Interfacial properties of silicon nitride grown on epitaxial graphene on 6H-SiC substrate

Abstract

Si 3N 4 thin films were grown on epitaxial graphene layers on 6H-SiC (0001) substrate, and the related interfacial properties have been studied by using high-resolution transmission electron microscopy (TEM), X-ray photoemission spectroscopy (XPS), and first-principles calculations. It is found that Si 3N 4 forms uniform coverage on graphene/SiC. The interaction between graphene and Si 3N 4 is weak, and the measured barrier height between them is 2.7 ± 0.1 eV, which is high enough to minimize the tunneling carriers. The in situ thermal treatment shows that the Si 3N 4/graphene/6H-SiC heterojunctions are thermally stable up to 800 °C. These results suggest promising application of Si 3N 4 as a dielectric in graphene-based electronic devices. © 2012 American Chemical Society.