An improved model to assess temperature-dependent DC characteristics of submicron GaN HEMTs

A modified analytical model for the current-voltage (I-V) characteristics of AlGaN/GaN high-electron-mobility transistors (HEMTs) is presented, considering the temperature-dependent: (a) Schottky barrier height, (b) energy bandgap discontinuity, (c) carrier mobility, and (d) saturation velocity. It is demonstrated that the Schottky barrier height and energy bandgap discontinuity decrease with increase of the temperature. The effective mobility of the two-dimensional electron gas (2-DEG) also decreases with increasing temperature, causing a reduction in the output current of the device. The model was tested over a wide range of temperatures (300-500 K) and bias, and it was observed that the developed model can successfully predict the I-V characteristic of the device with reasonable accuracy, especially at high temperatures (similar to 500 K). It is shown that the developed model offers, on average, a 39% improvement for the temperature variation, from 300-500 K, relative to the best model reported in literature.