equations is generalized to include ‘many body effects’ due to the presence of a very high concentration of immobile dopants. This new formulation makes it possible to calculate the concentration profiles of donors/acceptors, clusters, and precipitates, if any, both in silicon and semiconducting compounds in good agreement with the experiment. Moreover, it is possible to calculate the effective diffusion coefficient within the steady-state approximation. This approach has been used to calculate the explicit form of the effective diffusion coefficient in predoped semiconductors. Furthermore, simple analytical formulae are given for, respectively, dopant in-diffusion profiles and the maximum penetration depth.
