The time evolution of interdiffusion in multiple quantum wells: a new model of impurity-induced compositional intermixing

A new model for impurity-induced compositional interdiffusion which depends explicitly on the time evolution of the impurity-induced vacancy spatial profile is explored. The inclusion of a new phenomenological term depending on the time derivative of the vacancy spatial profile provides a time scale, as well as a depth profile of the resulting interdiffusion. Calculations are presented as a function of time for a variety of vacancy concentrations and contrasted to the calculations using the model of Kahen, Rajeswaren, and Lee. Our model generates good agreement with a range of experiments including Si-focused ion beam implantation experiments in AlGaAs multiple quantum wells.