DC Magnetron Sputtering Process Research Articles

Oxygen plasma treatment WO3 nanorods for Improvement H2S gas sensing

Herein, the oxygen (O2) plasma has been used to post-treat tungsten oxide (WO3) nanorods to improve the sensing performance of the H2S gas sensor. The reactive DC magnetron sputtering process with the glancing-angle deposition (GLAD) technique was used to prepare the WO3 nanorods. After deposition, the WO3 nanorod thin films were treated with O2 plasma at different treatment power from 100 – 200 W. The physical structure of as-deposition and treated WO3 nanorod thin films was investigated crystal structure and morphology by grazing incident X-ray diffraction (GIXRD), field-emission scanning electron microscope (FE-SEM), and high-resolution transmission electron microscope (HRTEM). The result indicated that the WO3 nanorod structure transformed to the monoclinic polycrystalline phase. FE-SEM and HRTEM observed slight changes in the shape of the WO3 nanorods. The H2S sensing properties were measured at 10 ppm at 150 – 350°C operating temperatures. At an operating temperature of 200 °C, the response to H2S of O2 plasma treated WO3 nanorods is increased by a factor of 5 – 15, and the maximum response to H2S is 15. The results showed that the O2 plasma treatment process improved the sensing response of the WO3 nanorods.

Temperature dependent interaction of hydrogen with PdAg nanocomposite thin films revealed by in-situ synchrotron XRD

PdAg nanocomposite alloy thin films were synthesized using a DC magnetron sputtering process to study the structural changes that occur in the alloy film during the process of hydrogenation and dehydrogenation at different temperatures. The atomic composition of the nano-composite film is 88 at % Pd and 12% at Ag, as determined by the EDAX analysis. In-situ synchrotron X-ray diffraction (XRD) has been used to monitor the subtle structural changes that occurred throughout the hydrogenation and dehydrogenation cycles at an interval of 10 s. This aspect has not been addressed so far. In-situ XRD studies reveal that the XRD peak shifts towards a lower angle due to the lattice expansion in the alloy due to hydrogenation. The change in peak shift is found to be different for different temperatures. The present study also shows no hysteresis during the hydrogen absorption and desorption processes. In addition, the results show that (i) the phase segregation has been observed at 250 °C, (ii) the peak shift during the hydrogenation process at higher temperatures is not significant, whereas the peak shift throughout the process is more rapid and pronounced at ambient temperature.

Near substrate surface plasma characteristics of ZnO film deposition in DC reactive magnetron sputtering with water vapor

The effect of varying the water vapor content in a DC magnetron sputtering process was investigated for zinc oxide film formation. The plasma parameters near the substrate surface were measured using a single Langmuir probe, and the deposited films were characterized using X-ray diffraction, X-ray reflectivity, optical transmittance, and 4-point probe methods. In the region near the substrate surface, the addition of water changes the plasma properties, and the measured plasma parameters showed the changes corresponding to the transition in the film growth mechanism from Zn to ZnO. Depositing at 40% water content resulted to a highly transparent film with a ρ of 1.20 Ω cm. The band gap of films deposited at 40%–100% water content ranged from 3.36 to 3.34 eV, which matches the expected shallow hydrogen donor doping in ZnO.

Investigation and Band Gap Analysis of Pulsed Dc Magnetron Sputtered Diamond‐Like Carbon to Enhance Contact‐Electrification and Durability of Triboelectric Nanogenerators

AbstractThis work details the triboelectric characteristics of diamond‐like carbon (DLC) film where a proportioned sp3:sp2 bond ratio is engineered through a patented pulsed DC magnetron sputtering process to achieve a durable commercial energy harvesting material. A triboelectric nanogenerator (TENG) is fabricated by creating the triboelectric interface between DLC and PTFE. The presence and synchronization of σ – σ and σ – π bonds between DLC‐PFTE contact surface amplify the electronic cloud overlap between their atoms leading to an enhancement of the triboelectric surface charge density. The inherent hardness and reduced friction achieved through DLC and PTFE respectively prevent the mass transfer, and consequent power loss upon consecutive mechanical contact and achieves a stable electric power output of 141 mW m−2. The DLC durability achieved with PTFE in TENG demonstrates its significant potential as low frequency (1 – 10 Hz) energy harvesting devices and self‐/low‐power electronic devices and sensors. The paper uniquely contributes to a better understanding of the triboelectrification mechanism by insightfully detailing the band‐to‐band transition of electrons between the PTFE and DLC tribo‐interface, as well as discussing gap and frequency limitation of the tribo‐pair on the triboelectric charge yield, storage, transfer, and on the friction layer electric field.

