Increasing Sputtering Power Research Articles

Synthesis and Characterization of Radio-Frequency-Sputtered Delafossite Copper Indium Oxide (CuInO2) Thin Films

The deposition of CuInO2 films was achieved for the first time through a dual-target RF magnetron sputtering technique using Cu and In2O3 targets. It is found that the sputtering power of the Cu target has a significant effect on the structural, morphological, and optical characteristics of the films. The sputtering power of Cu was varied from 5 W to 50 W while the sputtering power of In2O3 was held constant at 50 W. From the XRD analysis, it was confirmed that pure-phase CuInO2 was obtained at a Cu sputtering power of 5 W. XPS analysis revealed that Cu exists in the oxidation state of 1+ in the films sputtered with 5 W Cu, further confirming the successful synthesis of single-phase CuInO2. The oxidation states of Cu and In, full-width half maximum (FWHM), peak positions, satellite peak positions, and their respective binding energies have been elucidated through XPS analysis. Nanocrystalline growth was confirmed through SEM analysis performed on all the post-deposition annealed films. Further, it was observed that grain size increased from 18.49 nm to 63.34 nm as Cu sputtering power is increased from 5 W to 50 W. The optical studies were performed on the post-deposition annealed films in the 300–800 nm wavelength range. The optical transmission and the optical bandgap were found to decrease with an increase in the Cu sputtering power. The highest transmission of ∼75% and the highest bandgap of 3.62 eV was obtained for the films showing single-phase CuInO2.

Effect of Cu2O Sputtering Power Variation on the Characteristics of Radio Frequency Sputtered p-Type Delafossite CuCrO2 Thin Films

For the first time, the effect of Cuprous Oxide (Cu2O) sputtering power variation on the radio frequency sputtered Copper Chromium Oxide (CuCrO2) thin films was studied. In this work, the sputtering power of Cr2O3 was held constant at 200 W while the sputtering power of the Cu2O target was varied from 10 to 100 W. The films were subsequently annealed at 650 °C in N2 ambiance. The effects of Cu2O sputtering power variation on the structural, optical, and electrical properties of the films have been reported in this work. X-ray diffractometer (XRD) study revealed that the single-phase delafossite structure of CuCrO2 was only obtained at Cu2O sputtering power of 50 W. X-ray photoelectron spectroscopy (XPS) analysis further established the results of XRD study where Cu in 1+ oxidation state was identified in thin films obtained at 50 W of Cu2O sputtering power. The optical studies were conducted in this work on all the post-deposition annealed films in the wavelength range of 200–800 nm. The energy dispersive x-ray spectroscopy (EDS) study revealed a near stoichiometric composition ratio of 1:1.06 of Cu:Cr at% obtained in the films sputtered with 50 W of Cu2O sputtering power. The highest optical transmission of ~81% and the highest optical bandgap of 3.21 eV were observed for single-phase CuCrO2 thin films. The optical transmission and the optical bandgap were found to decrease with an increase in the Cu2O sputtering power. The electrical study performed on all the post-deposition annealed films revealed that the lowest resistivity of 0.652 Ω-cm was identified for single-phase CuCrO2 thin films obtained at 50 W of Cu2O sputtering power.

Manipulation of the Martensitic Transformation and Exchange Bias Effect in the Ni45Co5Mn37In13 Ferromagnetic Shape Memory Alloy Films

