Monte Carlo analysis of hot electron injection in the passivation layer of GaN HEMTs

We investigate the injection of hot electrons in the passivation layer above the drift region of GaN HEMTs by means of Monte-Carlo transport simulations. We find that the lateral component of the electric field in the AlGaN layer delivers a non-negligible kinetic energy to the electrons, thus enhancing injection in the passivation at the top, an effect that is not captured by the standard hot-carrier injection models developed for Si devices that requires the development of ad-hoc hot-carrier injection models for GaN devices. The implications of our calculations for the understanding of reliability and dynamic-Ron are also briefly discussed.