EUV induced defects on few-layer graphene

TL;DR

This study demonstrates that EUV radiation induces defects in few-layer graphene, with increased defect density in hydrogen environments, primarily due to oxidation despite reducing conditions, as shown by Raman and XPS analyses.

Contribution

It provides new insights into defect formation mechanisms in graphene under EUV exposure, especially in hydrogen-rich environments, using combined Raman and XPS techniques.

Findings

EUV exposure increases defect density in graphene.

Hydrogen environment enhances EUV-induced defect formation.

Oxidation remains a primary defect source despite reducing conditions.

Abstract

We use Raman spectroscopy to show that exposing few-layer graphene to extreme ultraviolet (EUV, 13.5 nm) radiation, i.e. relatively low photon energy, results in an increasing density of defects. Furthermore, exposure to EUV radiation in a H2 background increases the graphene dosage sensitivity, due to reactions caused by the EUV induced hydrogen plasma. X-ray photoelectron spectroscopy (XPS) results show that the sp2 bonded carbon fraction decreases while the sp3 bonded carbon and oxide fraction increases with exposure dose. Our experimental results confirm that even in reducing environment oxidation is still one of the main source of inducing defects.