The martensitic phase transition and exchange bias effect of the Ni-Mn-based ferromagnetic shape memory alloys (FSMAs) Ni45Co5Mn37In13 (Ni-Co-Mn-In) films are investigated in this paper. The martensitic transformation properties of the Ni-Co-Mn-In alloy target material are manipulated by the process of electric arc melting, melt-fast quenching, and high-temperature thermal pressure. The Ni-Co-Mn-In alloy films with martensite phase transition characteristics are obtained by adjusting deposition parameters on the (001) MgO substrate, which shows a significant exchange bias (EB) effect at different temperatures. With increasing sputtering power and time, the film thickness increases, resulting in a gradual relaxation of the constraints at the interface between the film and the substrate (the interfacial strain decreases as the increase of thin film thickness), which promotes the martensite phase transition. Between zero-field cooling (ZFC) and field-cooled (FC) curve obvious division zone, the decrease of exchange bias field (HEB) and coercive force field (Hc) with an increase in test temperature is due to ferromagnetic (FM) interaction begins to dominate, resulting in a reduction of antiferromagnetic (AFM) anisotropy at the interface. The maximal HEB and Hc reach ~465.7 Oe and ~306.9 Oe at 5 K, respectively. The manipulation of the martensitic transformation and EB effect of the Ni-Co-Mn-In alloy films demonstrates potential application in the field of information and spintronics.

Manipulating the optoelectronic characteristic of AZO films by magnetron sputtering power

We investigated the effects of sputtering power on the structure, morphology, electrical and optical properties of AZO films. The results show that all the films show typical hexagonal wurtzite structure with preferred c-axis orientation. When the sputtering power is 120 W, the film has the smallest FHWH value and the largest grain size (24.33 nm), and the AZO thin films obtained the best conductivity, the electrical characteristic parameters are ρ = 3.25 × 10−3 Ω cm， N = 3.512 × 1019 cm−3, μH = 8.642 cm2V−1s−1, respectively. With the increase of sputtering power, the carrier concentration and hall mobility are increasing, which are directly related to the improvement of crystal quality, that is, the higher the crystal quality of the film, the better the conductivity. The average transmittance of all samples is above 80%, and the band gaps increase first and then decreased. This work implies that the application of controllable growth AZO transparent conductive film in photovoltaic devices.

Effect of sputtering power on the properties of TiN coatings deposited by the magnetron sputtering

In this work, the TiN coatings on Ti6Al4V and Si substrates were deposited by magnetron sputtering. The effect of sputtering powers on structure and mechanical properties of the TiN coatings was investigated. X-ray diffraction patterns displayed a single phase of face centered cubic structure. Scanning electron microscope observations found that the particle morphology of the TiN coatings changed from a leaf or flat-shaped structure to a tetrahedron faceted one, similar to a pyramid. The particle size and deposition rate increased with increasing sputtering power due to higher energy bombardment of ion gas to surface target. Furthermore, the highest hardness value (22,8 GPa ± 1,2 GPa) corresponds to the TiN coating deposited at 250 W power. Finally, the friction coefficient increased from 0,46 to 0,61 with increasing sputtering power from 150 to 300 W.

Nanoscale surface dynamics of RF-magnetron sputtered CrCoCuFeNi high entropy alloy thin films

High entropy alloy (HEA) thin films of CrCoCuFeNi are grown on stainless steel substrate using radiofrequency (RF) magnetron sputtering method at different sputtering times (30, 60 and 90 minutes), substrate temperatures (room temperature, 100 and 200 deg. Celsius) and RF powers (100, 150 and 200 W). The nanoscale morphology and topography of the thin films are obtained using an atomic force microscopy (AFM) method. The average surface roughness, interface width, fractal and multifractal characteristics of the films are presented. It is shown that the average surface roughness and interface width decrease with the time of deposition while considering the combination of the other factors. The autocorrelation and height-height correlation functions reveal that these surfaces are self-affine and exhibit fractal characteristics. The increase in sputtering power, with different combinations of time and temperature, is related to large fractal dimension and small lacunarity coefficient. The increase in substrate temperature (for different combinations with time and RF power) is shown to enhance the spatial roughness of the HEA thin films. A multifractal analysis undertaken using generalized fractal dimension, mass exponent against moment order and multifractal spectrum reveal that all the films have a multifractal character; and the films deposited at high temperatures and powers exhibit the strongest multifractal behaviour.

