Magnetron Sputter Deposition System Research Articles

Hydrogen-free DLC films fabricated using superimposed HiPIMS-DCMS deposition system: Bias voltage effects

Diamond-like carbon (DLC) films were grown using a superimposed high-power pulse magnetron sputtering and direct current magnetron sputtering (HiPIMS-DCMS) deposition system at various bias voltages from 0 to −350 V. The microstructure, mechanical and tribological properties of the films were studied in relation to bias voltage. The results suggested that the deposition rate of DLC films decreased gradually with the enhancement of bias voltages. The surface roughness of DLC films decreased from 2.81 nm to 0.54 nm. The values of ID/IG of DLC films decreased first and increased later with the enhancement of bias voltages, and the value of ID/IG was the minimum at −150 V. Therefore, the highest sp3 CC fraction of DLC film was obtained when deposited at −150 V. Moreover, the hardness and internal stress of DLC films also show the law of increasing first and decreasing later. DLC film obtained the maximum hardness and highest internal stress of 32.0 GPa and − 2.08 GPa at −150 V. Finally, the friction test suggested that the films had excellent tribological performance. In particular, the film deposited at −150 V had excellent tribological properties, including low friction coefficient (0.095) and low wear rate (1.36 × 10−7 mm3/N·m).

RF/DC Magnetron Sputtering Deposition of Thin Layers for Solar Cell Fabrication

Thin film Cu(In,Ga)Se2 (CIGS)-based solar cells with relatively high efficiency and low material usage might become a promising alternative for crystalline silicon technology. The most challenging task nowadays is to decrease the PV module fabrication costs by application of easily scalable industrial process. One of the possible solutions is the usage of magnetron sputtering system for deposition of all structures applied in CIGS-based photovoltaic device. The main object of these studies was fabrication and characterization of thin films deposited by sputtering technique. Structural and electrical properties of the sputtered films were analyzed using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray Powder Diffraction (XRD), and four-point probe resistivity measurements. The presented findings revealed technological parameters for which sheet resistance of molybdenum (Mo) back contact decreased up to 0.3 Ω/□ and to even 0.08 Ω/□ in case of aluminum layer. EDS analysis provided evidence for the appropriate stoichiometry of CIGS absorber (with CGI and GGI equal to 0.96 and 0.2, respectively). XRD characterization confirmed high-quality chalcopyrite polycrystalline structure of Cu(In,Ga)Se2 film fabricated at relatively low substrate temperature of 400 °C. Characteristic XRD peaks of hexagonal-oriented structures of sputtered CdS and i-ZnO layers were noticed.

(Invited) Fabrication and Characterization of B- or P- Doped Silicon Nanoparticles Embedded in SiOxNy Transparent Matrix

Silicon nanocrystals (Si-Ncs)-based devices are some of the most studied nanomaterials and could be of great interest in many fields such as electronics1, optical sensing2, photovoltaics3 and biomedicine4. First of all, it is important to control their size, shape and aggregation which are parameters related to their potential applications. In our case, these Si-Ncs are embedded in an insulating dielectric matrix of SiOxNy, resulting in a composite material with a tunable effective bandgap. Doping Si-Ncs can enlarge their applicability by modifying their electrical properties5, the effective bandgap5, the light absorption range and the nanoparticles photoluminescence.In this study, we used a magnetron sputtering deposition system to deposit silicon rich silicon oxynitride (SiOxNy) thin films. Then, n- and p-type dopants such as boron, arsenic and phosphorus were introduced in the thin films using ion implantation which was carried out at different doses and accelerating energies5. Thanks to a thermal treatment at high temperature, silicon atoms diffuse and nucleate to form silicon nanostructures with size varying between 1.5 nm and several dozen nanometers. This step is necessary for the phase separation leading to the nanoparticles nucleation.Atom probe tomography (APT) and energy dispersive X-ray mapping in scanning TEM mode, coupled with spectrum imaging on silicon plasmon, were performed to localize the dopant impurities versus the Si-Ncs. The results have showed that n-type (P and As) dopants were energetically favored to be placed into the Si-Ncs core, whereas p-type dopants are preferentially located at the Si-NCs/SiOxNy interface.The effect of composition and post-deposition annealing temperature on the Si-Ncs light-emitting properties was investigated by the examination of photoluminescence (PL) evolution. The dopants distribution profiles within the host matrix were determined by Rutherford Backscattering Spectroscopy (RBS). EFTEM combined with X Rays mapping analysis have exhibited that the incorporation of arsenic at a high doping level (dose of 5x 1016 As/cm2) leads to an increase of the Si-Ncs size by a factor around 4, precisely from 4 nm to more than 20 nm (Figure 1). On the other hand, the EFTEM-X Rays analysis was unable to detect boron dopants in the SiOxNy films. At this doping level, it could be possible to observe a localized surface plasmon resonance (LSPR) 7.For both n- and p-type dopants, the silicon nanoparticles crystalline fraction was found to be much higher than the undoped structures. The dopants facilitate the nucleation and growth of crystalline nanoparticles. This behavior is quite similar to that observed for thin amorphous silicon films. The results have showed that the nanostructures shape have different behaviors depending on the dopants.Finally Schottky diodes were prepared. The I-V characteristic curves show that the electrical conduction in the -doped structures increases with the dopant doses and we obtained a rectifier behavior. The results have showed that the heavily As-doped silicon structures are limited by the tunnel oxide thickness between the large Si-Ncs. These results are very encouraging when aiming at implementing such nanocomposite materials in photovoltaic solar cells.

