Surface structure of 3C-SiC(111) fabricated by C₆₀ precursor: A scanning tunneling microscopy and high-resolution electron energy loss spectroscopy study

The surface composition and structure of the 3C-SiC(111) surface prepared by thermal reaction of C₆₀ molecules with the Si(111) substrate are investigated with scanning tunneling microscopy and high-resolution electron energy loss spectroscopy. Three distinct surface reconstructions are observed by STM on the SiC(111) surfaces as the reaction temperature varied from 800 to 1200°C. The (2×2) and (2×3) reconstructions observed under low reaction temperature (<900 °C) are considered to be a C cluster-covered surface. The (3×3) structure yielded at the elevated temperature (1100 °C) is believed to be the Si-terminated 3C-SiC(111) surface. A transient (4×3) structure shows up at around 1000 °C during the annealing processing. The surface composition and reconstruction are further confirmed through the optical Fuchs-Kliewer surface phonon measured in situ by high-resolution energy loss spectroscopy. The diffusivity of Si atoms through SiC film at various temperatures is suggested as the main reason for the formation of different surface reconstructions.