Surface structure of 3C-SiC(111) grown on Si(111) surface by C-60 precursor

The surface structure of cubic 3C-SiC(111) films prepared by thermal reaction of a Si(111) substrate with C-60 molecules has been studied by combined in situ measurements of scanning tunneling microscopy and high resolution electron energy loss spectroscopy (HREELS-STM). The (2Xn) surface reconstructions such as (2X2), (2X3) were observed under low reaction temperatures (<900 degrees C), and the Si-terminated SiC(111)-(3X3) was obtained by annealing the sample at higher temperatures (similar to 1100 degrees C). Optical surface phonon energies of 113+/-2 meV for SiC prepared at low temperatures and 116+/-2 meV for the films with (3X3) surface reconstruction were measured. The diffusivity of Si atoms from the substrate through the SiC film at various temperatures is suggested as the reason for the formation of different surface reconstructions of the SiC. (C) 1996 American Institute of Physics.