Fabrication and optical constants of amorphous copper nitride thin films prepared by ion beam assisted dc magnetron reactive sputtering

A novel implementation of simultaneous use of ion beam assisted deposition (IBAD) and reactive dc magnetron sputtering of a metal copper target in pure nitrogen plasma to produce thin films of amorphous copper nitride (a-CuxN) is described. This technique produced amorphous thin films, very stable and optically comparable with crystalline copper nitride (Cu3N) films produced by several deposition methods. The work also reports on the optical characteristics and determination of the optical constants of this material following a recently introduced method of calculations, PUMA. The optical energy gap 2.03 ± 0.0342 eV deduced from the transmittances measurements is slightly higher than that reported for the Cu3N films over a range of 1.2–1.9 eV.