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 (10(-5) Pa) and in N-2 ambient gas (1-100 Pa) using a XeCl excimer laser (lambda = 308 nm, tau(FWHM) = 30 ns) with a fluence of 5 J/cm(2), 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 N-2 pressure strongly influenced the BCN formation and, consequently, the properties of the deposited films. (C) 1998 Elsevier Science B.V.