Improvement of the Wear Resistance and Corrosion Properties of CrN Films on Oxynitriding-Treated Vanadis 23 High-Speed Steel by the DC Magnetron Sputtering Process

This study coated CrN films onto oxynitriding-treated Vanadis 23 high-speed steel using the DC magnetron sputtering process of the PVD technique. The experimental parameters include various deposition temperatures (275, 300, 325, and 350°C), a bias of -25 V, a power of 100 W, a gas flow rate of 45/30 (Ar/N2) sccm, and a deposition time of 2.5 h. The research results show that Vanadis 23 high-speed steel formed an effective oxynitriding layer with a depth of about 50 μm after the oxynitriding treatment, and the surface hardness increased to 1100 HV0.05. Furthermore, when the coatings were deposited at 325°C, the CrN coatings possessed an obvious columnar crystal structure, the highest hardness (13.4 GPa), and the highest elastic modulus (159.7 GPa). In addition, the CrN coating had the best wear properties (the lowest specific wear rates were 1.07×10-6 and 1.33×10-6 mm3·m-1·N-1 under the loads of 2 N and 4 N, respectively) and good corrosion resistance (corrosion current was 8.90×10-5 A·cm-2, and polarization resistance was 822.11 Ω·cm2 in a 3.5 wt% NaCl solution).

Air and Vacuum Annealing Effect on the Highly Conducting and Transparent Properties of the Undoped Zinc Oxide Thin Films Prepared by DC Magnetron Sputtering

In this study, we aim to investigate the effect of zinc interstitials (Zni) and oxygen vacancies (VO) on the ZnO electrical conductivity. ZnO films were synthesized via DC magnetron sputtering process using pure Zn target in gases mixture of Ar/O2 = 80/17.5 (sccm). In order to improve the optical and electrical prosperities, the obtained films were subjected to air and vacuum annealing treatment. Several techniques such as field emission scanning electron microscopy (FESEM), Grazing Incidence X-ray Diffraction (GIXRD), Raman spectroscopy, photoluminescence spectroscopy (PL) and UV-visible were used to study the influence of heat treatment on structural and physical properties of ZnO films. Electrical conductivity of ZnO thin films was determined by measuring the sheet resistance and thickness of the films. XRD results confirm the synthesis of annealed ZnO films of the hexagonal structure with a preferential orientation along the (002) plane. The average crystallite size is altered between 22.6 to 28.4 nm dependent on the plan orientation of the ZnO film. Morphology and crystallinity of the ZnO structure could efficiently control the transmittance, electrical resistivity and optical band gap. As deposited ZnO film showed a lower electrical resistivity of 2.72×10-3 Ωcm due to the Zn-rich conditions. Under vacuum annealing, a combination of low resistivity (1.17×10-2 Ωcm) and better optical transmittance (87 %) are obtained. ZnO films developed in this study with high transmittance and low resistivity and good electro-optical quality supports their use in transparent and conductive electrode applications. The plan presentation was visualized using Vesta, with the lattice parameter set as follows: a = b = 3.249 Å; c = 5.207 Å; α = β = 90°; γ = 120°. Based on the construction and optimization of primitive cells, the supercells were constructed and then optimized. Finally, (002) and (103) planes were cut and the planar supercell structure was constructed. In order to make a plane representation for the solid bulk with 10 Å of thickness.

