Decoupling graphene from SiC(0001) via oxidation

Abstract

When epitaxial graphene layers are formed on SiC(0001), the first carbon layer (known as the ``buffer layer''), while relatively easy to synthesize, does not have the desirable electrical properties of graphene. The conductivity is poor due to a disruption of the graphene $\ensuremath{\pi}$ bands by covalent bonding to the SiC substrate. Here we show that it is possible to restore the graphene $\ensuremath{\pi}$ bands by inserting a thin oxide layer between the buffer layer and SiC substrate using a low temperature, complementary metal-oxide semiconductor-compatible process that does not damage the graphene layer.