DC Magnetron Co-sputtering Technique Research Articles

Dense and hard TiWC protective coatings grown with tungsten ion irradiation using WC-HiPIMS/TiC-DCMS co-sputtering technique without external heating

Titanium tungsten carbide (TiWC) coatings are deposited by a combined high-power impulse and dc magnetron co-sputtering (HiPIMS/DCMS) technique. No external heating is applied during deposition phase, instead, the thermally driven adatom mobility is substituted by heavy ion irradiation. DCMS sources equipped with titanium carbide targets provide constant neutral fluxes to establish the predominant coating structures, whereas tungsten carbide target in HiPIMS mode serves as the source of heavy metal-ions. Substrate bias of −60 V is synchronized to W+ ion-rich time domains of HiPIMS pulses to minimize the contribution from working gas ions. The influence of W+ ion flux intensity, controlled by varying peak target current density (JT), on film properties is investigated. X-ray photoelectron spectroscopy reveals the presence of over stoichiometric carbon forming an amorphous phase, the amount of which can be fine-tuned by varying JT. Changes in film composition as a function of JT are explained based on the in-situ ion mass spectroscopy analyses. Dense TiWC coatings by hybrid process exhibit hardness higher than 30 GPa, which are comparable to TiWC films deposited by DCMS with dc substrate bias and external heating. The relative energy consumption in the hybrid process is reduced by 77 % as compared to high-temperature DCMS processing.

Effects of substrate rotation during AlSi-HiPIMS/Ti-DCMS co-sputtering growth of TiAlSiN coatings on phase content, microstructure, and mechanical properties

A combined high-power impulse and dc magnetron co-sputtering (HiPIMS/DCMS) technique is used to deposit Ti0.6Al0.32Si0.08N films with 1-fold substrate table rotation. Layers are grown at two different substrate-target separations, two different rotational speeds, and with different values of substrate bias. The aim is to study the role of (1) overlap between ion and neutral fluxes generated from HiPIMS and DCMS sources, respectively, and (2) the subplantation range of low-mass ions. Results from X-ray diffractometry highlight the necessity of flux intermixing in the formation of the metastable B1-structured TiAlSiN solid solutions. All films grown at short target-to-substrate distance contain the hexagonal AlN phase, as there is essentially no overlap between HiPIMS and DCMS fluxes, thus the Al+ and Si+ subplantation is very limited. Under conditions of high flux intermixing corresponding to larger target-to-substrate distance, no w-AlN forms irrespective of rotational speed (1 or 3 rpm) and bias amplitude (120 or 480 V), indicating that the role of Al+/Si+ and Ti flux overlap is crucial for the phase formation during film growth by HiPIMS/DCMS with substrate rotation. This conclusion is further supported by the fact that the reduction of the bilayer thickness with increasing the target-to-substrate distance (hence increasing flux overlap) is larger for films grown with higher amplitude of the substrate bias, indicative of more efficient Al+/Si+ subplantation into the c-TiN phase. Single-phase films with the hardness close to that of layers grown with stationary substrate table can be achieved, however, at the expense of higher compressive stress.

The Effect of Working Gases Mixing Ratios on the Synthesis and Characteristics of TiO2/SiO2 Nanocomposite via Closed-Field unbalanced DC Magnetron Co-Sputtering Technique

The objective of this research is to study the influence of deposition parameters such as gases mixing ratio O2/Ar on the structural and optical properties of the TiO2/SiO2 nanocomposite films synthesized using closed field unbalanced dc magnetron co-sputtering technique. The nanocomposite thin films were characterized using x-ray diffraction (XRD) to determine the phase structure, and Fourier transform infrared (FTIR) spectroscopy to investigate Si-O-Si, Ti-O and Si–O–Ti. functional groups. The UV-VIS. absorption spectra of the synthesized films reveal that the indirect energy band gap was found to be 2.75 eV. The mixing ratio of Oxygen and Argon (O2/Ar) gases has a pronounced controlling effect on the structural and optical properties of such nanocomposite.

