Formation of a nitride interface in epitaxial graphene on SiC (0001)

We report on a nitride interface structure formed between epitaxial graphene and SiC (0001). The nitride interface can be obtained by the pretreatment of SiC in an Ar/N-2 atmosphere at 1600 degrees C, followed by graphene growth in Ar at 1700 degrees C. Our detailed high-resolution transmission electron microscopy revealed a nitride atomic layer between the 0th carbon layer and the SiC substrate. Due to the nitride interface, the interface carrier scattering was reduced, which resulted in an improvement of the room temperature mobility of graphene, indicating that this is another technique to modify the electronic properties of graphene.