Papers by Keyword: DC Reactive Magnetron Sputtering

Abstract: Multi-functional thin films have gained increasing importance in a decorative application. Among the available material, titanium nitride (TiN) thin film is interesting due to its golden color and mechanical resistance. Beside their properties, the corrosion property of TiN films is mainly considered in order to extend the life time. In this work, the TiN thin films were deposited on 3x3 cm² Si(100) substrates by dc reactive magnetron sputtering technique. The effects of N₂ partial pressure (P_N2) on deposited film properties such as microstructure, surface morphology, color, mechanical and corrosion properties were investigated. We found that the crystal structure of the TiN films exhibit the (200) preferred orientation. The color of TiN films change from gold-yellow to gold-red colors by increasing of N₂ partial pressure that could be explained by Drude model. The TiN films have smoother surface when the N₂ partial pressure increases. Standard corrosion tests in artificial sweat solution show the corrosion current density (i_corr) in the range between 0.25 to 4.25 mA/cm² and the polarization resistance increases with increasing of N₂ partial pressure. The highest hardness of the film is approximately 40 GPa with elastic modulus of 340 GPa. We conclude that N₂ partial pressure corelates with color, mechanical property and corrosion resistance of TiN films, which were optimized to use in decorative application.

Abstract: In this study, we investigate a facet of the fabrication process of chromium nitride (CrN) film intended as a protective coating for pineapple blades. CrN thin films were deposited on unpolished stainless steel substrates (AISI304) by DC reactive magnetron sputtering in Ar+N₂ gases. In principle, the proportion of nitrogen partial pressure to the total pressure in the sputtering process should have considerable effects on the CrN film’s chemical composition, its crystal structure, its hardness, and its corrosion resistance. We tested this supposition out by using several different nitrogen partial pressures in the sputtering process and observed the films deposited. The coatings were deposited at five different nitrogen partial pressures of 4.0x10^-4 mbar, 8.0x10^-4 mbar, 1.2x10^-3 mbar, 1.6x10^-3 mbar, and 2.0x10^-3. The deposition times were controlled to achieve 5-µm thick films in each deposition. The films were analyzed by several analytical methods, such as X-ray diffraction (XRD), scanning electron microscope, micro-hardness and potentiostat in pineapple juice. The XRD spectra of the films showed face-centered cubic structure with (200) preferred orientation, positively identifying them as Cr₂N and CrN thin films. The calculated d-spacing and lattice parameter of the CrN films increased with increasing nitrogen partial pressure; the ranges were 0.283–0.287 nm and 0.491-0.497 nm, respectively. The cross-section morphology of the CrN films reveals the columnar grain growth with a high density. The crystal structure and the grain texture correspond with the hardness property. The films corrosion potential, an indicator of their corrosion property, was varied from -0.14 to -0.05 volts with varying nitrogen pressure. The most corrosion resistant and the good hardness were the film fabricated at the nitrogen partial pressure of 1.2x10^-3 mbar.

Abstract: Titanium dioxide (TiO₂) nanothin films were deposited on unheated substrate, the glass slide and Si-wafer, by DC reactive magnetron sputtering with different substrate-target distance (d_st), in range of 8 to 14 cm. The structural, surface morphology and transmittance spectrum of TiO₂ thin films were characterized by grazing-incidence X-ray diffraction (GI-XRD), atomic force microscopy (AFM) and spectrophotometer, respectively. XRD results show that as-deposited TiO₂ films with short substrate-target distance have only anatase crystal structure corresponding to the anatase in (101) and (200) plane, and turn to be amorphous with long substrate-target distance. The thickness and roughness varied from 50 nm to 142 nm and 1.6 nm to 3.5 nm, respectively. The as-deposited TiO₂ films exhibited high visible transmittance. The optical constants of the films, refractive index (n) and extinction coefficient (k), were calculated by Swanepoel method, at 550 nm, was about 2.43 - 2.76 and 0.082 - 0.187, respectively. The energy band gap (E_g) of the as-deposited TiO₂ films in the range of 3.20 - 3.25 was observed.

