Low-Energy-Electron-Diffraction and X-ray-Phototelectron-Spectroscopy Studies of Graphitization of 3C-SiC(111) Thin Film on Si(111) Substrate

Epitaxial graphene can be formed on silicon substrates by annealing a 3C-SiC film formed on a silicon substrate in ultrahigh vacuum (G/3C-SiC/Si). In this work, we explore the graphitization process on the 3C-SiC(111)/Si(111) surface by using low-energy electron diffraction and X-ray photoelectron spectroscopy (XPS) and compare them with that on 6H-SiC(0001). Upon annealing at $T\geq 1150$ °C, the 3C-SiC(111)/Si(111) surface follows the sequence of ($\sqrt{3}{\times}\sqrt{3}$)R30°, ($6\sqrt{3}{\times}6\sqrt{3}$)R30°, and $(1{\times}1)_{\text{graphene}}$ in the surface structures. The C 1s core level according to XPS indicates that a buffer layer , identical with that in G/6H-SiC(0001), exists at the G/3C-SiC(111) buffer. These observations strongly suggest that graphitization on the surface of the 3C-SiC(111) face proceeds in a similar manner to that on the Si-terminated hexagonal bulk SiC crystals.