Nanoscale Fabrication of Graphene by Hydrogen-Plasma Etching

TL;DR

This paper presents a method to fabricate graphene with atomically precise zigzag edges using hydrogen-plasma etching, preserving its structure and potentially improving nanoscale device performance.

Contribution

It introduces a novel hydrogen-plasma etching technique to produce graphene with aligned zigzag edges, maintaining its honeycomb structure at the nanoscale.

Findings

Graphene with zigzag edges successfully fabricated.

Atomic force microscopy and Raman spectroscopy confirm edge structure.

Hydrogen-radicals likely responsible for anisotropic etching.

Abstract

Graphene is attracting vast interest due to its superior electronic and mechanical properties. However, structure and electronic properties of its edge are often neglected, although they are important for nanoscale devices because the edge ratio becomes larger by decreasing the device size. In this study, we suggest a way to fabricate a graphene with atomically aligned zigzag edges by applying hydrogen-plasma etching (HPE) technique. By patterning a graphene prior to HPE, it is succeeded to shape a graphene in desired structure. Both atomic force microscopy and Raman spectroscopy confirm that the graphene shaped by this technique preserves its honeycomb structure even on the edge, which is aligned with zigzag structure. Although the mechanism of the anisotropic etching by hydrogen-plasma have not been clarified yet, the sample position dependence of the etching rate suggests that the hydrogen-radicals are responsible for the anisotropic etching.