A small-signal GFET equivalent circuit considering an explicit contribution of contact resistances

Abstract

A small-signal equivalent circuit for graphene field-effect transistors is proposed considering the explicit contribution of effects at the metal-graphene interfaces by means of contact resistances. A methodology to separate the contact resistances from extrinsic parameters, obtained by a de-embedding process, and intrinsic parameters of the circuit is considered. The experimental highfrequency performance of two different GFET technologies is properly described by the proposed small-signal circuit. The correct detachment of contact resistances from the internal transistor enables to study their impact on the intrinsic cutoff frequency of the devices under study.