Theoretical analysis of an Al0.15Ga0.85As/In 0.15Ga0.85As pseudomorphic HEMT using an ensemble Monte Carlo simulation

The calculations presented include the full details of the two-dimensional electron gas, nonstationary transport effects, real-space transfer, and the effects of the two-dimensional electric field profile. As a test of the accuracy with which the calculations successfully model a real device, the calculated current-voltage characteristic is compared to the experimentally measured data for a comparable device. Excellent agreement is obtained between the theory and experiment. The effect of velocity overshoot and real-space transfer on the device performance is investigated as a function of gate and drain bias. It is found that at under certain gate-bias conditions, real-space transfer into both the AlGaAs and GaAs layers occurs, leading to an enhanced substrate leakage current as well as lowered overall speed of performance