Reactive DC Magnetron Sputter Deposited Titanium-Copper-Nitrogen Nano-Composite Thin Films with an Argon/Nitrogen Gas Mixture

<正> A sintered Ti13Cu87 target was sputtered by reactive direct current （DC） magnetronsputtering with a gas mixture of argon/nitrogen for different sputtering powers.Titanium-copper-nitrogenthin films were deposited on Si （111）,glass slide and potassium bromide （KBr） substrates.Phase analysis and structural properties of titanium-copper-nitrogen thin films were studied byX-ray diffraction （XRD）.The chemical bonding was characterized by Fourier transform infrared（FTIR） spectroscopy.The results from XRD show that the observed phases are nano-crystallitecubic anti rhenium oxide （anti ReO3） structures of titanium doped Cu3N （Ti:Cu3N） and nanocrystalliteface centered cubic （fcc） structures of copper.Scanning electron microscopy and energydispersive X-ray spectroscopy （SEM/EDX） were used to determine the film morphology and atomictitanium/copper ratio,respectively.The films possess continuous and agglomerated structure withan atomic titanium/copper ratio （～0.07） below that of the original target （～0.15）.The transmittancespectra of the composite films were measured in the range of 360 nm to 1100 nm.Filmthickness,refractive index and extinction coefficient were extracted from the measured transmittanceusing a reverse engineering method.In the visible range,the higher absorption coefficientof the films prepared at lower sputtering power indicates more nitrification in comparison to thoseprepared at higher sputtering power.This is consistent with the formation of larger Ti:Cu3Ncrystallites at lower sputtering power.The deposition rate vs.sputtering power shows an abrupttransition from metallic mode to poisoned mode.A complicated behavior of the films' resistivityupon sputtering power is shown.