Structural characterization of nitrogen doped diamond-like carbon films deposited by arc ion plating

Nitrogen doped diamond-like carbon films were deposited on Si (1 0 0) substrates by arc ion plating (AIP) technique under different N-2 volume percentage in the gas mixture of Ar and N-2. The deposited films were characterized by Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Raman spectra indicate that the I-D/I-G ratio increases with increasing the N-2 volume percentage. XPS analysis shows a strong influence of the N-2 volume percentage on the N atom concentration and the chemical bonding states in the deposited films. Nitrogen content of the deposited films increased with the increasing of N-2 volume percentage. The maximum N concentration and N/C atomic ratio are up to 12.7 at.% and 0.162 at the 90 vol.% N-2, respectively. From decomposition of XPS C 1s peaks, it shows that the nitrogen doped diamond-like carbon films consist of amorphous carbon-carbon bonding ((SPC)-C-2-C and sp(3)C-C), N atoms bonded to sp(3)-hybridized C atoms (sp(3)C-N) and N atoms bonded to sp(2)-hybridized C atoms (sp(2)C-N). The total content of sp(3) bonding decreases with increasing N-2 volume percentage. XPS N Is spectra show that there exist the N-sp(2)C and N-sp(3)C bonding in the deposited nitrogen doped diamond-like carbon films. As the N-2 volume percentage increases, the N-sP(3)C bonding content increases, but the N-(SPC)-C-2 bonding content decreases. (C) 2004 Elsevier B.V. All rights reserved.