Nitrogen ion implantation into the amorphous C-N films prepared with ion beam assisted deposition

In order to further increase the nitrogen content of the amorphous C-N films prepared with ion beam assisted deposition (IBAD), nitrogen ion implantation at 50 keV has been performed with the films. The films were characterized by Auger electron spectroscopy (AES), Rutherford backscattering spectrometry (RES), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Both AES and RES results show that the N concentration of the implanted films can be increased up to a saturated value of about 43 at.%. Although this saturated value is still lower than the stoichiometric N concentration of beta-C3N4, TEM observation indicates that crystalline beta-C3N4 with a dimension of about 30 nm has been grown at a dose of 10(18) ions cm(-2). It is also demonstrated by XPS that nitrogen ion implantation can result in more sp(3) bonding character in the C-N films.