DC Reactive Magnetron Sputtering Method Research Articles

Influence of Ar:O2 Mixing Ratio on Characteristics of Tio2 Nanostructured Thin Films Deposited by DC Reactive Magnetron Sputtering Method

Abstract: In this paper, titanium dioxide nanostructured thin films TiO2 were deposited on unheated glass substrates by applying the DC reactive magnetron sputtering method. Three TiO2 films were deposited using argon sputtering gas with different oxygen ratios: 10%, 25%, and 50%. The resulting films had thicknesses of 200, 184, and 140 nm, respectively. The structural, morphological, optical, and electrical properties of deposited thin films were studied. X-ray diffraction (XRD) data showed that the samples exhibited an amorphous phase. It was found from atomic force microscopy (AFM) that the deposited thin films had a nanostructure, and the heights of their nanograins were 16, 24, and 30 nm, respectively. It was observed from the root-mean-square height RMS values that the films had low roughness. The UV-Vis-NIR spectroscopy showed that the films become more transparent with the increase in oxygen content. The direct band gap ranged between 3.68 and 3.88 eV, while the indirect band gap ranged from 3.3 to 3.66 eV. The highest intensity photoluminescence emission was obtained for the film deposited at 50% O2. In addition, the impedance spectroscopy showed that the films’ resistance did not change with changing oxygen content. Keywords: Magnetron sputtering, Titanium dioxide, X-ray diffraction, Absorption spectra, Atomic Force Microscopy, Photoluminescence, Impedance.

The Influence of Nitrogen Flow on the Stoichiometric Composition, Structure, Mechanical, and Microtribological Properties of TiN Coatings.

Utilizing reactive DC magnetron sputtering method, TiN coatings were deposited on the silicon substrates at different nitrogen flows and powers. A study of the X-ray phase composition of the coatings was carried out. The stoichiometric composition of the coatings was determined using energy dispersive x-ray spectroscopy. The structure of the surface, cross-section, and thickness of the coatings were determined using scanning electron (SEM) and atomic force microscopy (AFM). A significant change in the surface structure of TiN coatings was established with changes in deposition power and nitrogen flow. SEM images of cross-sections of all coated samples showed that the formation of coatings occurs in the form of a columnar structure with a perpendicular orientation relative to the silicon substrate. The mechanical properties (elastic modulus E and microhardness H) of TiN coatings of the first group demonstrate a maximum at a nitrogen flow of 3 sccm and are 184 ± 11 GPa and 15.7 ± 1.3 GPa, respectively. In the second group, the values of E and H increase due to a decrease in the size of the structural elements of the coating (grains and crystallites). In the third group, E and H decrease. Microtribological tests were carried out in 4 stages: at a constant load, multi-cycle for 10 and 100 cycles, and with increasing load. The coefficient of friction (CoF) and specific volumetric wear ω depend on the roughness, topology, and mechanical properties of the resulting coatings. Fracture toughness was determined using nanoscratch and depends on the mechanical properties of TiN coatings. Within each group, coatings with the best mechanical and microtribological properties were described: in the first group-TiN coating at 3 sccm (with (29.6 ± 0.1) at.% N), in the second group-TiN coating at 2 sccm (with (40.8 ± 0.2) at.% N), and in the third group-TiN coating at 1 sccm (c (37.3 ± 0.2) at.% N).

Preparing CuO, Cu2O thin films at various argon gas by using reactive dc magnetron sputtering method

Copper oxide (Cu2O, CuO) has been formed by dc reactive magnetron sputtering method of glass substrates, whereas pure target of the solid copper was sputtered with a mixture of plasma for argon gas and oxygen gas which are used form these films. Under vacuum chamber pressure on 1.2×10-5 Pa, Ar was varying from 5 to 15 sccm while other deposition parameters were fixed. X-ray photoelectron spectroscopy, XRD diffractions system, Atomic Force Microscopy (AFM), hall effect measurement system, and UV–VIS spectrophotometer were used to calculate the characteristic of the deposited thin films. Thin film at 5 sccm has investigated n-type of CuO thin film with direct band gap of 1.8eV and p-type of Cu2O at 15 sccm with direct band gap of 2.7eV. The influence of changing the Ar on the electrical and the optical properties was investigated in this study, furthermore in this study approved that the reactive dc magnetron sputtering method is suitable to prepare two type of semiconductors by change only one condition.

