Chemical analysis of a-CNx thin films synthesized by nanosecond and femtosecond pulsed laser deposition

An ArF excimer laser (22ns, 193 nm) and a hybrid dye/excimer laser system ( 500 fs, 248 nm) are used to deposit amorphous carbon nitride films at room temperature by ablation of a graphite target in nitrogen atmosphere. The ch emical composition and structure of the films is characterized by X-ray pho toelectron spectroscopy. In the nanosecond case, the nitrogen content incre ases with reactive gas pressure up to 45 atomic %, while in the subpicoseco nd case it remains below 7 at. %. When processed with nanosecond pulses, th e films' nitrogen content steeply increases with fluence up to a maximum. T he target-to-substrate distance has only minor influence on the amount of n itrogen incorporated into the films. The dependence of the carbon-carbon an d carbon-nitrogen bond configurations on the processing parameters is also given.