Synthesis of copper nitride films doped with Fe, Co, or Ni by reactive magnetron sputtering

Copper nitride (Cu3N) and Fe-, Co-, and Ni-doped Cu3N films were prepared by reactive magnetron sputtering. The films were deposited on silicon substrates at room temperature using pure Cu target and metal chips. The molar ratio of Cu to N atoms in the as-prepared Cu3N film was 2.7:1, which is comparable with the stoichiometry ratio 3:1. X-ray diffraction measurements showed that the films were composed of Cu3N crystallites with anti-ReO3 structure and adopted different preferred orientations. The reflectance of the four samples decreased in the wavelength range of 400–830 nm, but increased rapidly within wavelength range of 830–1200 nm. Compared with the Cu3N films, the resistivity of the doped Cu3N films decreased by three orders of magnitude. These changes have great application potential in optical and electrical devices based on Cu3N films.