Competitive Growth and Etching of Epitaxial Graphene

Abstract

In this paper, we studied the competition of growth and etching during graphene epitaxial growth in the remote plasma enhanced chemical vapor deposition (r-PECVD) system. Epitaxial growth of graphene on HOPG substrates with a simultaneous etching process was systematically explored at various temperatures. It was found that etching of graphene by hydrogen radicals generated in the r-PECVD system was a critical factor during graphene’s growth for controlling the nucleation densities, lateral growth rates, and layer thickness. At temperatures lower than 490 °C, the etching effect is dominant, and there is no graphene nucleation. And at temperatures higher than 490 °C, the etching effect decreases gradually with rising temperature and the growth effect stands out. The optimized epitaxial growth was at 520 °C, and at that temperature a monolayer graphene single crystal was achieved with near perfect lattice structure on HOPG substrates.