Synthesis of Al Thin Films with High Optical Transmittance by DC Magnetron Sputtering Process Parameter Optimization

Nanostructured Al thin film with higher optical transmittance and electrical conductivity has intensive applications in solar cells and optical and microelectronic devices. This experimental-based research study has optimized the DC magnetron sputtering deposition parameters (sputtering power, sputtering current, voltage, and working gas pressure) for Al thin film deposition to obtain the highest optical transmittance and lower sheet resistance. Optical transmittance, surface roughness, film thickness, sheet resistance, grain size, and surface morphology were characterized using UV-vis-NIR spectroscopy, surface profiler, spectroscopic ellipsometry, four-point probe, and FE-SEM, respectively to determine the effects of sputtering process parameters on Al films’ different properties. Experimental investigations reveal that electrical conductivity, surface roughness, grain size, and deposition rate increase with increasing of sputtering power at certain working gas pressure. At the optimized condition (sputtering power 80 W, working gas pressure 5 mTorr, deposition time 5 min and ambient temperature), the relatively higher optical transmittance in visible region 96%, moderate sheet resistance 0.196 ohm/square and lowest average surface roughness 2.86 nm were obtained for Al thin film. After all, this research study will help to understand the best Al film deposition parameters in terms of optical transmittance and electrical conductivity for future research and industrial applications.

Influence of Heat Treatment on Corrosion Resistance of Sn/Mg Films Formed by PVD Method on Hot-Dip Galvanized Steel

Double layers composed of Sn and Mg, each 0.8 μm thick, were fabricated on a hot-dip galvanized steel (8.4 μm) sheet using DC magnetron sputtering and post-annealing processes. With an increase in temperature, the surface morphologies were agglomerated with each other. Additionally, Sn/Mg mixture sites, including an intermetallic compound of Mg2Sn, were formed at 190 °C and locally clustered at 220 °C. In the salt-spray test, the corrosion resistance of the Sn/Mg film prepared at 190 °C was 960 h, which is longer than that at non-heat for 528 h or 220 °C for 480 h. In the polarization test, the Sn/Mg film formed at 190 °C displayed a lower corrosion current density of 1.07 μA/cm2 and potential of 1.62 V/SSCE than those at non-heat or 220 °C.

Evaluation of Adhesion Properties of Thin Film Structure through Surface Acoustic Wave Dispersion Simulation.

A theoretical simulation study of the dispersion characteristic of the surface acoustic wave (Rayleigh wave) was conducted by modeling the adhesion interlayer with stiffness coefficients to evaluate the bonding properties of nano-scale thin film structures. For experimental validation, a set of thin film specimens were fabricated—637 nm, 628 nm, 637 nm, 600 nm, and 600 nm thick titanium (Ti) films were deposited on silicon (Si) (100) substrate using a DC Magnetron sputtering process with DC power from 28.8 W, 57.6 W, 86.4 W, 115.2 W, and 144 W. The thicknesses of the Ti films were measured using a scanning electron microscope (SEM). Surface acoustic wave velocity for each of the manufactured thin film specimens was measured by using a V(z) curve technique of a Scanning Acoustic Microscope. The measured velocity, transducer frequency, and thickness of the film were applied to dispersion characteristic simulation for a given stiffness coefficient to calculate adhesion strength of each specimen. To verify the simulation result, the adhesion force of each specimen was measured using a nano-scratch test and then compared with the calculated values from the dispersion characteristic simulation. The value of adhesion strength from the dispersion characteristic simulation and the value of adhesion force of the nano-scratch test were found to have a similar tendency according to the process variable of the thin film. The results demonstrated that the adhesion strength of a thin film could be evaluated quantitatively by calculating the dispersion characteristics with the adhesion interlayer stiffness model.

