Effect of AlGaN Barrier Thickness on the Cut Off Frequency of AlGaN/GaN High Electron Mobility Transistors

An analytical- numerical model for the drain source and gate source currents of AlGaN/GaN based HEMTs has been developed that is capable to predict accurately the effects of AlGaN barrier thickness on the cut off frequency in different gate source and drain source biases. 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. In addition current in the barrier of AlGaN, traps density in AlGaN are also take in to account. The calculated model results are in very good agreement with existing experimental data for HEMTs device.