Chemical analysis of pulsed laser deposited a-CNx films by comparative infrared and X-ray photoelectron spectroscopies

Amorphous carbon nitride films are deposited at room temperature on silicon substrates by ArF excimer laser (193nm) ablation of a graphite target in nitrogen atmosphere. By tuning the process parameters, fine control of the carbon–carbon and carbon–nitrogen bond configuration is achieved in a broad range as followed by X-ray photoelectron spectroscopy (XPS) and infrared (IR) absorption spectroscopy. Based on the comparative and quantitative analysis of changes in measured IR versus XPS spectra as a function of reactive gas pressure, laser fluence and target-to-substrate distance, and on a critical review of the existing interpretation of IR data, an assignment of the components of the broad band extending from 900 to 1900cm−1 in the IR spectra to specific carbon–carbon and carbon–nitrogen bond configurations is proposed.