High On/Off Ratio Graphene Nanoconstriction Field Effect Transistor

TL;DR

This paper introduces a novel method using feedback controlled electromigration to create sub-10 nm graphene nanoconstrictions, achieving record high on/off ratios in graphene FETs at room temperature.

Contribution

It presents a new fabrication technique enabling sub-10 nm graphene nanoconstrictions with high on/off ratios, surpassing previous limitations of nanolithography.

Findings

On/off ratios exceeding 1000 at room temperature for narrowest devices

First demonstration of large room temperature on/off ratios in patterned graphene FETs

Confinement-induced energy gap observed as device width decreases

Abstract

We report a method to pattern monolayer graphene nanoconstriction field effect transistors (NCFETs) with critical dimensions below 10 nm. NCFET fabrication is enabled by the use of feedback controlled electromigration (FCE) to form a constriction in a gold etch mask that is first patterned using conventional lithographic techniques. The use of FCE allows the etch mask to be patterned on size scales below the limit of conventional nanolithography. We observe the opening of a confinement-induced energy gap as the NCFET width is reduced, as evidenced by a sharp increase in the NCFET on/off ratio. The on/off ratios we obtain with this procedure can be larger than 1000 at room temperature for the narrowest devices; this is the first report of such large room temperature on/off ratios for patterned graphene FETs.