Investigation of tetrahedral amorphous carbon films using X-ray photoelectron and Raman spectroscopy

Amorphous carbon containing very little hydrogen and having a highly tetrahedral structure has been prepared by the Filtered Cathodic Vacuum Arc (FCVA) technique under different deposition temperatures. Based on Raman measurement, it was found that the I_D/I_G intensity ratio, the G band peak position and the linewidth change with deposition temperature. From XPS measurement, it was demonstrated that four Gaussians components were required to have a good fit of the C 1s spectra of amorphous carbon film from which the relative concentration of sp³/sp² hybrids can be determined easily. These observations, together with the carbon network structure deduced from the Raman spectra, demonstrate that deposition temperature is an important factor in determining film properties such as sp³ content. Specifically, it was observed that the sp³ content derived from the Raman spectra parameter (I_D/I_G ratio) correlates well with that deduced from the XPS measurement data.