SiC formation by C60 molecules as a precursor:: A synchrotron-radiation photoemission study of the carbonization process

Formation of SiC upon annealing an atomically clean Si(001)-2 X I surface covered with half a monolayer of C-60 molecules has been investigated by a synchrotron-radiation photoemission. C-60 molecules are chemisorbed at room temperature on the silicon Surface via Si-C-60 hybridization to form covalent bonds. During annealing of the film at 700 degrees C, Si atoms in the first layer below the Surface move upward to bond With C-60 molecules, enhancing the formation Of SixC60 and resulting in weakened C-C bonds within C-60 molecules. Upon further annealing to 750 degrees C, most C-60 molecules decompose and formation of the SiC film begins. Total decomposition Of C-60 molecules occurs at 800 degrees C, and only a SiC film is then found. (c) 2006 American Vacuum Society.