Structural characterisation of diamondlike carbon films using Raman Spectroscopy

Raman Spectroscopy was employed for characterising the structure of diamondlike carbon films deposited using ion beam assisted deposition and ion beam sputtering, using various ion beam sources at low temperature. Films gown in a hydrogen-free ambient give a typical Raman pattern with a broad peak centred around the 1580cm(-1) band (G line), accompanied by a secondary peak centred at 600cm(-1) band, confirming an amorphous diamond-like carbon structure. Films deposited in a hydrocarbon ambient and using a nitrogen ion beam source tend to give an extra shoulder centred at 1400cm(-1) band, indicating the incorporation of hydrogen or nitrogen. However, with an excessive hydrogen content, degeneration of the Raman profile occurs, resulting in an almost linear spectrum. Based on deconvolution of the spectra, implications of the G line shift associated with structural variation of the films am discussed.