Two-dimensional analytical modelling of drain current collapse in AlGaN/GaN HEMTs using multi-phonon ionisation by an electric field

A two-dimensional analytical model involving a multi-phonon tunneling process at high static electric fields in AlGaN/GaN HEMTs to explain the drain current collapse has been attempted. This model successfully explains the sudden recovery of drain current at a particular drain voltage for different applied gate voltages due to an exponential increase in emission rate from surface donors. This phenomenon leads to a rapid collapse of the virtual gate formed from the gate edge towards the drain, eventually causing a full recovery of the drain current to an uncollapsed condition. This paper also includes the effect of an increase in channel temperature by self-heating due to applied gate and drain voltages.