NUMERICAL-ANALYSIS OF NONEQUILIBRIUM ELECTRON-TRANSPORT IN ALGAAS/INGAAS/GAAS PSEUDOMORPHIC MODFETS

Nonequilibrium electron transport in the InGaAs pseudomorphic MODFET’s has been analyzed with the moment equations approach. In our model, the momentum and energy balance equations for the two-dimensional electrons in the InGaAs channel are solved with relaxation times generated from a Monte Carlo simulation. The two-dimensional electron wave functions and the quantized states energies in the InGaAs quantum well are calculated exactly from the Schrödinger equation along the direction perpendicular to the quantum well. Also included is a two-dimensional Poisson equation solver. In the calculation, all of the equations are solved iteratively until a self-consistent solution is achieved. The simulation result for a realistic device structure with a 0.5-µm recessed gate shows a significant overshoot velocity of 4.5 × 107 cm/s at a drain bias of 1.0 V. Electron temperature reaches a peak value of around 2500 K under the gate. In energy transport, the diffusive component of the energy flux is found to be dominant in the high-field region. © 1990 IEEE