PECVD synthesis and optical properties of BCXNY films obtained from N-triethylborazine as a single-source precursor

Thin films of boron carbonitride BCxNy were synthesized by plasma enhanced chemical vapor deposition using N-triethylborazine as a B-C-N-forming single source precursor. In this work, we investigated the effect of additional gases and temperature synthesis on the chemical composition of the BCxNy films. The plasma was activated via 40.68 MHz radio frequency. It was found by FTIR spectroscopy that the low temperature films (Tdep < 400 °C) are hydrogenated boron carbonitride BCxNy:H. It was shown by Raman spectroscopy that the films synthesized at high temperature (Tdep ≥ 600 °C) contain an additional phase of disordered carbon. The refractive index of the BCxNy films increased from 1.5 to 2.8 with increasing temperature of the synthesis. Low temperature films exhibit high transmittance values in the region from 400 to 3200 nm (transparency up to 93%). The optical band gap energy ranged from 1.2 to 4.9 eV for the films deposited under considered synthesis conditions.