THE EFFECT OF USING DIFFERENT TRANSPORT MODELS IN COMPUTER-SIMULATIONS OF THE PERMEABLE-BASE TRANSISTOR

The PET is a short channel device and hot electron effects are expecte d to be important and the transport model used in the simulation is cr itical. The present work compares the effect of different transport mo dels on the operation of a submicron PET. The transport model used are the ordinary drift-diffusion model and the hydrodynamicc models as th ey are implemented in MEDICI Ver. 1.1. In submicron devices the transp ort parameters become both device and bias dependent. The transport pa rameters are directly related to the distribution function and should be extracted From the solution of Boltzmann's Transport Equation (BTE) . The most popular and effective way of solving the BTE is Monte Carlo simulation. In this work we have extracted transport parameters from Monte Carlo simulation using one dimensional boundary for particles an d a fixed electric field extracted from two-dimensional simulation in MEDICI. The Monte Carlo simulation, parameter extraction and MEDICI si mulation have been repeated until the change in electric field between iterations could be neglected. Both I-V and f(T) results have been an alysed. It is clear that the hydrodynamic model gives higher current l evels and higher f(T) than the drift-diffusion model.