FOURIER-TRANSFORM RAMAN-SPECTRA OF DIAMOND-LIKE CARBON-FILMS

Fourier transform (FT) Raman spectra (3500-50 cm-1) were recorded for hard diamond-like carbon (DLC) films deposited on silicon wafer substrates at various temperatures. The observed frequency of the graphitic optic zone center phonon (G) at 1595 cm-1 was found to remain constant with variations in the deposition temperature of the substrate, the excitation wavelength and the laser power. However, the disorder activated optical zone edge phonon (D), observed in the 1380-1250 cm-1 region, exhibits changes in the band maximum frequency with the above-mentioned variables. FT Raman spectroscopy, applied to these films, is shown to be a useful probe for the identification of various different types of diamond-like structures which are present.