Study of grain boundaries influence on electrical properties of nitrides

The electronic conduction mechanism through grain boundaries in heteroepitaxial gallium nitride layers was explained by applying the model, which included three effects: thermionic emission over potential barrier, thermionic field emission through potential barrier and thermionic field emission through scattering barrier. Space charge potential barriers height at the grain boundary layer was estimated to be 80 meV from the measurement of the temperature dependence of layer resistivity. Influence of the deep traps location in the different regions of active layers of the MSM detector on the device performance was evaluated by 2D numerical simulation.