Co-implantation of carbon and nitrogen into silicon dioxide for synthesis of carbon nitride materials

Materials synthesis of carbon nitride has been attempted with co-implantation of carbon and nitrogen into thermally grown SiO₂. Following implantation of C and N ions to doses of 10¹⁷ cm^-2, thermal annealing of the implanted SiO₂ sample was conducted at 1000 °C in an N₂ ambient. As evidenced in Fourier transform infrared measurements and X-ray photoelectron spectroscopy, different bonding configurations between C and N, including C-N single bonds, CN double bonds and C≡N triple bonds, were found to develop in the SiO₂ film after annealing. Chemical composition profiles obtained with secondary ion mass spectroscopy were correlated with the depth information of the chemical shifts of N1s core-level electrons, allowing us to examine the formation of C-N bonding for different atomic concentration ratios between N and C. X-ray diffraction and transmission electron microscopy showed no sign of the formation of crystalline C₃N₄ precipitates in the SiO₂ film after post-implantation annealing.