DC sputtered ZrO2/Zn(1−x)Sn(x)O thin-film transistors and their property evaluation

A bottom gate staggered 30 nm Zn(1−x)Sn(x)O (x = 0.14) (TZO)-based thin-film transistors (TFTs) were fabricated using DC magnetron reactive sputtering method. Highly transparent 120 nm dc sputtered ZrO2 was used as a gate dielectric. The oxygen flow rate was varied from 20 to 24% during channel layer (TZO) coating and its effect on structural, morphological, optical, chemical, and electrical parameters were systematically studied. A nano scale roughness was noticed by atomic force microscopy (AFM), and ultra-smooth nature in root mean square roughness (RMS) was observed with an increment in the oxygen flow ratio. The increase in the oxygen-related defects with increase in the oxygen flow ratio in channel layer was evident from X-ray photoelectron spectroscopy (XPS). The electrical characterization of gate dielectric was carried out for Al–ZrO2–Al structure. The high capacitance density ~ 121.9 nF/cm2 for 120 nm ZrO2 was obtained from the capacitance–voltage (C–V) measurement. The fabricated TFTs operated in n-channel depletion mode and indicated pinch-off region at lower source–drain voltages. In addition, the transfer characteristics of TFTs confirmed Ion/Ioff ratio of 105, with a field effect mobility of 23 cm2/V.s. This low temperature processed TFT unlocks the possibility of use in the next generation foldable display technology.

Formation of pure anatase TiO2 using the reactive pulsed dc magnetron sputtering method for controlling the target poisoning state

AbstractThe use of pulsed dc‐sputtering sources for reactive magnetron sputtering with oxygen offers a possibility to suppress the negative effects of target poisoning (such as arcing). This results in a wide process range for the selection of a desired operating point. The control of target poisoning plays a major role in maintaining constant coating properties and affects the stoichiometry of the reactive coating, as well as the coating rate and the economic impact of the coating process. In a hysteresis, the target poisoning during the reactive sputtering of titanium under oxygen addition proceeds nonlinearly. Without the use of a suitable target poisoning control technique, the sputtering process can abruptly change to an unstable state. As a result, variations of stoichiometry can occur during the deposition process. A proven method for maintaining a stable reactive sputtering process is the control of oxygen flow with the input variable target voltage. By determining the typical oxygen hysteresis at constant target power and constant argon flow, an operating point for the control loop is derived. The desired target voltage then serves as the input variable for the control loop of the target poisoning. The controlling technique for target poisoning is a basic requirement for the production of the photolytic active anatase phase of titanium dioxide (TiO2) using reactive magnetron sputtering. The photocatalytic equipment of surfaces with a titanium dioxide coating in the anatase phase can be realized with the reactive pulsed dc magnetron sputter ion plating process (DC‐MSIP). The pulsed DC‐MSIP process facilitates coating a variety of surfaces at temperatures below 200°C in an environmentally friendly manner.

Employment of DC Sputtering for Synthesizing Nano Cadmium Oxide for Sevoflurane Anesthetic Gas Sensor

Thin films of CdO doped with AgNPs were deposited on ITO quartz substrates using DC sputtering protocol. The films were characterized using different techniques like XRD pattern for both undoped and doped one CdO NPs with silver nanoparticles, with various doping concentrations (0.4, 1.04, and 1.20) at%. It has been noticed from X-ray pattern that the nanostructured films possessed polycrystalline reflection patterns and the Prevailing orientation plane (111) on 2θ=33.35o in addition the reflection intensity increases with increasing of the doping concentration (1chip, 2chips and 3 chips) of Silver nanoparticles that chipped to the surface cadmium plate. Microstructures characterization of synthesized samples was studied using SEM. Images of SEM demonstrated that the particle size increases directly along with the number of implanting Silver NPs with three chips (1, 2 and 3) to the essential plate of Cd metal. EDXS spectroscopy counting the elemental composition using the atomic percentage, it has been demonstrated existence of silver in doped once. More, the percentage of silver content increase with increasing the number of Ag chips increases as follows The Ag content in the doped films of the cadmium metal plate with 1 attached is (1.39 wt. % for one Ag chip, 2.02 wt. % for two Ag chips while, the concentration has been increased further for three Ag chips to 3.24 at. %. Sensitivity of the manufactured device to Sevoflurane Anesthetic Gas Sensor indicates that the resistance decreases with the increase in the number of silver chips, and this is due to an increase of the pure charge carriers of the current. Keywords: Cadmium Oxide, Sliver, Structural Properties, DC reactive magnetron sputtering method, Sevoflurane Anesthetic Gas.

