The N1s XPS peak was deconvoluted into three peaks with binding energies BE = 398.3, 400.0 and 402.0 eV, which were assigned to sp3 C-N and sp2 C-N and N-N bondings, respectively. The peak position of C1s spectra as found by X-ray photoelectron spectroscopy (XPS) analysis shifted to higher binding energy with decreasing nitrogen ion energy. The nitrogen content in prepared films increased with decreasing the nitrogen ion energy, and showed a constant value of 30 at.% below 200 eV. The dependence of the stoichiometry and formed chemical bonds on the nitrogen ion energy was investigated. The transport ratio of carbon atoms to nitrogen ions at the substrate was 1.0. The energy of nitrogen ions was changed between eV. The ratio of carbon to nitrogen atoms with sp 3 bonds was found to be 1.43 in the films grown at nitrogen ion energies of 50 eV, which is close to that of C 3N 4 compound predicted as a superhard material.Ībstract = "Carbon nitride films were prepared by nitrogen ion assisted pulsed KrF excimer laser deposition of graphite onto Si(100) substrates. The nitrogen content with the sp 3 C-N bond type was estimated at 18.0 at.% by XPS.
The carbon content with the sp 3 C-N bond type was estimated at 12.6 at.% from electron energy loss spectroscopy (EELS) analysis. The ratio of sp 3 to sp 2 bonded nitrogen atoms increased with decreasing ion energy, and showed a maximum value in the energy interval between 50 and 75 eV. The N1s XPS peak was deconvoluted into three peaks with binding energies BE = 398.3, 400.0 and 402.0 eV, which were assigned to sp 3 C-N and sp 2 C-N and N-N bondings, respectively. Both results indicated that the graphitizing tendency could occur with the increase in nitrogen content in the films.Carbon nitride films were prepared by nitrogen ion assisted pulsed KrF excimer laser deposition of graphite onto Si(100) substrates. The Raman measurements demonstrated that the G peak position shifted towards higher frequency from 1,561 to 1,578 cm(-1) and the ratio of ID/IG also rose with the increase in nitrogen content.
It was shown that the tetrahedral hybridization component was still dominant even though the ratio of sp2/sp3 obtained from C(1s) spectra rose with the increase in nitrogen content. In order to discover clearly the changing regularities of the microstructure of the films, the XPS C(1s) spectra and Raman spectra were deconvoluted using a Gaussian-Lorentzian mixed lineshape. Additionally, the half width of C(1s) peak gradually was also broadened with increasing nitrogen content. The shift of C (1s) peak position could be ascribed to the chemical bonding between carbon and nitrogen atoms even though more three-fold coordinated sp2 configuration as in graphite was formed when the films were doped with more nitrogen atoms. The peak position of C (1s) core level moved towards higher binding energy with the increase in nitrogen content. It was shown that the nitrogen content in the films increased from 0.84 at% to 5.37 at% monotonously when the nitrogen flow rate was varied from 2 seem to 20 sccm. The configuration of ta-C : N films was investigated by means of X-ray photoelectron spectroscopy (XPS) and visible Raman spectroscopy. The nitrogen content in the films was controlled by changing the flow rate of nitrogen gas. Nitrogenated tetrahedral amorphous carbon (ta-C : N) films were prepared on the polished C-Si substrates by introducing highly pure nitrogen gas into the cathode region and the depositing chamber synchronously using filtered cathodic vacuum arc (FCVA) technology.