Donor deactivation at high doping limit: Donor pair and impurity band model

We present a donor deactivation model at high doping limit. The limitation of the existing activation model is discussed and a solution is proposed. In the new model, the impurity band model is combined with ab-initio based lattice Monte Carlo (LMC) simulation to explain the saturation behavior of active donor concentration experimentally observed. The developed impurity band model can reproduce the activation level correctly and improves our understanding of charge carrier distribution in the impurity band. It also provides a new aspect of the behavior of the Fermi level (E_F) at high doping limit. As a result, incorporating the new models into the existing diffusion and activation model improves the predictability of donor activation level.