Effect of substrate temperature and RF power on the structural and optical properties of sputtered ZnO thin films

ZnO thin films have been deposited on glass substrates by radio frequency (RF) magnetron sputtering from a zinc oxide target in order to investigate the effect of RF power and substrate temperature on the properties of the deposited films. The structural and optical properties of the films were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), UV-Vis transmission spectra and photoluminescence (PL). All ZnO thin films exhibited diffraction peak of (002) corresponding to c-axis orientation and the film deposited at 450°C exhibited the larger grain size as a result of stress relaxation. It is observed that the increase in substrate temperature or sputtering power can facilitate the growth of ZnO in (100) and (101) direction. PL emission was obtained at UV and visible region for the excitation wavelengths of 280 nm and 390 nm respectively. PL study indicated that both the crystal quality and stoichiometry can influence the UV PL emission in ZnO thin films. Dependence of temperature and power on transmission spectra was studied and the optical band gap was calculated.

Microstructure, mechanical and tribological properties of gradient CrAlSiN coatings deposited by magnetron sputtering and arc ion plating technology

Three CrAlSiN coatings with gradient concentrations of Al and Si ascending from the transitional layer to the surface were prepared by a combined method of direct current magnetron sputtering and arc ion plating using linearly increasing sputtering power. Microstructure, mechanical and tribological properties of the three gradient coatings were studied. Results show that all coatings possess face-centered cubic CrN phase with small amounts of hexagonal close packed AlN phase. The preferential orientation of the gradient coatings evolves from (111) to (220) crystal plane as the linear ultimate power is enlarged from 1.2 kW to 2.8 kW. The hardness increases gradually with the linear ultimate power, while the adhesion strength and wear resistance of the three coatings decrease gradually. For all the three gradient coatings, slight oxidation occurs at the boundaries of the wear track. Abrasive wear is the main failure mode for the CrAlSiN coating with linear ultimate power of 1.2 kW and 2.0 kW, while exfoliation resulting from low crack resistance is the primary cause for the highest wear rate of the CrAlSiN coating with linear ultimate power of 2.8 kW.

Structural properties of sputter-deposited nanocrystalline Ni thin films

Abstract For this study, Ni thin films were deposited on a glass substrate by using 200, 300, and 400 W direct-current magnetron sputtering method for observing the effect of sputtering power on the structural properties of thin films. Grain size, crystallinity, orientation, and texture of the deposited thin films were observed and evaluated by X-ray diffraction (XRD) analysis. According to XRD analysis, all thin films presented crystalline atomic structure. Furthermore, the effect of texture on the structural properties were observed using strain analysis and grain sizes that were calculated by Scherrer’s method and Williamson-Hall analysis. The analysis revealed that the grain size of sputter-deposited thin films increased linearly with respect to the increasing sputtering power. Additionally, the elastic modulus and indentation hardness of the samples were measured by nanoindentation method, and the results were evaluated in terms of grain size and texture. The highest grain size, 7.30 nm, was observed on a 400 W sputter-deposited sample, which also had the highest elastic modulus and indentation hardness values as 98 and 3.6 GPa, respectively.

Optical and electrical properties of ITO/Metal/NiO triple-layer grown by PVD method: An experimental study

In this work, transparent conducting oxides (TCOs) comprising an ITO/Metal/NiO sandwich structure grown by sputtering and thermal evaporation in a vacuum are investigated. By exploiting the four-point probe measurements and optical spectrometry both optical and electrical characteristics of the fabricated ITO/Metal/NiO trilayers for diverse metals such as Au, Ag, and Cu are studied. Moreover, through X-ray diffraction and high-resolution scanning electron microscopy method the structural characteristics are fully examined. The results reveal that the type of innermost metal plays the main role in the optical and electrical behavior of the trilayers structure. An average transmittance of 73-62% range at visible wavelength and small resistivity of 2 × 10−4 Ω cm are achieved for a 10 nm thick Au interlayer. The sheet resistivity (Rs) of NiO drops drastically from 200 Ω (single NiO layer) to 1.2Ω for ITO/Cu/NiO structure. Moreover, an increase in sputtering power and film thickness increases the optical bandgap. The obtained results prove that physical vapor deposition (PVD) is a good method for producing par excellence TCO films with beneficial characteristics such as high transmittance and low resistivity.

