Copper nitride thin films prepared by radio-frequency reactive sputtering

Abstract

Copper nitride thin films were obtained by the reactive sputtering method. A metallic copper target was sputtered in nitrogen gas with radio-frequency (rf) magnetron sputtering equipment. Highly [100]-oriented polycrystalline films of the cubic anti-ReO3 structure were obtained. Films with a lattice constant above 3.868 Å were conductors, while films with a lattice constant below 3.868 Å were insulators. The resistivity of conducting films was 0.5–3×10−2 Ω cm. The insulating films showed an optical energy gap of 1.3 eV, while the conducting films showed a smaller value which decreased with decreasing resistivity.