Realization of a High Mobility Dual-gated Graphene Field Effect Transistor with Al2O3 Dielectric

TL;DR

This paper reports the fabrication of dual-gated graphene FETs with high mobility using Al2O3 dielectric, demonstrating minimal impact on carrier mobility and proposing a device model for data fitting.

Contribution

It introduces a novel fabrication process for high-mobility dual-gated graphene FETs with Al2O3 dielectric and a model to interpret their electrical behavior.

Findings

Mobility over 8,000 cm2/Vs at room temperature

Al2O3 dielectric does not significantly degrade mobility

Device model successfully fits experimental data

Abstract

We fabricate and characterize dual-gated graphene field-effect transistors (FETs) using Al2O3 as top-gate dielectric. We use a thin Al film as a nucleation layer to enable the atomic layer deposition of Al2O3. Our devices show mobility values of over 8,000 cm2/Vs at room temperature, a finding which indicates that the top-gate stack does not significantly increase the carrier scattering, and consequently degrade the device characteristics. We propose a device model to fit the experimental data using a single mobility value.