Optical characterization of BCN films deposited at various N2/Ar gas flow ratios by RF magnetron sputtering

We present the deposition and optical characterization of amorphous thin films of boron carbonitride (BCN). The BCN thin films were deposited in a radio frequency magnetron sputtering system using a B4C target. Films of different compositions were deposited by varying the ratio of argon and nitrogen gas in the sputtering ambient. X-ray photoelectron spectroscopy was used to perform surface characterization of the deposited films and a change in composition with nitrogen flow ratio was observed. The effect of gas flow ratios on the optical properties of the films was also investigated. It was found that the transmittance of the films increases with nitrogen incorporation. The optical band gap of the films ranged from 2.0 eV to 3.1 eV and increased with N2/Ar gas flow ratio except at the highest ratio.