Transport properties of polycrystalline TaNx thin films prepared by DC reactive magnetron sputtering method

We have investigated the electrical transport properties of polycrystalline tantalum nitride (TaNx) films. Various compositions of tantalum (nitride) thin films have been deposited on SiO2 substrates by reactive DC magnetron sputtering while changing the ratio of nitrogen partial pressure. The substrate temperature was maintained at 283 K during deposition. X-ray diffraction analyses indicated the presence of α-Ta and β-Ta phases in the Ta film deposited in pure argon atmosphere, while fcc-TaNx phases appeared in the sputtering gas mixture of argon and nitrogen. The N/Ta atomic ratio in the film increased ranging from 0.36 to 1.07 for nitrogen partial pressure from 7 to 20.7%. The superconducting transition temperatures of the TaNx thin films were measured to be greater than 3.86 K with a maximum of 5.34 K. The electrical resistivity of TaNx thin film was in the range of 177-577 μΩcm and increased with an increase in nitrogen content. The upper critical filed at zero temperature for a TaN0.87 thin film was estimated to exceed 11.3 T, while it showed the lowest Tc = 3.86 K among the measured superconducting TaNx thin films. We try to explain the behavior of the increase of the residual resistivity and the upper critical field for TaNx thin films with the nitrogen content by using the combined role of the intergrain Coulomb effect and disorder effect by grain boundaries.

Effect of Oxygen Flow Rate on Surface Morphology and Optical Properties of Reactive DC Magnetron Sputtered TiO<sub>2</sub> Thin Films

In the present work, reactive DC magnetron sputtering method is used to deposit TiO2 thin films on glass substrates. The structural, surface morphology and optical studies of TiO2 thin films were discussed by varying the oxygen flow rates from 1 to 4 sccm. X-ray diffraction patterns of TiO2 thin films show amorphous nature. The surface morphological and elemental composition of TiO2 thin films were examined by field emission scanning electron microscopy and energy dispersive X-ray spectroscopy. From the optical absorption spectra, the shifting of absorption edge towards the longer wavelength leads to the decrement of optical bandgap from 3.48 to 3.19 eV with an increase of oxygen flow rate from 1 to 4 sccm.

Surface characterization and electrochemical properties of tantalum nitride (TaN) nanostructured coatings produced by reactive DC magnetron sputtering

In this study, TaN nanostructured coatings were successfully produced on AISI 316 L stainless steel substrates using the reactive DC magnetron sputtering method. Among all of these coating processes, the only variable factor was the percentage of partial pressure of nitrogen gas (PN2) which was attended in the sputtering process. To do this, the percentage of partial pressure of nitrogen gas was chosen in different percentages of 5%, 10% and 15%. After the coatings formation, their microstructure, chemical composition and corrosion behavior were studied. The microstructure of the samples coated was studied by the scanning electron microscope (SEM), their elemental and phase composition by energy diffraction spectroscopy (EDS), X-ray diffraction (XRD) and elemental distribution was carried out by mapping (MAP) analysis. In order to study the corrosion behavior of coatings, the electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) tests were carried out in a simulated body fluid (Ringer's solution). Immersion time of specimens was determined 1, 24, 48 h and 7 days in Ringer's solution. The results of different tests showed that coatings containing 15% nitrogen consisted of hard orthorhombic and hexagonal tantalum nitride phases, had free pores and denser microstructure. This coating exhibited better corrosion behavior than the other two ones in all of the immersion times. The corrosion resistance of this coating also increased by rising immersion time from 1 h to 7 days. In fact, the coating containing 15% of nitrogen being immersed for 7 days with a resistance of 118.68 (MΩ.cm2), had the highest corrosion resistance.

