2-D modeling of potential distribution and threshold voltage of short channel fully depleted dual material gate SOI MESFET

A two-dimensional analytical model for the potential distribution along the bottom channel of the fully depleted region of dual material gate (DMG) SOI MESFET is presented. The potential distribution is modeled by solving the Poisson equation with proper boundary conditions. The model for the potential distribution is extended to derive an analytical expression for the threshold voltage. The accuracy of the model is verified by comparing the analytical results with the results of GENESISe device simulator for different device parameters. The comparison demonstrates an excellent agreement between the analytical and simulation results. The results reveal that the DMG structure introduces a step function in the bottom potential profile in the depleted region. This function reduces the drain induced barrier lowering (DIBL) effect when compared to the conventional single metal gate (SMG) structure. Finally, the effects of different DMG structure parameters on the amount of DIBL reduction are also investigated.