Preparation and Characterization of p-Type Copper Gallium Oxide (CuGaO2) Thin Films by Dual Sputtering Using Cu and Ga2O3 Targets

For the first time, this research focuses on the deposition and characterization of radio frequency (RF) sputtered p-type CuGaO2 thin films using the dual-target sputtering technique with Cu and Ga2O3 targets. The sputtering power to the Cu target was varied from 5 W to 50 W while having the Ga2O3 sputtering power constant at 200 W. The deposited films were subsequently annealed at two different annealing temperatures of 800 °C and 900 °C in N2 ambiance. The effects of variation in Cu sputtering power and annealing temperature on structural, optical, and electrical properties of CuGaO2 thin films are reported in this work. Single-phase CuGaO2 was confirmed in films deposited with Cu sputtering power of 25 W by XRD analysis. XPS analysis revealed a near stoichiometric composition ratio of Cu:Ga in films deposited with Cu sputtering power of 25 W. The optical studies were performed in 200 nm–800 nm wavelengths on all the post-deposition annealed films. The optical transmission was found to decrease with an increase in Cu sputtering power. The optical bandgap was found to be between 3.3 and 4.6 eV. Single-phase CuGaO2 film was p-type with a resistivity of 60 Ω-cm. This resistivity value is one of the lowest ever reported values identified from CuGaO2 thin films.

Effects of preparation parameters on growth and properties of β-Ga2O3 film

The Ga2O3 films are deposited on the Si and quartz substrates by magnetron sputtering, and annealing. The effects of preparation parameters (such as argon–oxygen flow ratio, sputtering power, sputtering time and annealing temperature) on the growth and properties (e.g., surface morphology, crystal structure, optical and electrical properties of the films) are studied by x-ray diffractometer (XRD), scanning electron microscope (SEM), and ultraviolet-visible spectrophotometer (UV-Vis). The results show that the thickness, crystallization quality and surface roughness of the β-Ga2O3 film are influenced by those parameters. All β-Ga2O3films show good optical properties. Moreover, the value of bandgap increases with the enlarge of the percentage of oxygen increasing, and decreases with the increase of sputtering power and annealing temperature, indicating that the bandgap is related to the quality of the film and affected by the number of oxygen vacancy defects. The I–V curves show that the Ohmic behavior between metal and β-Ga2O3 films is obtained at 900 °C. Those results will be helpful for the further research of β-Ga2O3 photoelectric semiconductor.

Influence of Pulsed DC Sputtering Power on the Quality and Residual Stress of AlN Films on Si (100) Substrates

AbstractAluminum nitride (AlN) films are prepared on Si (100) substrates by pulsed direct current magnetron sputtering. The effect of sputtering power on the crystal quality, residual stress, surface morphology, and optical properties of AlN films is comprehensively studied using X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), atomic force microscope, and ellipsometer. It is found that the AlN film quality is strongly impacted by the sputtering power. When the sputtering power increases to 3 kW, the full width at half maximum of the AlN (002) rocking curve decreases to 2.66°. And the film crystal quality does not change significantly when the sputtering power exceeds 3 kW. Fourier transform infrared spectrum analysis shows that with increasing sputtering power, the compressive stress of AlN films first increases and then decreases. The high sputtering power also results in smoother surface and better optical performance for the AlN films. This work can serve as an important reference for growing high‐quality AlN films on cost‐effective silicon (Si) substrates via sputtering, which can facilitate the development and commercialization of III‐nitride based photonics and electronics on AlN‐on‐Si substrates.