The Effect of Annealing Temperature on Structure of TiCrN Thin Film Deposited by DC Magnetron Sputtering Method

The DC reactive magnetron sputtering method was employed to deposit Titanium Chromium Nitride (TiCrN) thin film on silicon (100) substrates. The coatings were annealed at different temperature from 700°C to 1000°C with increase step of 100 °C in air for 2 h. The crystal structure, surface morphologies, microstructure and chemical compositions were investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray spectroscopy (EDX). The x-ray patterns confirmed the TiO2 rutile structure with strong preferred orientation of (101) plane was appeared from 700°C. The crystallinity of film increased with the annealing temperatures. The lattice constant (a and c) were in the range of 4.565 – 4.607 Å and 2.946 – 2.956 Å. The void between grain boundaries was confirmed by FE-SEM micrograph. The cross-sectional analysis revealed that the porous structure with enhancement of thickness from 1.64 - 1.95 μm were obtained as increase annealing temperatures. The EDX results indicated that the O content increase from 0 – 60.67 At% whereas the Ti, Cr, and N contents were decreased from 43.26 - 22.40 At%, 20.65 – 2.57 At% and 51.19 – 14.36 At% through the annealing temperatures.

Enhanced Electrochromic Properties by Improvement of Crystallinity for Sputtered WO3 Film

Tungsten oxide (WO3) is widely used as a functional material for “smart windows” due to its excellent electrochromic properties, however it is difficult to overcome the conflict between its optical modulation and cyclic stability. In this work, WO3 thin films with different crystal structures were prepared by DC reactive magnetron sputtering method. The effects of substrate temperature on the structure, composition, and electrochromic properties of WO3 films were investigated. The results show that the crystallinity of the WO3 film increases with increasing deposition temperature, indicating that temperature plays an important role in controlling the structure of the WO3 film. For WO3 thin films formed at a substrate temperature of 573 K, the film is in an amorphous state to a crystalline transition state. From X-ray diffraction (XRD) analysis, the thin film showed a weak WO3 crystallization peak, which was in the composite structure of amorphous and nanocrystalline. Which has the best electrochromic properties, with modulation amplitude of 73.1% and bleached state with a coloration efficiency of 42.9 cm2/C at a wavelength of 550 nm. Even after 1500 cycles, the optical modulation still contains 65.4%, delivering the best cyclic stability.

Effect of oxygen flow rate on physical properties of Al-doped ZnO transparent conducting films prepared by reactive dc magnetron sputtering using metallic Zn:Al target

In this work, Al-doped ZnO transparent conducting thin films were prepared by a reactive dc magnetron sputtering method on slide glass substrate using single metallic Zn:Al (2 wt.% Al) target with the oxygen flow rate 1, 3, 5, 7 and 9 sccm, respectively. From XRD patterns, the films prepared at R(O2) of 1 sccm showed amorphous characteristics. In contrast, the films prepared at R(O2) of 3, 5, 7 and 9 sccm showed the preferred orientation (002) plane of hexagonal structure. Surface morphology and diameter of nanocolumns of the films were observed by AFM and FESEM. From transmittance spectra, energy gap value was found to vary between 3.24 and 3.32 eV. Electrical resistivity and Hall effect measurements were performed on the films with van der Pauw configuration. The temperature-dependent conductivity was performed in the range 20-300 K. Three types of conduction mechanisms were expected. Thermally activated band conduction at the high temperature range (250-300 K), Mott variable-range hopping (Mott-VRH) at the low temperature range (100-210 K) and Efros-Shklovskii variable-range hopping (ES-VRH) at the very low temperature range (<100 K) can be found in the films prepared with different oxygen flow rate conditions. Except for the oxygen flow rate at 5 sccm, the behavior of weakly localized electrons was observed. Then, the sets of parameters explaining the properties of localized electrons in each conduction regime were determined. The results indicated that the reactive dc magnetron sputtering using a single metallic Zn:Al (2 wt.% Al) target is suitable for TCO films since it can be easily obtained at low temperatures with good physical properties.