Self-Supporting Ultrathin DLC/Si3N4/SiO2 for Micro-Pressure Sensor

In this study, we firstly reported a micro-pressure sensor based on self-supporting diamond-like carbon (DLC)/Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> /SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> films with total thickness of 785 nm, where the DLC film was fabricated by a facile DC magnetron sputtering process. Particularly, the DLC film was selected as a hybrid sensitive and structural material due to its superior mechanical, piezoresistive properties and stability under harsh environment. Results showed that the sensitivity of the integrated sensor could reach <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$5.3\,\,\times10$ </tex-math></inline-formula> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-5</sup> /kPa within the pressure range of 0–60 kPa, together with the nonlinearity and the hysteresis was 5.7% FS (full scale) and 0.8% FS, respectively (at 20 °C). Most importantly, without any thermal insulation package, the sensitivity only changed slightly within ±7.0% even the temperature varied dramatically from −20 °C to 100 °C. Such excellent performance of the sensor was mainly originated from the good stability of atomic bond structure in DLC films, which was confirmed by the variable-temperature XPS test. In addition, the signal could be further compensated by the DLC thermal compensation resistor in which the temperature coefficient of resistance (TCR) was about −1247.3 ppm/°C. These results bring forward a promising strategy to fabricate the micro-pressure sensor with high structural sensitivity, stability as well as lightweight design for micro-electromechanical system (MEMS) used in harsh applications.

Wear and Corrosion Resistance of CrN Films on Oxynitriding-treated Vanadis 8 Tool Steel &lt;i&gt;via&lt;/i&gt; the DC Magnetron Sputtering Process

This research coated CrN films on oxynitriding-treated Vanadis 8 tool steel using the DC magnetron sputtering process of the PVD technique. The experimental parameters include different gas flow rates (Ar/N2 was 20/20, 24/16, 28/12, and 32/8, respectively), with a bias of −50 V, power of 100 W, deposition temperature of 300°C, and deposition time of 180 min, respectively. The experimental results show that Vanadis 8 tool steel can form an effective oxynitriding layer with a depth of about 50 µm after the oxynitriding treatment, and the surface hardness increased to about 1400 HV0.05. Furthermore, the duplex coating layers exhibited optimal properties when the CrN films treated at an appropriate gas flow rate of Ar/N2 was 24/16. Meanwhile, according to XRD analysis, the coating layer has a relatively high content of CrN composition, as well as the best wear resistance (the lowest specific wear rate when the loads of 2 N and 4 N were 2.05 × 10−5 and 1.56 × 10−5 mm3·m−1·N−1) and good corrosion resistance (in a 3.5 wt% NaCl environment, Icorr = 3.05 × 10−4 A·cm−2, Rp = 362.52 Ω·cm2). Overall, this study reveals that the CrN/oxynitriding duplex surface treatment could effectively improve the wear and corrosion properties of Vanadis 8 tool steel.

Influence of substrate type and film thickness on the failures of Zr-based thin-film metallic glass under nanoscratch

Nanoscratch experiments under constant and ramp loading conditions are performed to investigate the delamination, and spallation characteristics of Zr-based thin-film metallic glass (Zr-based TFMG, Zr65Cu15Al10Ni10). TFMGs with different film thickness = 200, 500, 1000 nm are deposited over hard and soft substrates via DC magnetron sputtering process. Coefficient of friction (COF) is measured to be less about 0.03 regardless of scratch mode and maximum normal load. The critical load for thin film delamination and spallation reveals that the deformation and failure mechanism of Zr-based TFMG significantly change with film thickness and substrate type. The failure mechanism is characterized by observing the scratch grooves via optical and scanning electron microscopes (SEM). The adhesion energy between thin film and soft substrate is calculated based on Burnett and Rickerby model, and an increase in adhesion energy with interfacial layer thickness is reported.

Structural properties of Ag-CuO thin films on silicon prepared via DC magnetron sputtering

In this paper, 3% and 5 % of Ag doped copper oxide (CuO) deposited onto silicon substrates as thin film using the DC magnetron sputtering process under Ar gas. The sputtering deposition was performed by using a power of 75 W. XRD results conformed a good crystallinity of the synthesized Ag/CuO nanoparticle thin films. SEM analysis indicated to all the prepared samples are having a quasi-spherical shape. Based on AFM analysis, the roughness of prepared samples determined and found the high roughness of 3% Ag/CuO sample that attitude to have it a less mean crystal size compated with 5% Ag/CuO, which calculated using Scherrer equation. The EDX spectra indicated the high purities for the prepared sample befor and after deposted on Si as substrate

