A quasi-two-dimensional charge transport model of AlGaN/GaN high electron mobility transistors (HEMTs)

A quasi-two-dimensional charge transport model of AlGaN/GaN high electron mobility transistor has been developed that is capable of accurately predicting the drain current as well as small-signal parameters such as drain conductance and device transconductance. This model built up with incorporation of fully and partially occupied sub-bands in the interface quantum well, combined with a numerically self-consistent solution of the Schrödinger and Poisson equations. In addition, nonlinear polarization effects, self-heating, voltage drops in the ungated regions of the device are also taken into account. Also, to develop the model, the accurate two-dimensional electron gas mobility and the electron drift velocity have been used. The calculated model results are in very good agreement with existing experimental data for AlmGa1−mN/GaN HEMT devices with Al mole fraction within the range from 0.15 to 0.50, especially in the linear regime of I-V curve.