Comeback of epitaxial graphene for electronics: large-area growth of bilayer-free graphene on SiC

TL;DR

This paper introduces a novel polymer-assisted sublimation growth method for epitaxial graphene on SiC, achieving large-area, defect-free monolayer graphene with high electronic quality suitable for commercial applications.

Contribution

The study presents a new fabrication technique that produces large-area, bilayer-free graphene with high reproducibility, overcoming previous limitations in wafer-scale epitaxial graphene growth.

Findings

Achieved ultra-smooth, defect-free monolayer graphene on SiC

Demonstrated high electron mobilities and quantum resistance precision

Established polymer-assisted sublimation as a promising commercial method

Abstract

We present a new fabrication method for epitaxial graphene on SiC which enables the growth of ultra-smooth defect- and bilayer-free graphene sheets with an unprecedented reproducibility, a necessary prerequisite for wafer-scale fabrication of high quality graphene-based electronic devices. The inherent but unfavorable formation of high SiC surface terrace steps during high temperature sublimation growth is suppressed by rapid formation of the graphene buffer layer which stabilizes the SiC surface. The enhanced nucleation is enforced by decomposition of polymer adsorbates which act as a carbon source. With most of the steps well below 0.75 nm pure monolayer graphene without bilayer inclusions is formed with lateral dimensions only limited by the size of the substrate. This makes the polymer assisted sublimation growth technique the most promising method for commercial wafer scale epitaxial graphene fabrication. The extraordinary electronic quality is evidenced by quantum resistance metrology at 4.2 K with until now unreached precision and high electron mobilities on mm scale devices.