Formation of Si-terminated SiC films on annealing C60 on a Si(001)-2 x 1 surface

Using synchrotron-radiation photoemission and low-energy electron diffraction (LEED), we studied the formation of SiC on annealing an atomically clean Si(001)-2 x 1 surface subsequently covered with a half monolayer of C60 molecules. The C 1s and Si 2p core-level spectra show that all C60 molecules are completely decomposed on annealing at 800 deg. C, and the liberated carbon atoms diffuse into the substrate to form a Si-terminated SiC film. An energy difference 0.5 eV between the surface and bulk components of the Si 2p cores indicates that the terminated silicon atoms on the SiC film have formed symmetric dimers. The SiC phase coexists with the uncovered silicon surface and occupies about 30% of the surface. The LEED pattern shows the surface to be a 2 x 1 reconstruction