Interface-driven magnetic anisotropy of epitaxial [formula omitted] thin films

The effect of film-substrate interface on the magnetic anisotropy (MA) of epitaxial Fe4N thin films grown on single crystalline MgO (100) and MgO (111) substrates has been studied in this work. Both samples were grown simultaneously using a reactive dc magnetron sputtering process at a substrate temperature of 250°C. Single phase Fe4N samples were found to grow epitaxially on (100) and (111) oriented MgO substrates as confirmed from out-of-plane x-ray diffraction and in-plane ϕ-scan measurements. The MA of (100) and (111) oriented Fe4N samples was measured using longitudinal magneto-optical Kerr effect (MOKE). In spite of being grown simultaneously, the MA of both these samples was found to be different. Secondary ion mass spectroscopy and x-ray reflectivity measurements revealed the formation of a dense layer at the film-substrate interface. The MA of this dense layer along with the MA of Fe4N has a dramatic effect on magnetic reversal depending on the orientation of the substrate. Further, from the MOKE measurements, the difference in the magnetization switching processes was found to depend on the microstructure and orientation of Fe4N thin films.

The effect of deposition times in DC-magnetron sputtering on micromorphology of TiO2 thin films.

TiO2 thin films have been prepared by DC-magnetron sputtering process with various deposition times (8, 14, 16, and 20 min) and the micromorphology of their surface has been investigated by means of multifractal analysis. As the main purpose of the manuscript, the topography of all samples are examined by atomic force microscopy (AFM) through the Mountains Map® Premium software which characterizes motifs of significant peaks and pits through stereometric data by the watershed segmentation algorithm. In addition, multifractal features of samples provide deeper insight into texture characteristics and used as the supplementary of the results.

Transport properties of n-type Cux-TiyCz thin film semiconductor at different Cu/TiC ratios

Cu-TiC thin films possess a unique combination of optical and electrical properties. In this work, Cux-TiyCz thin film is deposited on Si (1 0 0) substrate by DC magnetron sputtering process. The Hall results revealed n-type conductivity and carrier concentration in the order of 1018 m−3, when Cu/TiC atomic percentage ratio (r) is varied between 2.14 and 7.5. The optical band-gap varies between 2.67 and 1.97 eV at different values of r. The film exhibits minimum Hall mobility (240 cm2/Vs)) and electrical resistivity (9.3 Ω.m) at an optimum ratio (r ∼ 5) in room temperature. The increasing crystallite size as a function of the Cu/TiC ratio is observed in the polycrystalline films with Cu and TiC phases. The average particle size has also increased in nanometre dimensions at r ∼ 5. The stoichiometric value close to Cu-TiC3 has culminated in future coating and electronic design applications.

Electrical and infrared responses of n-VO2/p-GaAs heterojunctions based on VO2 phase transition properties

In this investigation, high-quality VO2 films were prepared on p-GaAs wafers by DC magnetron sputtering and post-annealing process. The results indicate that the optimum annealing temperature and time of the sample are 2 h and 420 °C with the excellent rectification characteristics originated from the n-VO2/p-GaAs interface before the occurrence of semiconductor-to-metal phase transition in VO2, which can be explained by the thermal electron emission model. The device’s threshold voltage at 30 °C and 60 °C corresponds to 7.5 and 6 V. The responsivity of the as-fabricated photon detector under 980 and 1310 nm laser illumination was 0.013 and 0.022 A W−1 at an applied bias of 3 V as well as 0.0025 and 0.0048 A W−1 at zero bias, respectively. The NIR transmittance decreases with increasing voltage and temperature due to the combination of voltage and temperature to induce VO2 phase transition. The results will be beneficial to explore and improve the IR photon detector based on VO2 and provide ideas for new optoelectronic devices with phase transition characteristics.

