Monolithically Patterned Wide-Narrow-Wide All-Graphene Devices

TL;DR

This paper theoretically demonstrates that monolithically patterned all-graphene GNRFETs offer improved electrostatics, reduced short-channel effects, and Ohmic contacts, leveraging atomistic simulations and quantum transport models.

Contribution

The study introduces a fully atomistic simulation of monolithic all-graphene GNRFETs, highlighting their performance benefits over traditional designs.

Findings

Enhanced electrostatic control in monolithic GNRFETs

Suppressed short-channel effects observed

Ohmic contacts at narrow-wide interfaces achieved

Abstract

We investigate theoretically the performance advantages of all-graphene nanoribbon field-effect transistors (GNRFETs) whose channel and source/drain (contact) regions are patterned monolithically from a two-dimensional single sheet of graphene. In our simulated devices, the source/drain and interconnect regions are composed of wide graphene nanoribbon (GNR) sections that are semimetallic, while the channel regions consist of narrow GNR sections that open semiconducting bandgaps. Our simulation employs a fully atomistic model of the device, contact and interfacial regions using tight-binding theory. The electronic structures are coupled with a self-consistent three-dimensional Poisson's equation to capture the nontrivial contact electrostatics, along with a quantum kinetic formulation of transport based on non-equilibrium Green's functions (NEGF). Although we only consider a specific device geometry, our results establish several general performance advantages of such monolithic devices (besides those related to fabrication and patterning), namely the improved electrostatics, suppressed short-channel effects, and Ohmic contacts at the narrow-to-wide interfaces.