A new approach for the growth of copper nitrides thin films by thermal evaporation using nitrogen as source gas

Abstract

Thin films of copper nitride (Cu3N) were successfully synthesized by thermal evaporation method. The Cu powder was evaporated on glass substrate ina horizontal glass tube furnace having central temperature 1000 °C under a vacuum of 10−2 m Torr for 25 mints. After evaporation of Cu powder, the temperature of tube furnace was set as 300 °C and nitrogen gas was flown into a tube furnace at a rate of 100 sccm for different time durations of 2–8 h respectively. XRD data demonstrated that only one XRD peak (53.916°) of Cu3N phase was observed for sample prepared using nitrogen gas flow time duration 2 h. But as we increased the time duration for nitrogen flow, three diffraction peaks at 2theta 23.005°, 32.9° and 38.228° were observed, which are related due to the (100), (111) and (200) planes of Copper Nitride. The intensity of Cu3N related diffraction peaks was found to be increased with increasing the time duration which suggested that good crystal quality was observed in the sample having the time duration of 8 h. We argued that for large time durations of nitrogen gas flow, the surface diffusion of the adatom is increased causes the nitrogen atoms react with free Cu atoms to form Cu3N thin films. Raman spectroscopy data demonstrated peaks of Cu3N structure at 487 and 608 cm−1 for samples prepared using 6 and 8 h time duration. SEM data further confirmed our XRD and Raman data that sample prepared using 8 h time duration has best crystal quality. The XPS and FTIR measurements were also performed on 8 h annealed sample to further justified the presence of Cu3N structure.