Fabrication of graphene nanoribbon by local anodic oxidation lithography using atomic force microscope

TL;DR

This paper demonstrates that local anodic oxidation lithography using an atomic force microscope can effectively fabricate graphene nanostructures, revealing layer-dependent oxidation and quantum Hall effects in the resulting devices.

Contribution

It introduces a novel application of LAO lithography for precise graphene nanodevice fabrication, including nanoribbons with controlled dimensions.

Findings

Oxidized area width depends on graphene layer number

Single-layer graphene device shows half-integer quantum Hall effect

Graphene nanoribbon exhibits conductance suppression indicating an energy gap

Abstract

We conducted local anodic oxidation (LAO) lithography in single-layer, bilayer, and multilayer graphene using tapping-mode atomic force microscope. The width of insulating oxidized area depends systematically on the number of graphene layers. An 800-nm-wide bar-shaped device fabricated in single-layer graphene exhibits the half-integer quantum Hall effect. We also fabricated a 55-nm-wide graphene nanoribbon (GNR). The conductance of the GNR at the charge neutrality point was suppressed at low temperature, which suggests the opening of an energy gap due to lateral confinement of charge carriers. These results show that LAO lithography is an effective technique for the fabrication of graphene nanodevices.