Substitutional-interstitial diffusion with bulk vacancy generation in semiconductors

A numerical technique is presented which gives a fairly complete description of the substitutional-interstitial diffusion mechanism. The mechanism is modelled directly on the computer without employing the differential equations which have been used by previous workers. Diffusion of the interstitial component of a diffusing impurity is taken into account together with self-diffusion by atoms of the host crystal and vacancy generation within the bulk of the crystal. The computed diffusion profiles compare well with experimental profiles found in certain semiconductor systems. The program is used to reproduce as closely as possible experimental diffusion profiles of silver in the III-V semiconductors GaAs and InP. The fitting parameters all represent physical quantities and the optimum values obtained are shown to be reasonable for the semiconductors concerned.