Ensemble Monte Carlo simulation of a 0.35- mu m pseudomorphic HEMT

Theoretical analysis and precise comparison to experiment of the performance of a 0.35- mu m pseudomorphic Al/sub 0.15/Ga/sub 0.85/As/In/sub 0.15/Ga/sub 0.85/As high-electron-mobility transistor (HEMT) are presented. The calculations are made using an ensemble Monte Carlo simulation with the unique inclusion of real space transfer as well as the full details of the two-dimensional electron gas, velocity overshoot, and ballistic transport, and the effects of the two-dimensional electric field profile. The calculated current-voltage characteristic is compared to recent experimental measurements showing excellent agreement to within approximately 10% over a full range of gate and drain biases. It is found that near the source, the two-dimensional system dominates the transport physics, while near the pinch-off point, the effects of real space transfer become apparent. It is further determined that the high-speed performance of the pseudomorphic HEMT stems predominantly from the high electron confinement within the two-dimensional system, and the high electron mobility and confinement within the gamma valley in the bulk InGaAs.<
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