Abstract: Titanium dioxide (TiO₂) thin films have been deposited on Si-wafer and glass slide by DC reactive magnetron sputtering technique at different O₂ gas flow rates. The crystal structure was characterized by grazing-incidence X-ray diffraction (GIXRD), surface morphology was analyzed by atomic force microscopy (AFM) and disinfection of surfaces by photo catalytic oxidation with TiO₂ and UV light irradiation. The results showed that, from GIXRD results, all as-deposited TiO₂ films have crystal structure of TiO₂ corresponding to the A(101) and A(200). AFM results showed that the film thicknesses increase from 183 nm to 238 nm with increasing of O₂ gas flow rate, while the film roughness was in range of 4.8 nm to 5.9 nm. The as-deposited anatase TiO₂ thin film in this work can kill the bacteria when expose to the UV light.

Abstract: Abstract: Alumina (Al2O3) thin films were deposited over glass and Si substrates by DC reactive magnetron sputtering at an oxygen partial pressure of 0.03 Pa. The presence of aluminium and oxygen was confirmed using x-ray photoelectron spectroscopy and the films were found to be nearly stoichiometric or oxygen rich at a sputtering power of 70 W and 60 W, respectively. The as-deposited films were found to be amorphous. Subsequent annealing experiments in vacuum revealed that crystallisation started at 550oC and increased thereafter at higher annealing temperatures for those films deposited at a sputtering power of 70 W. The topography of the as-deposited and annealed films was analyzed by Atomic force microscopy and a progressive increase in the rms roughness of the films was observed with increase in the annealing temperature and the results are discussed

Abstract: Transparent conductive ZnO:Zr thin films with different thicknesses were fabricated on glass slides by DC reactive magnetron sputtering from Zn:Zr targets consisting of Zn disk and Zr metallic chips in Ar+O₂ mixture gas. X-ray diffraction, four-point probe measurements, UV–vis spectrophotometers and thin film thickness tester were employed to characterize the structure, electrical and optical properties of ZnO:Zr films, respectively. The experimental investigations indicate that film thickness has an important effect on the crystal structure, optical and electrical properties of the deposited films.

Abstract: Due to their unique physical and chemical properties, vanadium oxide thin films have become a hot research topic. In the present work, Vanadium oxide thin films were prepared by DC reactive magnetron sputtering at different oxygen partial pressure and thermally annealed in Ar atmosphere at 500°C for 2 hours. The microstructure, transmittance, optical band gap, resistivity, and temperature coefficient resistance (TCR) were measured. The results suggest that increasing of oxygen partial pressure can obviously improve the optical and electric properties

Abstract: The ZnO and ZnO:Ce thin films were prepared by DC reactive magnetron sputtering. The structure, surface morphology, optical and photoluminescence properties of ZnO:Ce thin films were investigated. The XRD results indicated that all the samples exhibited a hexagonal wurtzite structure. The surface morphology of the films was sensitive to the Ce concentration. All the films had a higher average transmittance (more than 85%) in the visible region and a strong absorption near the band-edge of ZnO. The photoluminescence properties of the Ce-doped ZnO thin films were also studied. Blue emissions were observed from the ZnO:Ce thin films. Our results indicated that the photoluminescence properties of ZnO thin films doped with low Ce concentration were related to the intrinsic transition of Ce3+ ions. However, when the Ce concentration increased, Zni also played an important role.

Abstract: In this work, CrN/NbN nanometer multi-layers were deposited on the metal substrates by a dual-target DC reactive magnetron sputtering system. X-ray diffraction, Scanning Electron Microscope and Energy Dispersive Spectrometer were used to analysis the phase composition, crystal structure, surface morphology, fracture morphology and elemental composition of thin films. Micro Hardness Tester and wear-resistant experiments were used to test the hardness and wear properties of the films.

Abstract: In this study, multilayers of TiN/NbN were deposited by d.c. magnetron sputtering on die steel substrates. The structure, morphology and nano-hardness were assessed using X-ray diffraction, atomic force microscopy (AFM), stylus profiler (XP-2 stylus profiler) and nanoindentation, respectively. Wear tests were performed on pin-on-disk configuration and dry sliding conditions, at 5N load by using hardened steel ball. The result shows TiN with highly (111) preferred orientation. On mechanical properties, Young’s modulus and hardness values increase for layers number increase. At 64 layers films had the highest nano-hardness, Young’s modulus values. The TiN/NbN multilayer films presented changes in its morphology becoming more granulated and density after heating up to 500°C. A significant decrease in friction coefficient has been achieved for TiN/NbN multilayers against steel ball.