Large-Signal Model of Graphene Field-Effect Transistors—Part I: Compact Modeling of GFET Intrinsic Capacitances

Abstract

Abstract-We present a circuit-compatible compact model of the intrinsic capacitances of graphene field-effect transistors (GFETs). Together with a compact drain current model, a largesignal model of GFETs is developed combining both models as a tool for simulating the electrical behavior of graphene-based integrated circuits, dealing with the DC, transient behavior, and frequency response of the circuit. The drain current model is based in a drift-diffusion mechanism for the carrier transport coupled with an appropriate field-effect approach. The intrinsic capacitance model consists of a 16-capacitance matrix including self-capacitances and transcapacitances of a four-terminal GFET. To guarantee charge conservation, a Ward-Dutton linear charge partition scheme has been used. The large-signal model has been implemented in Verilog-A, being compatible with conventional circuit simulators and serving as a starting point toward the complete GFET device model that could incorporate additional non-idealities.

Large-signal model of 2DFETs: compact modeling of terminal charges and intrinsic capacitances

“…Due to charge conservation and considering a reference-independent model, only nine independent capacitances are needed to describe the 4T device. In addition, taking advantage of the relations between the top-and back-gate capacitances, 25 the computation of only four capacitances is enough; for instance, C gg , C gd , C dg , and C dd can be chosen as the independent set.…”

Sensitivity analysis of a Graphene Field-Effect Transistors by means of Design of Experiments

“…A design leading to performances insensitive to the tolerances affecting these parameters is desired. Different simulations have been performed with Cadence Virtuoso Spectre Circuit Simulator by using an equivalent electric model of the component (Fig.2), The model has been developed and validated with experimental data by some of the authors in previous studies [10,11]. For completeness and clarity reasons, the main features of this component are illustrated in the sequel.…”

Small-Signal Model for 2D-Material Based FETs Targeting Radio-Frequency Applications: The Importance of Considering Nonreciprocal Capacitances

“…In order to assess the new expressions (7) and (9) to estimate the RF FoMs, we have obtained the small-signal parameters of a prototype GFET described in Table I from the large-signal model presented in [17], [34]. The gate bias dependence of the transconductance and output conductance is depicted in Figs.…”

“…The small-signal elements are: gm transconductance, gds output conductance and Cgs, Cgd, Csd and Cdg intrinsic capacitances. The physical meaning of the elements is explained in[17] for a GFET. Rg is the gate resistance and Rd, Rs account for the contact and access resistances of the drain and source respectively.…”