Papers by Keyword: Reactive Sputtering

Abstract: The structure evolution and mechanical behavior of the reactive DC magnetron sputtered complex concentrated (or compositionally complex) nitride RM-TiZrHf-N_y coatings with variable nitrogen stoichiometry with RM = V, Nb, and Ta were compared with the reference (TiHfZr)-N_y coatings over a wide range of nitrogen concentrations. Despite the concentrations of the refractory metals deviated from equimolar concentration, homogeneous solid solutions with cubic structures were present in all coatings. Their mechanical properties depended on nitrogen concentration and RM type. The maximum values of hardness (~43 GPa) and indentation modulus (~530 GPa) were achieved in the reference TiZrHf-N_y coatings with (near-) stoichiometric composition. The levels of properties in the coatings with V, Nb, or Ta additions were ~10 % lower and the differences among them were within the scatter of measurements. Thus, the synergy effect from the incorporation of the additional refractory metals into the TiZrHf sub-lattice on mechanical properties was not confirmed.

Abstract: The VN thin films were deposited on glass and Al₂O₃ substrates using reactive magnetron sputtering with a vanadium target in an Ar/N₂ mixed atmosphere. The deposition process was carried out at a substrate temperature of 25 °C and a sputtering power of 250 W. VN thin films were systematically prepared on glass substrates by varying the N₂/(Ar+N₂) ratio to 25%, 33%, 42%, and 56%. The results demonstrated that all as-deposited films consistently exhibited a face-centered cubic (FCC) NaCl-type crystal structure, regardless of the N₂/(Ar+N₂) ratio. Notably, the crystallization phase remained stable even when annealed at temperatures ranging from room temperature to 400 °C. As the nitrogen content increased, the resistivity of the films decreased, and the temperature coefficient of resistance (TCR) shifted toward smaller values. At a nitrogen content of 56%, the film exhibited the lowest resistivity of 63 μΩ-cm, along with a TCR of-460 ppm/°C. Furthermore, the resistivity demonstrated good stability, with only a 3% variation observed over one month.

Abstract: Technological advancements and changing global needs drive deposition techniques, widely used for altering surface properties of components. The crosswinds from global technological advancements in the mobility and power sectors have piqued the interest in sustainable renewable energy tapping devices. Thin aluminium oxide (Al2O3) films are highly valued for various applications in the manufacturing industry, such as cutting tool coatings, optics, energy, and microelectronics. A novel and facile approach has been adopted in the present work to fabricate an oxide-based thin film on a BK7 glass substrate. The aluminium oxide film is deposited by reactive radio frequency (RF) magnetron sputtering by impinging adequate argon to oxygen ratio in a high vacuum environment. Furthermore, Al2O3 is deposited by an alumina target with the same deposition technique, and the results were compared. A digital thickness monitor (DTM) is used to assess the thickness of the deposited film for both processes. The films were first characterized by X-ray diffraction and then analysed by other characterization methods, including Scanning Electron Microscopy, Atomic Force Microscopy, Tribometer and Nanoindentation, and UV-visible spectroscopy. The results indicated that Al2O3 deposited by reactive RF magnetron sputtering performed better in terms of surface morphology, UV-absorbance, nanohardness, and wear resistance and is therefore, more reliable and sustainable when compared with non-reactive RF magnetron sputtering.

Abstract: The NbN thin films were deposited onto glass and Al₂O₃ substrates using reactive magnetron sputtering, employing a niobium target sputtered with a mixture of Ar and N₂ gases. The investigation focused on the phase structures, microstructures, and electrical properties of the NbN thin films under various deposition powers and annealing temperatures. The results indicated the presence of a face-centered cubic (FCC) crystal structure in the as-deposited films at a power of 125 W. Interestingly, the crystallization phase remained unchanged within an annealing temperature range from room temperature to 500 °C. It was observed that the resistivity of the NbN thin films increased with higher nitrogen content, while the temperature coefficient of resistance (TCR) showed a tendency towards more negative values as the nitrogen content rose. Notably, at a nitrogen content of 9%, the film exhibited the lowest resistivity of 273 μΩ-cm with a TCR of -240 ppm/°C.

