Physics-based modeling of submicron GaN permeable base transistors

We present the first physics-based nonstationary modeling of a submicron GaN permeable base transistor. Three different transport models are compared: drift-diffusion, energy balance, and ensemble Monte Carlo. Transport parameters and relaxation times used by the carrier transport equations are consistently derived from particle simulation. The current-voltage (I-V) characteristics predicted with the energy balance model are in good agreement with those obtained from direct Monte Carlo device simulation. On the other hand, the drift-diffusion approach appears to be inadequate for the device under study, even if improved high-field mobility models are adopted.