SiC formation on Si(100) via C60 precursors

The interaction between C-60 molecules and the Si(100) surface and the preparation of silicon-carbide thin films by thermal reaction of C-60 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 C-60 coverage on the SiC formation will be discussed. It is found that the C-60 molecules bond covalently with silicon, and the number of bonds increase upon increasing the annealing temperature. Annealing at T greater than or equal to 830 degrees C entails the formation of stoichiometric silicon carbide clusters that coalesce to form a continuous SiC layer when the C-60 coverage is greater than one monolayer. Deep pits acting as silicon diffusion channels are present with dimensions that increase with the amounts of C-60. The interaction of C-60 With the SiC surface was also investigated. It is found that a similar covalent interaction is present in the two systems C-60/Si and C-60/SiC. (C) 2000 Elsevier Science B.V. All rights reserved.