AlGaN/GaN HEMT device structure optimization design

A novel Composite-Channel Al_xGa_1-xN/Al_yGa_1-yN/ GaN HEMT is designed and optimized. The influence of two-dimensional electron gas and electric field on device structure parameter is obtained from the self-consistent solution basing on theory of semiconductor energy band and quantum well. The influence of the layer structure of the device on its performance is obtained from simulation of TCAD software. Combining with results of theory analysis and simulation results, the optimization structure Al_0.31Ga_0.69N/-Al_0.04Ga_0.96N/GaN HEMT is proposed. The simulation results show that the device with gate length of 1 mum and gate width of 100 mum has the maximum transconductance of 300 mS/mm and the little fluctuation in the gate voltage from -2V to 1V that shows the excellent linearity of the device, the maximum current density of 1300 mA/mm, the cut-off frequency of 11.5 GHz and a maximum oscillation frequency of 32.5 GHz.