Magnetic and magnetotransport study of Si/Ni multilayers correlated with structural and microstructural properties

Influence of Si layer spacer on the magnetic and magnetotransport properties of the Si/Ni multilayers has been studied. The study is performed by investigating a series of [Si(tSi)/Ni(30Å)]20 multilayers prepared by DC magnetron sputtering process. The structural and microstructural studies suggest that the effective crystallites size increases with the decrease in tSi. The cross sectional TEM data reveal that the Si/Ni multilayers with tSi ≤ 10 Å are of discontinuous form. The magnetization (M20kOe) obtained at 20 kOe increases as tSi decreases and reaches towards the bulk value of Ni. This increase in M20kOe is due to the increase in effective size of the Ni nanocrystallites. The magnetotransport parameters such as saturated anomalous Hall resistance, anomalous Hall coefficient, Hall sensitivity and magnetoresistance ratio are found to gradually increase within 100 Å ≤ tSi ≤ 30 Å and then sharply increase till tSi = 10 Å due to surface and interface scattering. These parameters decrease when tSi further reduces down to 5 Å which is beyond the percolation threshold. The maximum enhancements of about 33 times in anomalous Hall resistance and 24 times in anomalous Hall coefficient are found at tSi = 10 Å when compared with the multilayers having tSi = 100 Å. The skew scattering is the dominant mechanism which is responsible for the anomalous Hall effect phenomena in the Si/Ni multilayers. The Si/Ni multilayers also show anisotropic magnetoresistance.

Effect of RF/DC Magnetron Sputtering Process Parameters for Improving Efficiency of Solar PV Cell

The biggest disadvantage of solar cells is that it has low solar power conversion efficiency typically 14%. So as to improve the power conversion performance, several attempts was made by researchers and once such technique is to reduce the reflection by providing textures on the solar cells. This texture will reduce the reflectance and thereby increase the solar power conversion efficiency. In this work, an investigational study was conducted to improve an energy efficiency of solar PV cells. Here Cu, Ag, Al was deposited for metallization purpose at specific places by using RF and DC magnetron sputtering process. The input parameters such as power, deposition time and substratum temperature were optimized during the sputtering process and the corresponding coating thickness, optical properties and surface topography were investigated. The coating thickness and surface roughness were increased as power increased from 15W to 45W. Average surface roughness (Ra) of 6nm and was obtained at the optimum power of 45W and deposition rate of 5-7 mins. The surface morphology and topography was characterized by using SEM and AFM which shows uniform coating with spherical shaped with densely packed nanostructures with increase in grain size were observed and elemental composition were confirmed by using EDAX. The absorption and reflection were investigated by using UV-VIS-NIR spectrometer indicates that the optical absorption increased from 1.2% to 1.68% at the wavelength range from 250 to 314nm. The reflection was reduced from 13.4% to 3.67% and the conversion efficiency was increased from 14.22% to 16.63%. This paper reports the complete experimental details, results and analysis.

Supercapacitive properties of manganese nitride thin film electrodes prepared by reactive magnetron sputtering: Effect of different electrolytes

Abstract Development of metal nitride-based thin film binder-free electrodes is a rapidly emerging area of research for the development of supercapacitors. The manganese nitride (Mn3N2) binder-free thin film electrodes were prepared using DC magnetron sputtering process. X-ray diffraction and the Raman spectroscopy characterization confirmed the formation of the tetragonal phase of Mn3N2 thin film. Field emission scanning electron microscopy revealed that the Mn3N2 particles are in nanoscale range and the particles with pyramidal shape are distributed uniformly on the surface of the film. Further, the Mn3N2 electrodes were examined by cyclic voltammetry and galvanostatic charge-discharge measurements to investigate the supercapacitive properties. The electrochemical measurements were performed on Mn3N2 deposited on conducting stainless steel substrates in different electrolytes (KOH, KCl and, Na2SO4 at 1 M concentration). The effect of various electrolytes on the areal capacitance, cycling stability, capacitance retention of the Mn3N2 electrodes was investigated. The Mn3N2 electrodes show high areal capacitance of 118 mF cm−2 for KOH, 68 mF cm−2 for KCl and 27 mF cm−2 for Na2SO4 at a scan rate of 10 mV/s. Moreover, the Mn3N2 electrodes indicated excellent cycling stability with capacitance retention of 98.5%, 89% and 83% for KOH, KCl, and Na2SO4, electrolytes respectively after 4,000 cycles. A comparative study on the electrochemical supercapacitive properties of the Mn3N2 electrode in different aqueous electrolytes is reported for the next generation electrochemical energy storage devices.