SURFACE-STRUCTURE OF 3C-SIC(111) FABRICATED BY C-60 PRECURSOR - A SCANNING-TUNNELING-MICROSCOPY AND HIGH-RESOLUTION ELECTRON-ENERGY-LOSS SPECTROSCOPY STUDY

The surface composition and structure of the 3C-SiC(111) surface prepa red by thermal reaction of C-60, molecules with the Si(111) substrate are investigated with scanning tunneling microscopy and high-resolutio n electron energy loss spectroscopy. Three distinct surface reconstruc tions are observed by STM on the SiC(111) surfaces as the reaction tem perature varied from 800 to 1200 degrees C, The (2x2) and (2x3) recons tructions observed under low reaction temperature (<900 degrees C) are considered to be a C cluster-covered surface, The (3x3) structure yie lded at the elevated temperature (1100 degrees C) is believed to be th e Si-terminated 3C-SiC(111) surface. A transient (4x3) structure shows up at around 1000 degrees C during the annealing processing. The surf ace composition and reconstruction are further confirmed through the o ptical Fuchs-Kliewer surface phonon measured bl situ by high-resolutio n energy loss spectroscopy. The diffusivity of Si atoms through SiC fi lm at various temperatures is suggested as the main reason for the for mation of different surface reconstructions. (C) 1996 American Vacuum Society.