Optimization of graphene dry etching conditions via combined microscopic and spectroscopic analysis

TL;DR

This paper combines microscopic and spectroscopic techniques, including AFM, to optimize graphene dry etching conditions, ensuring complete removal of residues that could affect device performance.

Contribution

It introduces the use of AFM alongside optical methods to precisely determine optimal dry etching parameters for graphene.

Findings

AFM reveals residual graphene after optical methods indicate complete etching

Optimal etching conditions eliminate residues that could impair device quality

Combined analysis improves accuracy of graphene etching process

Abstract

Single-layer graphene structures and devices are commonly defined using reactive ion etching and plasma etching with O2 or Ar as the gaseous etchants. Although optical microscopy and Raman spectroscopy are widely used to determine the appropriate duration of dry etching, additional characterization with atomic force microscopy (AFM) reveals that residual graphene and/or etching byproducts persist beyond the point where the aforementioned methods suggest complete graphene etching. Recognizing that incomplete etching may have deleterious effects on devices and/or downstream processing, AFM characterization is used here to determine optimal etching conditions that eliminate graphene dry etching residues.