Performance improvement of TiO2/CuO by increasing oxygen flow rates and substrate temperature using DC reactive magnetron sputtering method

In the present study, TiO2/CuO solar cells have been successfully fabricated for the first time using DC reactive magnetron sputtering for application in PV devices. To improve the performance of TiO2 and CuO solar cells, we increased the oxygen flow rates and substrate temperature during the deposition of TiO2 and CuO thin films compared with our previous work. The structural features by X-ray diffraction and energy-dispersive X-ray spectroscopy spectrum(s) with the atomic percent were analyzed. Next, scanning electron microscopy images with cross-sections were compared. Finally, current–voltage characteristics (I-V) capacitance–voltage (C-V) were determined. The PV parameters, open circuit voltage, short circuit current, fill factor, and efficiency, were then analyzed and compared. We observed a maximum efficiency of 0.24 % and an open circuit voltage of 0.14 V. To the best of our knowledge, we attained the fourth highest efficiency reported to date. The C-V and I-V characteristics were compared with theoretical calculations obtained with the solar cell capacitance simulator, SCAPS, program.

Lifetime and Performance Improvement of HSS Drill Bit by Titania (TiO2) Nano-Coatings and Cryogenic Treatment

The small and medium scale industry in drilling and cutting sector widely use cutting tools made by High Speed Steel (HSS). The improvement of lifetime of HSS drill bits helps these establishments to achieve product economy. The improvement in the performance and service lifetime of high-speed steel (HSS) twisted drill bits are studied by depositing Titanium dioxide (TiO2) nano-coatings using reactive dc magnetron sputtering Method. Pure titanium (99.99%) metal is used as target material for making nano-coatings in oxygen atmosphere. X-ray diffraction studies indicated change of phase of annealed samples compared to as-deposited coatings. X-ray reflection (XRR) measurements estimated nanocoating thickness on the HSS drill bit around 100nm. The lifetime of TiO2 nano-coated, and cryogenically treated nano-coated tools significantly improved compared to uncoated (bare) HSS drill bit. The tool life has been enhanced by about 16% when TiO2 nano-coatings were made on HSS drill bits. Further lifetime enhancement of 10% was observed when the nanocoated drill bit is given cryogenic treatment in liquid nitrogen. SEM images and EDS profiles are reported. The minimum surface roughness measured as 7.296x10-6m for TiO2 coated and cryo-treated HSS drill tool.

High quality NbTiN films fabrication and rapid thermal annealing investigation**Project supported by the Chinese Academy of Sciences Strategic Priority Research Program B (Grant No. XDB07010300) and the National Natural Science Foundation of China (Grant No. 11674376).

NbTiN thin films are good candidates for applications including single-photon detector, kinetic inductance detector, hot electron bolometer, and superconducting quantum computing circuits because of their favorable characteristics, such as good superconducting properties and easy fabrication. In this work, we systematically investigated the growth of high-quality NbTiN films with different thicknesses on Si substrates by reactive DC-magnetron sputtering method. After optimizing the growth conditions, such as the gas pressure, Ar/N2 mixture ratio, and sputtering power, we obtained films with excellent superconducting properties. A high superconducting transition temperature of 15.5 K with narrow transition width of 0.03 K was obtained in a film of 300 nm thickness with surface roughness of less than 0.2 nm. In an ultra-thin film of 5 nm thick, we still obtained a transition temperature of 7.6 K. In addition, rapid thermal annealing (RTA) in atmosphere of nitrogen or nitrogen and hydrogen mixture was studied to improve the film quality. The results showed that Tc and crystal size of the NbTiN films were remarkably increased by RTA. For ultrathin films, the annealing in N2/H2 mixture had better effect than that in pure N2. The Tc of 10 nm films improved from 9.6 K to 10.3 K after RTA in N2/H2 mixture at 450 °C.

Microstructure and tribocorrosion performance of nanocrystalline TiN graded coating on biomedical titanium alloy

Abstract A nanocrystalline TiN graded coating was prepared on Ti6Al4V alloy by DC reactive magnetron sputtering method. The microstructure and mechanic properties of the coating were investigated. The electrochemical corrosion and tribocorrosion of the coated specimens in physiological environment were compared with those of Ti6Al4V substrate. The results show that the gradient distribution of nanocrystalline TiN is favorable for releasing the inner stress in the coating, which increases adhesion strength to 90 N. The compact structure and refined-grains of the coating result in the surface nanohardness of 28.5 GPa. The corrosion protection efficiency of the nanocrystalline TiN coating reaches 96.6%. The tribocorrosion resistance of the coating increases by 100 times in comparison with that of Ti6Al4V substrate. The high chemical stability and H3/E2 ratio (where H is hardness, and E is elastic modulus) of the nanocrystalline TiN coating are responsible for good corrosion and wear resistances.