Effect of Ar/N2 flow ratio on the microstructure and mechanical properties of Ti-Cr-N coatings deposited by DC magnetron sputtering on AISI D2 tool steels

Ti-Cr-N coatings were deposited on Si (100) and AISI D2 tool steel substrates by reactive DC magnetron co-sputtering technique from titanium and chromium target in mixed Ar/N2 atmosphere. The Ar/N2 ratio effects on the chemical composition, structure, morphology, intrinsic stress and mechanical properties of the Ti-Cr-N coatings were investigated. The growing process of Ti-Cr-N coatings can be divided into three stages: Stage I, in poisoning mode (low flow ratio 1 < Ar/N2 ≤ 1.4), Stage II, in transition mode (intermediate flow ratio 1.4 ≤ Ar/N2 ≤ 3) and Stage III in metallic mode (Ar/N2 > 3). For all samples, XRD analysis shown the formation of mixed nitrides phases. In stage I, Ti2N, TiN0.3, and hexagonal-Cr2N phases were observed. In Stage II, TiN0.3, Cr2N, and cubic-TiN phases were formed, while only TiN and Cr2N are observed in stage III. The coatings deposited with Ar/N₂ ratio of 3 shows the largest hardness of 24 GPa which is attribute to the dense structure and smoother surface morphology. The properties of the films are discussed in terms of evolution growth stages resulting by the variation of Ar/N2 flow ratios.

Development of reflective co-sputtered nanostructured metallic films

ABSTRACT DC magnetron co-sputtering technique is utilised to develop reflective Ag- and Al-based metal films co-sputtered with Ni deposited on quartz glass substrates. The sputtered films are characterised by field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM) and X-ray diffraction (XRD) techniques to investigate microstructure, topology and phase analysis, respectively. Further, average thermo-optical properties such as solar reflectance, absorptance and IR emittance and electrical property such as sheet resistance of the deposited films are evaluated. The reflectance property as a function of wavelength is also investigated. Sputtered Ag and Al films show high (>93%) reflectance, however, co-sputtered Al + Ni and Ag + Ni offer comparatively lesser value, e.g. 45% and 73%, respectively. The significant lower reflectance of Al + Ni is possibly due to the presence of higher amount of Ni in the film and the formation of intermetallic compounds.

The observation of tin islands in Nb3Sn thin films deposited by magnetron sputtering

Superconducting Nb3Sn thin films have been produced on copper substrate by dc magnetron co-sputtering technique successfully. XRD and magnetic moment measurement demonstrate the exist of Nb3Sn crystal. By changing the ratio between niobium target sputtering current to tin target, the tin concentration in different films is varied. However, the experiment results indicate critical temperature TC of different Nb3Sn thin film are nearly invariable while the composition of Nb-Sn of those are changed. Highest TC of those films annealing at 650°C are around 12K, while 750°C annealing increase it to 15K. The SEM and element analysis results manifest inhomogenous distribution of tin atoms, where some tin islands appear over the film. The exist of tin-rich areas like tin islands is responsible for such particular performance of Nb3Sn films.

Synthesis and Characterization of CdSnTe Nanostructures by Magnetron Co-Sputtering of Thermally Alloyed Targets for Photonics Applications

In this work, nanostructured cadmium tin telluride (CdSnTe) thin films were deposited on glass substrates by dc magnetron co-sputtering technique. The sputtered target was prepared by the thermal alloying of Cd, Sn and Se samples at 500 °C. The structural characterizations showed that the prepared targets were polycrystalline while the deposited CdSnTe films exhibited amorphous structure due to the growth of nanostructures on the substrates, which was also confirmed by the scanning electron microscopy. These films showed high absorption in the ultraviolet region, which is decreasing with wavelength with an absorption edge at about 550 nm. These films are approximately transparent in the near-infrared region (>800nm). The energy band gap of these films was determined to be direct allowed of 1.9655 eV. The photoluminescence measurements on the deposited films showed some enhancement in the intensity with a blue-shift in peak wavelength when compared to the CdTe thin films prepared by the same technique.

Sub-ppm level detection of trimethylamine using V2O3-Cu2O mixed oxide thin films

The present work deals in developing mixed compounds of vanadium sesquioxide (V2O3) and cuprous oxide (Cu2O) thin films using direct current (dc) magnetron co-sputtering technique for the detection of trimethylamine (TMA) vapour at ambient temperature (∼30 °C). The X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HR-TEM) characterizations confirmed the amorphous nature of V2O3-Cu2O thin film. The chemical stoichiometry of the mixed oxide film was determined as V+3 and Cu+1 oxidation states using X-ray photoelectron spectroscopy (XPS) analysis. The nanograin like morphology with an average particle size and thickness of about ∼15 and ∼85 nm was observed from field-emission scanning electron microscopy (FE-SEM). The TMA sensing studies proved that the sensor can detect a minimum of 3 ppm concentration with a sensor response (S = Ra/Rg) of ∼1.08. The developed sensor exhibited better sensitivity towards amine groups than alcohol, aldehyde, and ketone groups. Hence, it is believed that the developed Cu2O–V2O3 (VCO) mixed oxide can be a better amine sensor that can be utilized for the determination of fish quality.

