scholarly journals Tantalum-Titanium Oxynitride Thin Films Deposited by DC Reactive Magnetron Co-Sputtering: Mechanical, Optical, and Electrical Characterization

Coatings ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 36
Author(s):  
Daniel Cristea ◽  
Ioana-Laura Velicu ◽  
Luis Cunha ◽  
Nuno Barradas ◽  
Eduardo Alves ◽  
...  

The possibility to tune the elemental composition and structure of binary Me oxynitride-type compounds (Me1Me2ON) could lead to attractive properties for several applications. For this work, tantalum-titanium oxynitride (TaTiON) thin films were deposited by DC reactive magnetron co-sputtering, with a –50 V bias voltage applied to the substrate holder and a constant substrate temperature of 100 °C. To increase or to decrease in a controlled manner, the Ti and Ta content in the co-sputtered films, the Ti and Ta target currents were varied between 0.00 and 1.00 A, in 0.25 A steps, while keeping the sum of the currents applied to the two targets at 1.00 A. The reactive gases flow, consisting of a nitrogen and oxygen gas mixture with a constant N2/O2 ratio (85%/15%), was also kept constant. The single-metal oxynitrides (TaON and TiON) showed a low degree of crystallinity, while all the other co-sputtered films revealed themselves to be essentially amorphous. These two films also exhibited higher adhesion to the metallic substrate. The TaON film showed the highest hardness value (14.8 GPa) and the TiON film a much lower one (8.8 GPa), while the co-sputtered coatings exhibited intermediary values. One of the most interesting findings was the significant increase in the O content when the Ti concentration surpassed the Ta one. This significantly influenced the optical characteristic of the films, but also their electrical properties. The sheet resistivity of the co-sputtered films is strongly dependent on the O/(Ta + Ti) atomic ratio.

2018 ◽  
Vol 9 ◽  
pp. 119-128 ◽  
Author(s):  
Kristjan Kalam ◽  
Helina Seemen ◽  
Peeter Ritslaid ◽  
Mihkel Rähn ◽  
Aile Tamm ◽  
...  

Thin solid films consisting of ZrO2 and Fe2O3 were grown by atomic layer deposition (ALD) at 400 °C. Metastable phases of ZrO2 were stabilized by Fe2O3 doping. The number of alternating ZrO2 and Fe2O3 deposition cycles were varied in order to achieve films with different cation ratios. The influence of annealing on the composition and structure of the thin films was investigated. Additionally, the influence of composition and structure on electrical and magnetic properties was studied. Several samples exhibited a measurable saturation magnetization and most of the samples exhibited a charge polarization. Both phenomena were observed in the sample with a Zr/Fe atomic ratio of 2.0.


2010 ◽  
Vol 159 ◽  
pp. 133-136 ◽  
Author(s):  
Biliana Georgieva ◽  
Irena Podolesheva ◽  
Georgi Spasov

Thin films (40-60 nm) prepared by co-evaporation of Sn and TeO2 were studied as ethanol gas sensors. In the as-deposited state, the films thus obtained are amorphous and consist of mixed Te and Sn oxides, doped with Te, Sn, and/or SnTe (depending on the atomic ratio between Sn and Te (RSn/Te)), due to interaction between the two substances during the co-deposition. After stepwise thermal treatment of films with RSn/Te ≈ 2.3 up to 360oC (by 40oC steps, for 15 minutes at each temperature) nanocrystalline films, built up of a mixture of SnO2, TeO2 and unstoichiometric Sn oxide were obtained. The Pt-doping was realized by thermal evaporation in a separate vacuum cycle, after the annealing. To study the film composition and structure as well as the volume distribution of the elements different electron microscopy techniques (TEM, SAED) and analytical methods (EDS in SEM, AES) were applied. The sensitivity towards ethanol vapours was investigated as a function of the substrate temperature (T) in the range from 20oC to 200oC. High sensitivity has been observed for Pt-doped films at T = 120oC. No cross sensitivity to relative humidity (RH [%]) was observed at this temperature. Further improvement of the sensitivity could be obtained by optimization of the thermal processing, Pt-doping and working temperature.


2010 ◽  
Vol 93-94 ◽  
pp. 541-544
Author(s):  
K. Limwichean ◽  
S. Porntheeraphat ◽  
Win Bunjongpru ◽  
P. Panprom ◽  
A. Pankiew ◽  
...  

