Influence of deposition pressure on the composition and structure of carbon nitride films deposited by direct current plasma assisted pulsed laser ablation

Carbon nitride films were deposited by pulsed laser ablation of graphite ta rget under nitrogen atmosphere at room temperature. A direct current discha rge apparatus was used to supply active nitrogen species during the deposit ion of carbon nitride films. FTIR and X-ray photoelectron spectroscopy (XPS ) were used to characterize the composition and bonding structure of the de posited films. The influence of deposition pressure in the range 1-20 Pa on the composition and bonding structure of carbon nitride films was studied. The composition and structure are strongly depended on the deposition pres sure. The NIC ratio in the deposited films increases linearly with increasi ng deposition pressure to 10 Pa, further increase of the deposition pressur e results in the slight increase of N/C ratio. FTIR spectra indicate the ex istence of C-N, C=N and C equivalent toN bonds in the deposited films. Incr easing deposition pressure results in the increase of C=C. C=N and C equiva lent toN bonds fraction and decrease of the C-N bonds fraction in the depos ited films. XPS results are consistent with FTIR results. which indicate th at increasing deposition pressure leads to the increase in the fraction of N atoms bonded to sp(2) C atoms and the fraction of sp(2) C atoms bonded to N atoms, and the decrease in the fraction of N atoms bonded to sp(3) C ato ms and the fraction of sp(3) C atoms bonded to N atoms. (C) 2001 Elsevier S cience B.V. All rights reserved.