Network mixed metal oxide (V4+ and Ti4+) nanostructures as potential material for the detection of trimethylamine

Room temperature trimethylamine sensing studies of mixed oxide VO2–TiO2 thin films deposited using the reactive dc magnetron co-sputtering technique.

Growth and crystallization of Cobalt-doped TiO2 alloys: Effect of substrate and annealing temperature

This work presents a study of the structural and optical properties of cobalt-doped titanium dioxide thin films prepared via the DC Magnetron Co-Sputtering technique using TiO2 and Co targets with 99.99% purity; these thin films were deposited on three different substrates: Soda-lime glass, titanium foil and silicon wafer. The resulting films deposited on glass were then submitted to annealing processes at temperatures ranging from 500 °C to 600 °C. X-ray diffraction measurements revealed limited crystallization of the as-deposited samples, whilst the annealed samples showed several crystalline phases, including cobalt oxide (Co3O4) and a ternary phase (CoTi2O5); SEM studies helped to corroborate that the inclusion of TiO2 into the thin film decreases its crystallinity, obtaining nanostructures smaller in size as compared with samples containing cobalt. UV-vis-NIR measurements revealed an increase in transparence of the thin films after annealing at 600 °C, evidencing extrinsic absorption phenomena, consistent with the formation of binary phases inside the semiconductor matrix. From XPS measurements, the oxidation states for Co and Ti were obtained.

Effect of crystallographic orientation on structural and mechanical behaviors of Ni–Ti thin films irradiated by Ag7+ ions

In the present study, thin films of Ni–Ti shape memory alloy have been grown on Si substrate by dc magnetron co-sputtering technique using separate sputter targets Ni and Ti. The prepared thin films have been irradiated by 100 MeV Ag7+ ions at three different fluences, which are 1 × 1012, 5 × 1012, and 1 × 1013 ions/cm2. The elemental composition and depth profile of pristine film have been investigated by Rutherford backscattering spectrometry. The changes in crystal orientation, surface morphology, and mechanical properties of Ni–Ti thin films before and after irradiation have been studied by X-ray diffraction, atomic force microscopy, field-emission scanning electron microscopy, and nanoindentation techniques, respectively. X-ray diffraction measurement has revealed the existence of both austenite and martensite phases in pristine film and the formation of precipitate on the surface of the film after irradiation at an optimized fluence of 1 × 1013 ions/cm2. Nanoindentation measurement has revealed improvement in mechanical properties of Ni–Ti thin films after ion irradiation via increasing hardness and Young modulus due to the formation of precipitate and ductile phase. The improvement in mechanical behavior could be explained in terms of precipitation hardening and structural change of Ni–Ti thin film after irradiation by Swift heavy ion irradiation.

Fabrication of porous silicon filled Pd/SiC nanocauliflower thin films for high performance H2 gas sensor

In this work, we have fabricated the Pd decorated silicon carbide (SiC) nanocauliflowers (NCs) thin films on electrochemically etched porous silicon (PS) substrate by DC magnetron co-sputtering technique. The gas sensing performance of Pd/SiC NCs to hydrogen gas under low (5–500 ppm) detection limit at high operating temperature regime (40–500 °C) were studied in detail without additional processing. The nanocauliflowers sensor demonstrates the high sensing response (Ra/Rg ̴ 14.48), fast response/recovery time (10s/18s) with excellent stability (24 cycles) towards 100 ppm H2 at high temperature of 380 °C. The underlying sensing mechanism behind the notable performance of the proposed sensing action towards H2 was also discussed in detail. Therefore, the investigated Pd/SiC NCs can be used as highly sensitive and selective hydrogen gas sensor at high working temperatures in harsh environment.

