Numerical performance evaluation of AlGaN/GaN high electron mobility transistors including gate length effects

A numerical model is developed to predict the transport properties and small signal parameters of AlGaN/GaN high electron mobility transistors with different gate length. Salient features of the model are incorporated of fully and partially occupied sub-bands in the interface quantum well, combined with a self-consistent solution of the Schrödinger and Poisson equations and including the polarization effects. In addition, self-heating and the temperature effects, voltage drops in the ungated regions of the device, buffer-trapping (deep donor, deep acceptor and shallow donor) effects and spacer layer thickness effects 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.