FILM GROWTH AND SURFACE-REACTIONS OF C-60 ON SI(100)H(2X1)

High-resolution electron-energy-loss spectroscopy (HREELS) has been us ed to characterize C-60 films up to 4 monolayers thick grown at room t emperature on hydrogen-terminated Si(100). Our results show that compa red with C-60 films on clean Si(100) surfaces a considerably higher de gree of order in the as-deposited films is achieved. At low coverages the observed C-60 vibrational modes and the Si-H vibrations of the sub strate are essentially unshifted, indicating a van der Waals-type inte raction between C-60 and Si(100)H(2x1). After annealing at 450 K the f ilm order is substantially increased. Annealing at 600 K results in de sorption of the C-60 multilayers and a hydrogen-transfer reaction from the surface to the adsorbed monolayer molecules. When annealing the s ample at 800 K, the remaining surface terminating hydrogen desorbs and evidence for a change in the C-60 bonding configuration is found. Fin ally, flashing the sample at 1300 K leads to the formation of silicon carbide.