SiC formation on Si(100) via C60 precursors

The interaction between C₆₀ molecules and the Si(100) surface and the preparation of silicon-carbide thin films by thermal reaction of C₆₀ molecules with the Si(100) surface have been investigated using X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, reflection high-energy electron diffraction and atomic force microscopy measurements. The effects of annealing temperature and C₆₀ coverage on the SiC formation will be discussed. It is found that the C₆₀ molecules bond covalently with silicon, and the number of bonds increase upon increasing the annealing temperature. Annealing at T≥830°C entails the formation of stoichiometric silicon carbide clusters that coalesce to form a continuous SiC layer when the C₆₀ coverage is greater than one monolayer. Deep pits acting as silicon diffusion channels are present with dimensions that increase with the amounts of C₆₀.

The interaction of C₆₀ with the SiC surface was also investigated. It is found that a similar covalent interaction is present in the two systems C₆₀/Si and C₆₀/SiC.