HF-CVD of B, C, N containing layers on various substrates by the decomposition of Triethylborazine

In the BCN phase triangle many interesting compounds are located, e.g. h-BN, c-BN, BC 2N, graphite and diamond. For layers with composition in this area interesting qualities can be expected. To fix the B:C:N stoechiometry 2,4,6-Triethylborazine (C 6H 18B 3N 3) was used and decomposed in a hot-filament equipment. Pre-carburised Ta-filaments and hydrogen or argon for the gas atmosphere were used. Untreated, etched and diamond coated WC–Co hardmetal inserts were used as substrates. The deposition parameters filament temperature (1800–2200 °C), precursor flow rate and gas atmosphere were varied. The layer growth rates increased with the precursor flow rate and showed less influence of the substrate material. Layer morphology was of the pyrolytic type. When the layers became thick they tended to eliminate from the substrate. Due to the atomic hydrogen produced at the filament the deposition rate decreased in case of H 2/Ar atmosphere compared to the experiments in argon atmosphere. This can be explained by etching reactions of the atomic hydrogen. Due to the etching reactions of the atomic hydrogen the IR-spectra also looked different. Nevertheless, it was not possible to identify a cubic phase from the IR or XRD measurements.