Modeling of Forward Gate Leakage Current in MOSHEMT Using Trap-Assisted Tunneling and Poole–Frenkel Emission

Abstract

Investigation of various forward gate leakage current mechanisms in an AlGaN/GaN metal–oxide–semiconductor high-electron-mobility transistor is done in this paper. During high temperature ( $T>388$ K), the trap-assisted tunneling (TAT) mechanism dominates the gate leakage current at low electric field for a range of gate biases from 0 to 0.2 V, whereas the Poole–Frenkel emission is the major component during medium and high electric field. During low temperature ( $T K), TAT alone is dominant and consistent throughout the whole range of electric field. A formulation of vertical electric field, across the oxide and barrier, is framed by incorporating oxide/barrier interface density of states. Then a physics-based compact analytical model for the TAT mechanism is developed and along with the existing PFE model, the forward gate leakage current is calculated. The results of the developed model in different regions of forward gate characteristics are in good agreement with the experimental results available in the literature.