A valence-band and core-level photoemission study of a-SixC1-x thin films grown by low-temperature low-pressure chemical vapour deposition

Amorphous SixC1-x thin films have been grown by low-pressure chemical vapour deposition at 800 K from Si2H6 and C2H2 in the x concentration range 0.5 <= x < 0.7. Measurements of the valence-band and core-level photoemission spectra using X-ray photoemission spectroscopy and synchrotron radiation have shown a clear change in the electronic structure for 0.55 < x < 0.60, where the films appear to lose their predominant SiC character and acquire an increasing Si-like signature in the spectra. X-ray diffraction data on polycrystalline SixC1-x films obtained by excimer laser annealing during growth have shown the formation of a dominant 3C-SiC phase up to x=0.6, while for higher x the growth of a poly-Si phase has been observed.