TCAD based modeling and simulation of Graphene Nanostructured FET (GFET) for High Frequency Performance

Abstract

 In this paper, the modeling of a Graphene based Field Effect Transistor(GFET) is presented. The modeling is done using the SILVACO TCAD tools. The structure is developed in ATLAS virtual framework and the model is used to investigate the performance of graphene based FET. First we deposit 5nm thick polysilycon film instead of graphene film to generate the device structure. Graphene is modeled as a semiconductor, a carrier mobility of 10,000 cm2/V-s and used as the channel material. The characteristics curves: output characteristic and transfer curve are plotted using TONYPLOT. Pristine graphene has no band gap. So it is considered as semi-metal or zero bandgapsemiconductor. Due to the lack of bandgap, ION/IOFF is relatively low compared to the Silicon based transistor, so for digital logic circuits, GFET still lags behind comparing to Si transistors. It is more suitable for RF application with its very high mobility. Therefore, in this paper, the parameters which are considered to the FOMs of RF transistors i.e. maximum cut off frequency (fT) and the maximum frequencies of oscillations (fmax) are extracted.