Published online by Cambridge University Press: 12 December 2012
A sintered Ti13Cu87 bi-component target was sputtered by reactive DC magnetron sputtering in nitrogen ambient under various sputtering powers. Ti included Cu3N (Ti:Cu3N) thin films were deposited on Si (1 1 1), KBr (potassium bromide), quartz and glass slide substrates. Crystalline phases of the films were identified by X-ray diffraction (XRD) technique. Crystalline quality and phase stability are strongly dependent on sputtering power. Formation of copper vacancies in Cu3N cell substituted by Ti atoms and subsequent excess of interstitial nitrogen (N-rich) result in lattice constant expansion. Bonding environment in these films was obtained from fourier transform infrared (FTIR) spectroscopy. Surface morphology of the films that were studied by a scanning electron microscope (SEM) indicates a granular structure. Atomic Ti:Cu ratio of Ti:Cu3N films, determined by energy dispersive X-ray (EDX) spectroscopy, is less than that of original target. Optical study was performed by Vis-near IR transmittance spectroscopy. Film thickness, refractive index and extinction coefficient were extracted from the measured transmittance using pointwise unconstrained minimization approach. The TiCu3N films are direct semiconductor with bandgap energy with the range of 2.79–3.34 eV. Ti incorporation and subsequent N-rich have a significant role in bandgap widening and lattice constant expansion. The films electrically show quasi-metallic behavior.