Local anodic oxidation on hydrogen-intercalated graphene layers: oxide composition analysis and role of the silicon carbide substrate

TL;DR

This study explores nanoscale local anodic oxidation on hydrogen-intercalated graphene on silicon carbide, revealing how bias voltage influences oxidation regimes and graphene etching, with detailed compositional analysis of the oxide and substrate effects.

Contribution

It provides new insights into the oxidation mechanisms of graphene on SiC and demonstrates controlled etching and compositional analysis using advanced microscopy techniques.

Findings

Partial and total graphene etching achieved by bias tuning.

Oxide composition and substrate impact characterized.

Two oxidation regimes identified via micro-Raman spectroscopy.

Abstract

We investigate nanoscale local anodic oxidation (LAO) on hydrogen-intercalated graphene grown by controlled sublimation of silicon carbide (SiC). Scanning probe microscopy (SPM) was used as a lithographic and characterization tool in order to investigate the local properties of the nanofabricated structures. The anomalous thickness observed after the graphene oxidation process is linked to the impact of LAO on the substrate. Micro-Raman spectroscopy was employed to demonstrate the presence of two oxidation regimes depending on the applied bias. We show that partial and total etching of monolayer graphene can be achieved by tuning the bias voltage during LAO. Finally, a complete compositional characterization was achieved by scanning electron microscopy and energy dispersive spectroscopy (EDS).