Realization of a high mobility dual-gated graphene field-effect transistor with Al2O3 dielectric

Abstract

We fabricate and characterize dual-gated graphene field-effect transistors using ${\text{Al}}_2{\text{O}}_3$ as top-gate dielectric. We use a thin Al film as a nucleation layer to enable the atomic layer deposition of ${\text{Al}}_2{\text{O}}_3$ . Our devices show mobility values of over $8000{\text{cm}}^2/\text{V}\text{s}$ 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.