Ag implantation-induced modification of Ni–Ti shape memory alloy thin films

ABSTRACTNanocrystalline thin films of Ni–Ti shape memory alloy are deposited on an Si substrate by the DC-magnetron co-sputtering technique and 120 keV Ag ions are implanted at different fluences. The thickness and composition of the pristine films are determined by Rutherford Backscattering Spectrometry (RBS). X-Ray diffraction (XRD), atomic force microscopy (AFM) and four-point probe resistivity methods have been used to study the structural, morphological and electrical transport properties. XRD analysis has revealed the existence of martensitic and austenite phases in the pristine film and also evidenced the structural changes in Ag-implanted Ni–Ti films at different fluences. AFM studies have revealed that surface roughness and grain size of Ni–Ti films have decreased with an increase in ion fluence. The modifications in the mechanical behaviour of implanted Ni–Ti films w.r.t pristine film is determined by using a Nano-indentation tester at room temperature. Higher hardness and the ratio of higher hardness (H) to elastic modulus (Er) are observed for the film implanted at an optimized fluence of 9 × 1015 ions/cm2. This improvement in mechanical behaviour could be understood in terms of grain refinement and dislocation induced by the Ag ion implantation in the Ni–Ti thin films.

Structural Characterization of Reactive DC Magnetron Co-Sputtered Nanocrystalline CrAlN Thin Film

Nanocrystalline CrAlN thin films were deposited on silicon substrates by reactive DC magnetron co-sputtering technique. The effect of deposition time on crystal structure, chemical composition, thickness, microstructure and hardness of the thin films were characterized by XRD, EDS, AFM and FE-SEM and Nanoindentation, respectively. The as-deposited films were formed as a (Cr,Al)N solid solution with (111), (200) and (220) plane. The lattice constants were in range of 3.9916 - 4.0455 Å. The as-deposited films exhibited a nanostructure with a crystallite size in range of 15-35 nm. The thickness and roughness increased from 197 nm to 998 nm and 1.6 nm to 8.1 nm, respectively, with increasing the deposition time. The chemical composition of the films varied with the deposition time. The cross section analysis by FE-SEM showed columnar structure and dense morphology. The film hardness decreased from 39 GPa to 25 GPa with increasing the deposition time and crystallite size.

Effect of Deposition Time on Structure of TiAlN Thin Films Deposited by Reactive DC Magnetron Co-Sputtering

Titanium aluminum nitride (TiAlN) thin films were deposited by reactive DC magnetron co-sputtering technique on Si substrate. The effect of deposition time on the structure of the TiAlN films was investigated. The crystal structure, surface morphology, thickness and elemental composition were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray spectroscopy (EDS) technique, respectively. The results showed that, all the as-deposited films were formed as a (Ti,Al)N solid solution. The as-deposited thin films exhibited a nanostructure with a crystallite size of less than 30 nm. The film thickness increase from 115 nm to 329 nm, while the lattice parameter decrease from 4.206 Å to 4.196 Å, with increasing of the deposition time. Cross section analysis by FE-SEM showed compact columnar and dense morphology as a result of increasing the deposition time. The elemental composition of the as-deposited films varied with the deposition time.

Effect of Al Sputtering Current on Structure of CrAlN Thin Films Prepared by Reactive DC Magnetron Co-Sputtering

Chromium aluminium nitride (CrAlN) thin films were deposited on Si by reactive DC magnetron co-sputtering technique. The effect of Al sputtering current (IAl) on the crystal structure, elemental composition, thickness, microstructure and hardness were determined by XRD, EDS, AFM and FE-SEM and Nanoindentation, respectively. The results showed that, the as-deposited films were formed as a (Cr,Al)N solid solution with low Al sputtering current, whereas the amorphous structure can be found at high Al sputtering current. The film thickness and roughness was in range of 347 - 1047 nm and 1.45 - 3.37 nm, respectively. The elemental composition of the films varied with the Al sputtering current. The FE-SEM results indicated that the simultaneous evolution in grain refinement with cross-section microstructure through the Al sputtering current. The film hardness increased from 36 GPa to 46 GPa with increasing of Al contents.

Low-temperature growth of dense and hard Ti0.41Al0.51Ta0.08N films via hybrid HIPIMS/DC magnetron co-sputtering with synchronized metal-ion irradiation

