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

Abstract

A sintered Ti13Cu87 target was sputtered by reactive direct current (DC) magnetron sputtering with a gas mixture of argon/nitrogen for different sputtering powers. Titanium-coppernitrogen thin 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 by X-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-crystallite cubic anti rhenium oxide (anti ReO3) structures of titanium doped Cu3N (Ti:Cu3N) and nanocrystallite face centered cubic (fcc) structures of copper. Scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM/EDX) were used to determine the film morphology and atomic titanium/copper ratio, respectively. The films possess continuous and agglomerated structure with an atomic titanium/copper ratio (∼ 0.07) below that of the original target (∼ 0.15). The transmittance spectra of the composite films were measured in the range of 360 nm to 1100 nm. Film thickness, refractive index and extinction coefficient were extracted from the measured transmittance using a reverse engineering method. In the visible range, the higher absorption coefficient of the films prepared at lower sputtering power indicates more nitrification in comparison to those prepared at higher sputtering power. This is consistent with the formation of larger Ti:Cu3N crystallites at lower sputtering power. The deposition rate vs. sputtering power shows an abrupt transition from metallic mode to poisoned mode. A complicated behavior of the films' resistivity upon sputtering power is shown.

Samarium oxide thin films deposited by reactive sputtering: Effects of sputtering power and substrate temperature on microstructure, morphology and electrical properties

“…However, the resistivities of Sm 2 O 3 thin films are much higher than the resistivity of bare n type silicon substrate; this implies that there exists an insulating layer. The conductivity and resistivity are correlated to the scattering from dislocations, impurities inside the crystallite and the potential barrier due to the intra-crystallites boundary effect and scattering through the nano-crystallite boundary [46]. As maintained in XRD and AFM explanation, the crystallinity, grain size and RMS of the deposited films are almost improved with sputtering power and substrate temperature.…”

Nitrification of Reactively Magnetron Sputter Deposited Ti-Cu Nano-Composite Thin Films

“…The presence of N neutrals reflected [30] from the single TiCu bi-component surface and impinging on the growing film with sufficient energy (due to large throw distance) can produce atomic scale heating in addition to substrate temperature which decompose the metastable Ti:Cu 3 N nano-crystallites to copper and escaped nitrogen [31]. This phenomenon becomes more significant at substrate temperature of 150˚C), because unbound N atoms out-diffuse from Ti:Cu 3 N crystallite into intercrystallite boundaries.…”

“…The refractive index n and the extinction coefficient k as well as the thickness d of polycrystalline nitrided Ti-Cu thin films on thick quartz substrate were studied. They were determined from transmittance data only using PUMA approach and code described by Birgin et al [41] used in our previous work [25,26,31]. Poelman et al [42] have reviewed and tested PUMA approach and shown it to produce excellent estimate of optical constants of thin films.…”

“…The electrical conduction of films grown as the phase mixture (composite) of Ti:Cu 3 N nano-crystallite and Cu nanoparticle might follow the effective medium theory. Three simultaneous conduction mechanisms Ti:Cu 3 N semiconducting conduction, Cu metallic conduction and tunneling through crystallite boundary play important roles in carrier transport [31]. The nanocomposite resistivity is correlated to scattering dislocation inside crystallite (intra-crystallite boundary effect), scattering from potential barrier due to intercrystallites boundary effect and scattering through nanocrystallite boundary (size effect) [31].…”

Effect of Nitrogen Partial Pressure on Reactive Magnetron Sputtering From Ti13Cu87 Metalloid Target: Simulation of Chemical Composition

“…3 and increases, as the nitrogen partial pressure ratio increases due to a lower scattering from nitrogen species than that of argon species in plasma during the mass transport between the target and the substrate. Rahmati et al [14][15][16] deposited Ti:Cu 3 N thin films using the reactive DC magnetron sputtering from a Ti 13 Cu 87 target and found that the atomic Ti:Cu ratio in as-deposited thin films (≈ 0.07) was less than that of the original target (≈ 0.15). Also, they indicated a good agreement between experimental results and the T a b l e 2.…”