MATHEMATICAL MODELLING OF THE DIFFUSION-INDUCED DISORDERING OF A SEMICONDUCTOR SUPERLATTICE

This paper is concerned with superlattice disordering. We use a mathematical model to describe the enhancement of semiconductor self-diffusion by an impurity. The model we develop is based on the kick-out mechanism and we assume that both the impurity and the host diffuse by this process. By using the method of multiple scales, we separate the behaviour of the system into two distinct length scales. This leaves two reduced problems to be solved, one describing the impurity diffusion and the other describing the intermixing. Results are given and a comparison made between the asymptotic results and those obtained by directly solving the problem numerically.