The influence of NH3 flow rate on the microstructure and oxidation properties of a-Si-C-N:H films prepared by PECVD technology

•The a-Si-C-N:H film become more dense with increasing NH3 flow rate.•The film oxidation become more serious with increasing NH3 flow rate.•The carbon atoms tend to bond with each other during the film deposition.•The N atoms mainly bonded with C atoms and O atoms mainly bonded with Si atoms.•The film oxidation is caused by Si dangling bonds and the carbon nanoclusters.