Silicon oxynitride thin films synthesised by the reactive gas pulsing process using rectangular pulses

► SiON films were synthesised by RGPP using oxygen rectangular pulses. ► O2 introduction results in Si target potential decay due to its favoured adsorption. ► O/N ratio depends on frequency of sputtering mode alternation. ► Over a certain frequency, oxidised steady-state prevails resulting in SiO2 formation.