Evaluation of electron pressure effect in low-field drain region of submicron GaAs MESFET using ensemble Monte Carlo simulation

The ensemble Monte Carlo simulation is carried out to study effects of the electron pressure term on the mean electron velocity in the GaAs MESFET with a gate length of 0.2 μm. The four components of the mean electron velocity are separately evaluated on the main channel. It is found that the electron pressure component is comparable to the drift one or exceeds it in the low-field drain region. Including the electron pressure component into the drift one produces a large deviation from the Einstein relation and a too large effective mobility of 15000-30000 cm²/Vsec. So it is concluded that any device model for the submicron GaAs MESFET should not be based on a drift-diffusion model, but on a model explicitly including the electron pressure term