Abstract: Titanium chromium nitride (TiCrN) thin films were deposited on Si substrates by reactive DC unbalanced magnetron sputtering from the Ti-Cr mosaic target. The effect of substrate-to-target distances (d_st) on the structure of TiCrN thin films were investigated. The crystal structure, microstructure, thickness, roughness and chemical composition were characterized by glancing angle X-ray diffraction (GAXRD), field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM) and energy dispersive X-ray spectroscopy (EDS) technique, respectively. The results showed that, all the as-deposited films were formed as a (Ti,Cr)N solid solution. The as-deposited films exhibited a nanostructure with a crystal size less than 65 nm. The crystal size of all plane were in the range of 36.3 – 65.7 nm. The lattice constants were in the range of 4.169 Å to 4.229 Å. The thickness and roughness decrease from 500 nm to292 nm and 3.6 nm to 2.2 nm, respectively, with increasing the substrate-to-target distance. The chemical composition, Ti, Cr and N contents, of the as-deposited films were varied with the substrate-to-target distance. The as-deposited films showed compact columnar and dense morphology as a result of increasing the substrate-to-target distance.

Abstract: In this work, we investigated V₂O₅ thin films prepared by a DC pulse reactive magnetron sputtering at ambient conditions. The effects of oxygen flow rates during the film deposition and post annealing in air atmosphere were explored. The V₂O₅ thin films were sputtered from vanadium target onto silicon wafer and glass slide substrates at room temperature. The as-deposited V₂O₅ thin films were annealed at 200°C under air atmosphere. The films were then examined for their crystallinity, physical microstructures, and optical transmission. The crystallinity and morphology of the films were investigated by grazing incident x-ray diffraction, atomic force microscopy, and field-emission scanning electron microscopy. The optical transmission was determined by UV-Vis Spectrophotometer. The results showed that the as-deposited films were amorphous, whereas the post annealed films indicated V₂O₅ phase in all samples. The increase in the oxygen flow rates during the deposition led to the decrease in the deposition rate, film thickness, and film surface roughness. In addition, the oxygen flow can increase the average transmission of the V₂O₅ thin films. The effects of the annealing treatment of the optical transmission spectra will be discussed.

Abstract: The paper presents the research work carried out in order to optimize the technology and reactive magnetron sputtering system used for the deposition of hard, multielemental, multiphase coatings. On the basis of a model of dynamic pressure developed and validated by us, regulatory structures for dynamic pressure inside the deposition chamber were designed and implemented. By using this optimization, extensive experiments involving nanostructured (Ti, Al, Si)N coatings, with a thickness of approx. 2 μm, were carried out. Using TEM microscopy, SAED and Vickers microhardness characterizations the results of deposition system optimization on the microstructure and microhardness of thin films were investigated.

Abstract: The article reports on the aspects of reactive deposition ultra-thin TiO_x films (50 nm) by means of dual magnetron system with mirror and closed magnetic field (B field) configurations. The hysteresis effect of electrical discharge characteristics and oxygen partial pressure P(O₂) are presented. The dual magnetron with closed B field configuration has less hysteresis peculiarities and transits back to metallic deposition mode at higher O₂ flow rate (Q). The deposition rates don’t depend on B field configuration and correlate with changing of P(O₂) and discharge voltage. The refractive spectra and energy of band gap, which are measured by UV-visible spectrophotometry and ellipsometry (λ=632.8 nm) methods, have strong dependence on Q(O₂).

Abstract: Yttria-stabilized zirconia (YSZ) films were deposited on Y₂O₃/Ni-5at.%W substrates serving as the barrier layers for coated conductors by reel-to-reel direct-current (D.C.) magnetron reactive sputtering. The deposition parameters, such as the substrate temperature and tape moving speed, were systematically investigated. X-ray diffraction analysis confirmed that optimized YSZ/Y₂O₃ buffer layers showed excellent in-plane and out-of-plane textures. Atomic force microscope revealed a smooth, dense and crack-free surface. The subsequent CeO₂ cap layer and 1μm-thick YBa₂Cu₃O_7-δ film sequentially prepared, showing the critical current density J_c under 77K, self-field of 1.4MA/cm².

Abstract: We report on the fabrication of bottom gate thin film transistors with indium oxide (In2O3) thin films as the active channel layers. The films were deposited on SiO2/Si substrate at room temperature by direct current (DC) magnetron sputtering. The ITO films were used as source and drain electrodes. The In2O3 films were structurally characterized by x-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The results revealed that the films were amorphous in nature. Electrical measurement has revealed that the devices operate as an n-channel enhancement mode and exhibit an on/off ratio of 10⁶. The threshold voltage is-3V and the channel mobility on the order of 22.3 cm2/Vs has been determined.