A model for mobility degradation in highly doped arsenic layers

As arsenic doping concentration increases past the electrical solubility limit, a significant fraction of the arsenic becoming electrically inactive. This inactive arsenic results in an electron mobility degradation. Using laser melt annealing and subsequent deactivation anneals, mobility was studied as a function of active and inactive dose. A model is presented for this effect based on the theory of scattering by neutral defects. Using the model, it is possible to extract active concentration profiles from resistive measurements.