Impact of samarium on the structural and physical properties of sputtered ZnO thin films

Zinc oxide (ZnO) thin films containing samarium (Sm) were prepared by radio frequency (RF) sputtering. The Sm was introduced to ZnO films at different RF sputtering powers. The structure of the prepared films has a hexagonal ZnO phase, and the presence of the Sm in the ZnO lattice led to a decrease in the crystalline nature. The average crystallite size values along the major plane (002) decreased with the increase in sputtering power on the Sm. Spherical grains were observed and their values increased from 74.1 nm for the base sample to 82.57 nm when the Sm sputtered at 70 W. After intercalating Sm in the ZnO lattice, the surface roughness was improved. The absorption edge of the samples shifted to a higher photon energy when the Sm increased from 2.51 to 4.33 at%. The linear and non-linear optical parameters and photoluminescence are discussed in terms of the Sm content.

Study on the resistivity and infrared emissivity of TiNx films at different sputtering power

TiNx films with low infrared emissivity were prepared using DC reactive magnetron sputtering technique. The influence of sputtering power (50, 80, 100, and 200 W) on the morphology, structure, adhesion force, resistivity and infrared emissivity was investigated systematically. The thickness of the prepared TiNx films was in the range of 381–987 nm. The films grew with preferred orientation of (200) plane at lower sputtering power, while the preferred orientation was (220) plane at higher sputtering power. The N/Ti stoichiometry ratio increased from 0.67 to 0.96 with the increase of sputtering power, and the deposited TiNx thin films were off stoichiometry. Due to more formation of bonds of Ti–N in TiNx crystal, the adhesion force increased with increasing of sputtering power. The resistivity and infrared emissivity of TiNx films first deceased, and then increased with the increase of sputtering power. Defects in TiNx films prepared at 50 W led to high resistivity and infrared emissivity. The lattice distortion caused by Ti atoms was considered to play an important role in the increase of the resistivity of TiNx films at 200 W. The decrease of carrier density caused by decreased nitrogen vacancies should be the reason for the increase of the infrared emissivity of TiNx films at 80–200 W.

The Corrosion Resistance of Al Film on AZ31 Magnesium Alloys by Magnetron Sputtering

Nano Al films were prepared on AZ31 magnesium alloy samples by DC magnetron sputtering. The effects of sputtering power on the microstructure and corrosion resistance of the Al film were investigated. The results show that the surface of aluminum film is dense and polycrystalline state, and it is oriented along the Al (111) crystal plane. The grain size of Al film first increases and then decreases with the increase of sputtering power. When the sputtering power exceeds 100 W, there is no insignificant effect on the orientation of the Al crystals and the corrosion current density of the samples with Al film are reduced by two orders of magnitude. The corrosion resistance of the magnesium alloy samples with the Al film magnetron sputtered varies with the sputtering power. Compared with low sputtering power, the Al film sputtered by high power has the most excellent corrosion resistance, but too high sputtering power will lead to micro cracks on the Al film, which will adversely affect the corrosion resistance.

The Broadband Nonlinear Optical Response in Graphene/MoS2/Ag Thin Films at Near Infrared

Graphene/MoS2/Ag thin films were successfully prepared by the magnetron sputtering technique and liquid phase exfoliation. Structure, morphology, optical properties, and nonlinear optical characteristics of the graphene/MoS2/Ag and graphene/MoS2 thin films were studied by X-ray diffractometer, spectrophotometer, field-scanning electron microscope, and femtosecond (fs) Z-scan technique. The results of the fs Z-scan experiment indicate that the graphene/MoS2/Ag thin films exhibit reverse saturable absorption properties due to the free carrier absorption and two-photon absorption. More importantly, with the increase of DC magnetron sputtering power (from 5 to 15 W), the local surface plasmon resonance effect of the Ag thin films increases, which leads to the enhancement of nonlinear optical properties of the graphene/MoS2/Ag thin films. The nonlinear absorption coefficients of the graphene/MoS2/Ag thin films are increased from 1.14 × 10–10 to 1.8 × 10–10 m/W at 800 nm and from 4.79 × 10–11 to 6.79 × 10–11 m/W at 1,030 nm, and the nonlinear refraction index of the graphene/MoS2/Ag thin films is -4.37 × 10–17∼−4.18 × 10–16 m2/W under the excitation of 800 and 1,030 nm, respectively. Moreover, when the graphene/MoS2/Ag thin films were excited at 800 and 1,030 nm, respectively, the nonlinear figure of merit values of the graphene/MoS2/Ag thin films are increased from 1.23 to 2.91 and from 1.30 to 1.47, which are enough to support the application of the graphene/MoS2/Ag thin films in the field of all-optical switching applications.

