Electrical properties of epitaxial graphene/n-SiC Schottky barrier diodes measured by conductive nanoprobe

Abstract The electrical characteristics of an epitaxial graphene/n-SiC Schottky diode were evaluated with scanning probe microscopy using a conductive nanoprobe as the metal electrode. Graphene nano-islands fabricated by the growth condition control technique effectively prevented reverse-leakage current. The ideality factor of the graphene nano-island/SiC junction was almost 1 for all the measured diodes. The estimated Schottky barrier height was 0.218 eV. The reverse-leakage current was proportional to the island size. In contrast, the forward current was not dependent on the island size. These results suggest that the nanoprobe acts as a metal electrode in the forward-biased condition, and the graphene nano-island acts as a conductive electrode in the reverse-biased condition. The intrinsic characteristics of nanoprobe/graphene nano-island/n-SiC junctions were revealed.