Hard Ti1−xAlxN thin films are of importance for metal-cutting applications. The hardness, thermal stability, and oxidation resistance of these coatings can be further enhanced by alloying with TaN. We use a hybrid high-power pulsed and dc magnetron co-sputtering (HIPIMS/DCMS) technique to grow dense and hard Ti0.41Al0.51Ta0.08N alloys without external heating (Ts &amp;lt; 150 °C). Separate Ti and Al targets operating in the DCMS mode maintain a deposition rate of ∼50 nm/min, while irradiation of the growing film by heavy Ta+/Ta2+ ions from the HIPIMS-powered Ta target, using dc bias synchronized to the metal-ion-rich part of each HIPIMS pulse, provides effective near-surface atomic mixing resulting in densification. The substrate is maintained at floating potential between the short bias pulses to minimize Ar+ bombardment, which typically leads to high compressive stress. Transmission and scanning electron microscopy analyses reveal dramatic differences in the microstructure of the co-sputtered HIPIMS/DCMS films (Ta-HIPIMS) compared to films with the same composition grown at floating potential with all targets in the DCMS mode (Ta-DCMS). The Ta-DCMS alloy films are only ∼70% dense due to both inter- and intra-columnar porosity. In contrast, the Ta-HIPIMS layers exhibit no inter-columnar porosity and are essentially fully dense. The mechanical properties of Ta-HIPIMS films are significantly improved with hardness and elastic modulus values of 28.0 and 328 GPa compared to 15.3 and 289 GPa for reference Ta-DCMS films.

Silicon Carbide Nanocauliflowers for Symmetric Supercapacitor Devices

The efficiency of silicon carbide (SiC) nanocauliflowers (NCs) as electrode material for supercapacitor application has been investigated in detail in the present work. The SiC NCs were deposited on Ag coated porous alumina (AAO) substrates via a DC magnetron cosputtering technique at room temperature. The Ag coated porous AAO substrate acts as an excellent current collector and also enhances the high specific capacitance of SiC NCs up to ∼300 F/g at 5 mV/s. The fabricated symmetric supercapacitor device delivered a high specific capacitance (188 F/g at 5 mV/s), good cycling ability (97.05% capacitance retention after 30,000 cycles), high energy density (31.43 Wh/kg), and also a high power density (∼18.8 kW/kg at 17.76 Wh/kg) in a voltage range of 1.8 V. These observed excellent electrochemical performances of the present SiC NCs based device suggest it has tremendous potential as supercapacitor electrodes in energy storage applications.

Structural, Morphological and Electrical Properties of In-Doped Zinc Oxide Nanostructure Thin Films Grown on p-Type Gallium Nitride by Simultaneous Radio-Frequency Direct-Current Magnetron Co-Sputtering**Supported by the RU Top-Down under Grant No 1001/CSS/870019.

Zinc oxide (ZnO) is one of the most promising and frequently used semiconductor materials. In-doped nanostructure ZnO thin films are grown on p-type gallium nitride substrates by employing the simultaneous rf and dc magnetron co-sputtering technique. The effect of In-doping on structural, morphological and electrical properties is studied. The different dopant concentrations are accomplished by varying the direct current power of the In target while keeping the fixed radio frequency power of the ZnO target through the co-sputtering deposition technique by using argon as the sputtering gas at ambient temperature. The structural analysis confirms that all the grown thin films preferentially orientate along the c-axis with the wurtzite hexagonal crystal structure without having any kind of In oxide phases. The presenting Zn, O and In elements' chemical compositions are identified with EDX mapping analysis of the deposited thin films and the calculated M ratio has been found to decrease with the increasing In power. The surface topographies of the grown thin films are examined with the atomic force microscope technique. The obtained results reveal that the grown film roughness increases with the In power. The Hall measurements ascertain that all the grown films have n-type conductivity and also the other electrical parameters such as resistivity, mobility and carrier concentration are analyzed.

Ion Beam Analysis, structure and corrosion studies of nc-TiN/a-Si3N4 nanocomposite coatings deposited by sputtering on AISI 316L

In this work, nanocomposite coatings of nc-TiN/a-Si3N4, were deposited on AISI 316L stainless steel substrate by a DC and RF reactive magnetron co-sputtering technique using an Ar–N2 plasma. The structure of the coatings was characterized by means of XRD (X-ray Diffraction). The substrate and coating corrosion resistance were evaluated by potentiodynamic polarization using a Ringer solution as electrolyte. Corrosion tests were conducted with the purpose to evaluate the potential of this coating to be used on biomedical alloys. IBA (Ion Beam Analysis) techniques were applied to measure the elemental composition profiles of the films and, XPS (X-ray Photoelectron Spectroscopy) were used as a complementary technique to obtain information about the compounds present in the films.The nanocomposite coatings of nc-TiN/a-Si3N4 show crystalline (TiN) and amorphous (Si3N4) phases which confer a better protection against the corrosion effects compared with that of the AISI 316L.