Bonding Structure of CN_x Films Synthesized by Implanting Nitrogen into Diamond Films

CN x films were synthesized by implanting nitrogen ions (with the energy of 10 keV and 60 keV , respectively) into diamond films. The bonding structures of the implanted films and diamond films were investigated by using both Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). For the diamond film implanted by 10 keV nitrogen ions, its Raman spectrum exhibits a stronger diamond peak at 1 332 cm -1 and a weak graphitic peak (G band) at 1 550 cm -1 , while the N 1s XPS data show two main peaks at ~398 5 eV and ~400 0 eV, respectively. As for the diamond film implanted by 60 keV nitrogen ions, the dominant peak in N 1s XPS spectrum appears at ~400 0 eV . Correspondingly, the graphitic peak in the Raman spectrum becomes pronounced. On the basis of the comparison with the Raman spectra, the assignments of N 1s binding states, based on XPS, in the implanted films are as follows: the peak at ~400 0 eV is attributed to C—N sp 2 bonding, whereas the peak at ~398 5 eV is ascribed to C—N sp 3 bonding.