Two Crystal Phases of C₃N₄ Found in Carbon Nitride Films Prepared by Ion Implantation

CN_x films prepared by high dose ion implantation and post-annealing were studied by Auger electron spectroscopy, x-ray photoelectron spectroscopy and x-ray diffraction. A nearly uniform CN_x layer was formed. Carbon and nitrogen were found covalently bonded in the films. X-ray diffraction results showed that two crystal phases of C₃N₄, β-C₃N₄ and p-C₃N₄, have been formed in the matrix of carbon.