Hydrogen assisted growth of high quality epitaxial graphene on the C-face of 4H-SiC

TL;DR

This paper presents a hydrogen-assisted method for growing high-quality epitaxial graphene on the C-face of 4H-SiC, which enhances domain size and surface quality compared to traditional techniques.

Contribution

The study introduces a novel hydrogen-assisted growth process that improves graphene quality and domain size on SiC substrates, revealing hydrogen's role as a carbon etchant and growth modulator.

Findings

Increased domain size of graphene with hydrogen assistance

Reduced thickness variation and defect formation

Enhanced surface morphology and multilayer suppression

Abstract

We demonstrate hydrogen assisted growth of high quality epitaxial graphene on the C-face of 4H-SiC. Compared with the conventional thermal decomposition technique, the size of the growth domain by this method is substantially increased and the thickness variation is reduced. Based on the morphology of epitaxial graphene, the role of hydrogen is revealed. It is found that hydrogen acts as a carbon etchant. It suppresses the defect formation and nucleation of graphene. It also improves the kinetics of carbon atoms via hydrocarbon species. These effects lead to increase of the domain size and the structure quality. The consequent capping effect results in smooth surface morphology and suppression of multilayer growth. Our method provides a viable route to fine tune the growth kinetics of epitaxial graphene on SiC.