Microstructure and optical properties of PbSe nanocrystalline films prepared by magnetron sputtering

PbSe nanocrystalline films were prepared using magnetron sputtering with different sputtering powers and deposition times. The obtained samples were characterized by X-ray diffractometry (XRD), field-emission scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), confocal Raman spectroscopy, UV–Vis–NIR spectroscopy, and spectrofluorophotometry. The XRD and XPS results show that the crystallization quality improves and the Pb/Se atomic ratio tends toward 1:1 with increasing sputtering power and deposition time. The morphology of PbSe particles varies from near-spherical to rod-like or cotton-like and then to triangular with increasing deposition time, consistent with the changed main growth orientation. The optical band gap of PbSe films decreases with increasing film thickness and grain size. A visible photoluminescence peak is observed at 655 nm, and its intensity strongly depends on the crystallization quality and morphology of PbSe particles, which is well consistent with the XRD and SEM results. Therefore, PbSe films with good luminescence performance can be obtained by adjusting sputtering power and deposition time.

Effects of sputtering parameters and annealing temperatures on magnetic properties of CoFeB films

In this paper, soft magnetic CoFeB films were successfully deposited onto silicon substrates using radio frequency (RF) magnetron sputtering technique and their morphology, roughness (Rq) and magnetic properties were focused. Before annealing, CoFeB films prepared with different sputtering powers (60 W, 90 W, 120 W and 150 W) exhibit amorphous structure. The out-of-plane coercivity (Hc) gradually enhances from 40.2 to 66.4 Oe as the sputtering power increases, and the saturation magnetization (Ms) reaches the maximum of 1117 emu/cm3 at 90 W sputtering power. Then, the CoFeB film samples with 90 W were annealed by 200 °C, 300 °C, 400 °C and 500 °C, respectively. Annealing treatments at 300 °C and 400 °C transfers amorphous state into crystalline state, which is demonstrated by the appearance of the observable diffraction peak of CoFe (110). The out-of-plane Hc decreases from 40.2 to 30.5 Oe at annealing temperature range of RT to 300 °C. The annealed film has a greatest Ms of 1280 emu/cm3 at 300 °C. However, the Hc gradually increases from 30.5 to 68.9 Oe annealed from 400 °C to 500 °C due to the deterioration of the thin film. Collectively, the process conditions of sputtering at 90 W and annealing at 300 °C or 400 °C are favorable for crystallization and excellent magnetic properties in CoFeB films.

Effect of sputtering power on structure and properties of ZTO films

Transparent conductive tin-doped zinc oxide (ZTO) thin films were deposited on glass substrate by using radio frequency (RF) magnetron sputtering method. The effect of sputtering power on crystalline structure, morphology, optical and electrical properties of the ZTO film was systematically studied. XRD results showed that the as-deposited ZTO thin films had a hexagonal wurtzite structure, with (002) orientation. Combining with SEM images, it was found that the grain size was increased with increasing sputtering power. The AFM images revealed that low sputtering powers of<210 W should be used to have ZTO films with small roughness (Rq). The optimized sample exhibited an average transmittance of 93.4% in the wavelength range of 400–900 nm, while the band gap had a significant red shift relative to that of the intrinsic ZnO. Carrier concentration and mobility of the ZTO films were decreased, whereas the resistivity was increased, with increasing sputtering power. The sample sputtered at 120 W had the maximized figure of merit (ФTC) of 11.87 × 10−4 Ω−1·sq, with the variation trend to nearly mirror-symmetrical with that of surface roughness of the films.