Boron carbon nitride films deposited by sequential pulses laser deposition

In this paper, we report the successful growth of c-BCN thin films by reactive pulsed laser ablation RPLA.of a rotating target 3 Hz.formed of two semidisks: one of h-BN and the other one of graphite, with the substrate at room temperature. The irradiations were performed in vacuum 10y5 Pa.and in N2 ambient gas 1–100 Pa. using a XeCl excimer laser ls308 nm, t FWHMs30 ns.with a fluence of 5 Jrcm2. Series of 10,000 pulses at a repetition rate of 10 Hz were directed to target. Different analysis techniques pointed out the synthesis of h-BCN and c-BCN. Microhardness measurements at the deposited films evidence high values up to 2.9 GPa. Secondary ion mass spectroscopy SIMS.profiles showed the presence of layers of 600–700 nm thickness, with uniform concentrations of B, C and N in the films. Uniform signals of BN and CN, which are related to the BCN bond, are also present. X-ray photoelectron spectroscopy XPS.studies pointed out the BCN compound formation. The deconvolution of B 1s recorded spectra evidenced a strong peak centered at 188 eV.assigned to B bonded in BC2N; the N 1s and C 1s spectra also confirm the BCN formation. Transmission electron microscopy TEM. and selected area electron diffraction SAED.analysis evidenced the presence of c-BCN phase with crystallites of 30–80 nm. and h-BCN phase as well. The N2 pressure strongly influenced the BCN formation and, consequently, the properties of the deposited films. q1998 Elsevier Science B.V.