The evolution of Cu3N films irradiated by femtosecond laser pulses

► The metastable copper nitride films were studied by femtosecond laser pulses irradiation. ► The femtosecond laser process generates the metal precipitation of Cu in the copper nitride matrix at the nanometer scale. ► The microstructure, morphology and electrical resistance of Cu3N films present regular changes with the decrease of laser power density. ► A delicate balance of ablated and decomposed contributions to determine the optimal decomposed rate of Cu3N films induced by femtosecond laser. ► The resistance value of some samples is low enough to serve as a conductive layer for microelectronic application after irradiation.