A DIRECT APPROACH TO SOLVING THE DRIFT-DIFFUSION MODEL-EQUATIONS FOR USE IN CERTAIN MOSFET DEVICES

The behavior of metal oxide semiconductor field effect transistors (MO SFETs) has frequently been modeled using the drift-diffusion partial d ifferential equations. In this paper, we show how extensions of previo usly studied techniques may be applied to these equations to obtain bo th current-voltage relationships and pointwise variation of the potent ial functions arising in a number of practical cases. While our method makes use of perturbation theory, we are able to avoid the complicate d asymptotic matching methods that have been widely adopted by a numbe r of authors for studying such MOSFETs. Our numerical approach can tre at the important practical case of variable doping and gives rise to a ccurate, and numerically stable, solutions of the model equations.