In this report, we present sputtered zinc oxide (ZnO) thin films grown with different argon (Ar) and oxygen (O2) gas-timing sequence. Metallic zinc (Zn) with 5N-purity was used as a sputtering target, while Ar and O2 of 6N-purity were used as the bombard and reactive gases, respectively. The crystalline orientation, surface morphology, chemical composition, optical and electrical properties of deposited ZnO thin films were determined by XRD,AFM and UV-VIS measurement, respectively. The XRD result implied that deposition ZnO thin films at different O2 gas-timing control corresponded to the (002) plane of hexagonal ZnO structure at 2Ө = 34.4◦. Furthermore, when the reactive time of O2 was increased, the transmittance of ZnO thin films exhibited the energy gap increase from ~2.95 to ~3.18 eV, whereas the surface roughness was found to decrease. Finally, ZnO thin films were oxidized after the deposition.


2002 ◽  
Vol 720 ◽  
Author(s):  
Costas G. Fountzoulas ◽  
Daniel M. Potrepka ◽  
Steven C. Tidrow

AbstractFerroelectrics are multicomponent materials with a wealth of interesting and useful properties, such as piezoelectricity. The dielectric constant of the BSTO ferroelectrics can be changed by applying an electric field. Variable dielectric constant results in a change in phase velocity in the device allowing it to be tuned in real time for a particular application. The microstructure of the film influences the electronic properties which in turn influences the performance of the film. Ba0.6Sr0.4Ti1-y(A 3+, B5+)yO3 thin films, of nominal thickness of 0.65 μm, were synthesized initially at substrate temperatures of 400°C, and subsequently annealed to 750°C, on LaAlO3 (100) substrates, previously coated with LaSrCoO conductive buffer layer, using the pulsed laser deposition technique. The microstructural and physical characteristics of the postannealed thin films have been studied using x-ray diffraction, scanning electron microscopy, and nano indentation and are reported. Results of capacitance measurements are used to obtain dielectric constant and tunability in the paraelectric (T>Tc) regime.


2011 ◽  
Vol E94-C (2) ◽  
pp. 157-163 ◽  
Author(s):  
Masakazu MUROYAMA ◽  
Ayako TAJIRI ◽  
Kyoko ICHIDA ◽  
Seiji YOKOKURA ◽  
Kuniaki TANAKA ◽  
...  

2020 ◽  
Author(s):  
Elbruz Murat Baba ◽  
Jose Montero ◽  
Dmitrii Moldarev ◽  
Marcos V. Moro ◽  
Max Wolff ◽  
...  

<p>We report preferential orientation control in photochromic gadolinium oxyhydride (GdHO) thin films deposited by a two-step process. Gadolinium hydride (GdH<sub>2-x</sub>) films were grown by reactive magnetron sputtering, followed by oxidation in air. The preferential orientation, grain size, anion concentrations, and photochromic response of the films are strongly dependent on the deposition pressure. GdHO films show preferential orientation along the [100] direction and exhibit photochromism when synthesized at deposition pressures up to 5.8 Pa and. The photochromic contrast is larger than 20 % when the films are deposited below 2.8 Pa with 0.22 H<sub>2</sub>/Ar flow ratio. We argue that the degree of preferential orientation defines the oxygen concentration which is known to be a key parameter for photochromism in rare-earth oxyhydride thin films. The experimental observations described above are explained by the oxidation-induced decrease of the grain size as a result of the increase of the deposition pressure of the sputtering gas. </p>


Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1409
Author(s):  
Ofelia Durante ◽  
Cinzia Di Giorgio ◽  
Veronica Granata ◽  
Joshua Neilson ◽  
Rosalba Fittipaldi ◽  
...  

Among all transition metal oxides, titanium dioxide (TiO2) is one of the most intensively investigated materials due to its large range of applications, both in the amorphous and crystalline forms. We have produced amorphous TiO2 thin films by means of room temperature ion-plasma assisted e-beam deposition, and we have heat-treated the samples to study the onset of crystallization. Herein, we have detailed the earliest stage and the evolution of crystallization, as a function of both the annealing temperature, in the range 250–1000 °C, and the TiO2 thickness, varying between 5 and 200 nm. We have explored the structural and morphological properties of the as grown and heat-treated samples with Atomic Force Microscopy, Scanning Electron Microscopy, X-ray Diffractometry, and Raman spectroscopy. We have observed an increasing crystallization onset temperature as the film thickness is reduced, as well as remarkable differences in the crystallization evolution, depending on the film thickness. Moreover, we have shown a strong cross-talking among the complementary techniques used displaying that also surface imaging can provide distinctive information on material crystallization. Finally, we have also explored the phonon lifetime as a function of the TiO2 thickness and annealing temperature, both ultimately affecting the degree of crystallinity.


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