Structural and optical properties of copper nitride thin films in a reactive Ar/N₂magnetron sputtering system

Abstract

Copper nitride films were prepared on glass and silicon substrates by reactive direct current magnetron sputtering at various N2-gas partial pressures at room temperature. The N2 partial pressure influenced the structural, electrical and optical properties of the deposited films. The X-ray diffraction measurement showed the phase change of the preferred orientation of Cu3N planes of samples from Cu-rich (111) planes to N-rich (100) planes. The surface resistivity of glass substrate Cu3N films was between 1675 and 58 200 Ω/cm2 and for silicon substrate films surface resistivity was between 13.2 and 2380 Ω/cm2. As is observed surface resistivity strongly affected by structures of the films. Deposition rate was influenced by the amount of argon gas since they are heavier than nitrogen atoms changes from 43 nm/min to 26 nm/min. Calculated band gap energy of the samples show a sharp enhancement from 1.4 eV to 1.95 eV by increasing nitrogen content in working gas.