Transmission Electron Microscopy and Raman-Scattering Spectroscopy Observation on the Interface Structure of Graphene Formed on Si Substrates with Various Orientations

Graphene can be grown on three major low-index substrates of Si(111), (110), and (001) by forming a 3C-SiC thin film and by subliming Si atoms from the top few layers of the SiC film. We have investigated the structure of graphene/3C-SiC interface by cross-sectional transmission electron microscopy (XTEM) and Raman-scattering spectroscopy. While the interface layer quite similar to that on the graphene/6H-SiC(0001) face is found to exist on the 3C-SiC(111)/Si(111) substrate, no such interface structure exists on the (110)- and (001)-oriented faces.