Reversible graphitization of SiC: A route towards high-quality graphene on a minimally step bunched substrate

Abstract

We show that the thermal decomposition of SiC (0001) surface is reversible, if carried out in near-equilibrium conditions, with an external Si atomic beam applied to the substrate. Taking advantage of this observation we design a novel process, allowing for the growth of uniform, few-layers, ABC-stacked graphene. This process is composed of two phases; the first is a graphene film growth and the second is its reduction to the desired thickness. We find that, when using this scheme instead of the conventional ones the heavy step bunching on the substrate is avoided, and the step heights remain below 2.75 nm.Since the step bunching is one of the most important factors prohibiting the use of epitaxial graphene on SiC in certain application areas, such as analog electronics or sensing, our method has the potential to be applied in future wafer-scale graphene technologies and processes. Moreover, the results obtained in this work exemplify general near-equilibrium phenomena and therefore they may be also relevant for growth methods of other 2D materials.