Low-temperature formation of epitaxial graphene on 6H-SiC induced by electron beam irradiation

It is observed that epitaxialgraphene forms on the surface of a 6H-SiC substrate by irradiatingelectron beam directly on the sample surface in high vacuum at relatively low temperature (???670 ??C). The symmetric shape and full width at half maximum of 2D peak in the Raman spectra indicate that the formed epitaxialgraphene is turbostratic. The gradual change of the Raman spectra with electron beamirradiation time increasing suggests that randomly distributed small grains of epitaxialgraphene form first and grow laterally to cover the entire irradiated area. The sheet resistance of epitaxialgraphene film is measured to be ???6.7 k??/sq