Role of impact ionization and self-consistent tunnel injection in Schottky-barrier diodes operating under strong reverse-bias conditions

This work shows that for a correct analysis of Schottky barrier diodes operating under strong reverse-bias conditions, it is necessary to account for the self-consistency between the shape of the energy barrier and carrier concentration in the depletion region since the full-depletion approximation fails to estimate the current. This happens for very high applied voltages, at which impact ionization by electrons and holes must also be considered. Two example GaN diodes with different doping concentrations and barrier heights are analyzed. The results are relevant to regions of the diodes where a very high tunnel injection takes place, like the contact edge or surface inhomogeneities.