Fabrication of p-type TiO2 and transparent p-TiO2/n-ITO p-n junctions

This study reports a transparent p-type TiO2 thin film by DC reactive magnetron sputtering method with 10% O2 partial pressure. The p-type conduction of TiO2 thin film was also confirmed by Seebeck effect. The lowest resistivity (1.458×10-2 Ω·cm) of the studied TiO2 thin film occurs at the annealing temperature of 500 °C in the under N2 atmosphere ambient. We believe that the p-type conduction mechanism of the as-deposited TiO2 thin films with 10% O2 partial pressure could be caused by the defect reaction mechanism, i.e., the Ti2+-Ti4+ substitution reaction. A transparent p-n junction of p-TiO2/n-ITO was fabricated by photolithography and lift-off processes. The I-V curve of p-TiO2/n-ITO junction shows that p-TiO2/n-ITO p-n junction clearly exhibits a good diode characteristic with a turn-on voltage of about 3.19 V under forward-biased voltage, which corresponds to the band gap of the TiO2. It further proves that the current studied TiO2 thin film prepared with 10% O2 partial pressure is the p-type conduction.

Effect of Oxygen Flow Rate on Structural, Electrical and Optical Properties of Zinc Aluminum Oxide Thin Films Deposited by DC Magnetron Sputtering

Zinc Aluminum Oxide thin films were deposited on glass substrates by reactive DC magnetron sputtering method by varying oxygen flow rates from 1 to 4 sccm. Glancing angle X-ray diffraction patterns ofzinc aluminum oxide thin films exhibits (0 0 2) peak with c-plane preferentially oriented parallel to the substrate. The surface morphology and elemental analysis of the films was observed by field emission scanning electron microscopy attached with energy dispersive X-ray analysis spectroscopy. An average optical transmittance of 83–90% is obtained for the films deposited at various oxygen flow rates. The optical band gap of the films increases from 3.41 to 3.53 eV with the increase of oxygen flow rate due to Burstein–Moss effect. The optical dispersion parameters such as dispersion energy (Ed), oscillator energy (Eo) and static refractive index (no) were determined using the Wemple-DiDomenico (W-D) single oscillator model. The nonlinear optical parameters such as optical susceptibility (χ(1)), third order nonlinear optical susceptibility (χ(3)) and nonlinear refractive index (n2) were also determined.

Влияние промежуточной ионной очистки титановой мишени на структуру биорезорбируемых полимерных скаффолдов из полимолочной кислоты при формировании покрытий методом DC реактивного магнетронного распыления

Влияние промежуточной ионной очистки титановой мишени на структуру биорезорбируемых полимерных скаффолдов из полимолочной кислоты при формировании покрытий методом DC реактивного магнетронного распыления

Effect of oxygen flow rate on structural, electrical and optical properties of zinc aluminum oxide thin films deposited by DC magnetron sputtering -=SUP=-*-=/SUP=-

AbstractZinc Aluminum Oxide thin films were deposited on glass substrates by reactive DC magnetron sputtering method by varying oxygen flow rates from 1 to 4 sccm. Glancing angle X-ray diffraction patterns ofzinc aluminum oxide thin films exhibits (0 0 2) peak with c-plane preferentially oriented parallel to the substrate. The surface morphology and elemental analysis of the films was observed by field emission scanning electron microscopy attached with energy dispersive X-ray analysis spectroscopy. An average optical transmittance of 83–90% is obtained for the films deposited at various oxygen flow rates. The optical band gap of the films increases from 3.41 to 3.53 eV with the increase of oxygen flow rate due to Burstein–Moss effect. The optical dispersion parameters such as dispersion energy ( E _ d ), oscillator energy ( E _ o ) and static refractive index ( n _ o ) were determined using the Wemple-DiDomenico (W-D) single oscillator model. The nonlinear optical parameters such as optical susceptibility (χ^(1)), third order nonlinear optical susceptibility (χ^(3)) and nonlinear refractive index ( n _2) were also determined.