Preparation and characterization of copper nitride films at various nitrogen contents by reactive radio-frequency magnetron sputtering

The semiconducting Cu₃N films were successfully deposited on glass substrates by reactive radio-frequency magnetron sputtering in a mixture gas of nitrogen and argon. The influence of nitrogen content in a fixed total sputtering gas flow on the preferential crystalline orientation, the mean crystalline grains size, the electrical resistivity, and the optical energy gap of as-deposited films were investigated. X-ray diffraction analysis shows that the films were polycrystalline Cu₃N and the preferential orientation is greatly affected by the N₂ content. All the Cu₃N films have smooth surfaces with dense and continuous microstructure. The electrical resistivity and the optical energy gap of these as-deposited Cu₃N films were measured to be in the range of 1.51 × 10²-1.129 × 10³ Ω cm, and 1.34-1.75 eV, respectively.