Novel strategy to improve the tribological property of polymer: In-situ growing amorphous carbon coating on the surface

Surface of ethylene-propylene copolymer (EPC) plastic was continuously treated by carbon plasma in a direct-current magnetron sputtering deposition (DC-MSD) system. Microstructure evolution of the polymer surface with different treating time was analyzed by Diffusive Reflectance infrared Fourier Transform (DRIFT) spectroscopy, Raman Spectroscopy, X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM) and Focus Ion Beam Scanning Electron Microscopy (FIB-SEM), respectively. The adhesion strength and tribological performance were measured by scratch tester and reciprocating ball-on-disc tribometer. Results showed that the bombardment of energetic plasma was capable of activating the surface polymer substrate, which could induce an in-situ transformation from organic carbon to inorganic carbon of the surface layer, following with an epitaxial growth of amorphous carbon upon the in-situ transition layer with the continuous treatment of carbon plasma. This kind of in-situ growing a-C coating on polymer including the in-situ transformation of top layer and the epitaxial growth on in-situ transition layer endow the weak substrate an excellent protective surface with strong adhesion, which exhibited much lower friction and wear. The possible wear mechanism of a-C coatings on polymer substrates was also presented.

Controllable fabrication of self-organized nano-multilayers in copper–carbon films**Project supported by the National Natural Science Foundation of China (Grant Nos. 51472250, U1637204, and 51775537).

In order to clarify the influence of methane concentration and deposition time on self-organized nano-multilayers, three serial copper–carbon films have been prepared at various methane concentrations with different deposition times using a facile magnetron sputtering deposition system. The ratios of methane concentration (CH4/Ar+CH4) used in the experiments are 20%, 40%, and 60%, and the deposition times are 5 minutes, 20 minutes, and 40 minutes, respectively. Despite the difference in the growth conditions, self-organizing multilayered copper–carbon films are prepared at different deposition times by changing methane concentration. The film composition and microstructure are investigated by x-ray photoelectron spectroscopy (XPS), x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and high-resolution transmission electron microscopy (HRTEM). By comparing the composition and microstructure of three serial films, the optimal growth conditions and compositions for self-organizing nano-multilayers in copper–carbon film are acquired. The results demonstrate that the self-organized nano-multilayered structure prefers to form in two conditions during the deposition process. One is that the methane should be curbed at low concentration for long deposition time, and the other condition is that the methane should be controlled at high concentration for short deposition time. In particular, nano-multilayered structure is self-organized in the copper–carbon film with copper concentration of 10–25 at.%. Furthermore, an interesting microstructure transition phenomenon is observed in copper–carbon films, that is, the nano-multilayered structure is gradually replaced by a nano-composite structure with deposition time and finally covered by amorphous carbon.

High quality anti-sticking coating based on multilayer structure

A multilayer Re/Ir coating was deposited on WC substrate by RF magnetron sputtering deposition system. SEM, AFM, XRD, HRTEM, Nano Indenter and contact angle were used to characterize the morphology, micro-structure and anti-sticking property. The results demonstrated that the multilayer Re/Ir coating presented higher anti-sticking property and mechanic performance comparing with the monolayer coatings. The formation of TaC at elevated temperature and coherent boundary between Ta and Ir crystalline were both assumed to impede the further diffusion of C or Co atoms. Moreover, the ordered nanostructure enhanced the bonding between Re and Ir at interface, which made it difficult for Ca, Ba of glass network modifiers elements to penetrate in protective films, and alleviate adhesion of glass at elevated temperature. The motion of edge dislocations and stacking faults were also significantly impeded due to the increase of interfaces and grain boundaries. This restriction probably contributes to improving the mechanical property, which is benefit to the lifetime of mold and the quality of the optical glass product. The wetting angle at high temperature was adopted to evaluate the anti-sticking property of multilayer coating, and shown the coherent results as mentioned before.

Synthesis and characteristics of nc-WC/a-C:H thin films deposited via a reactive HIPIMS process using optical emission spectrometry feedback control

A high-power impulse magnetron sputter deposition system with feedback control using an optical emission spectrometer (OES) is used to deposit nc-WC/a-C:H thin films using a tungsten (W) target material reaction with C2H2 gas in a reactive mode. The plasma emission intensity of W+ ions at an emission wavelength of 429.6 nm is monitored, and the amount of reactive C2H2 gas is precisely controlled in order to maintain stable emission intensity during the deposition process. By controlling the input flow rate of C2H2 and using different W+ ion optical emission intensity set points, various nc-WC/a-C:H thin films are obtained at a fixed duty cycle of 2% and pulse frequency of 133 Hz between deposition temperatures of 70 °C and 75 °C. The characteristics and mechanical properties of the obtained thin films are investigated. The highest peak current and peak power density of 189 A and 706 W/cm2, respectively, are obtained at an OES set point of 10%, which corresponds to a high amount of C2H2 gas injection. When the OES set point is <80%, a phase change from α-W2C to WC1−xis clearly identified using the XRD data. Raman analysis also depicts that a W-doped diamond-like carbon structure (nc-WC/a-C:H) is obtained below an OES set point of 30%. Additionally, the concentration of carbon in the nc-WC/a-C:H thin films is observed to gradually increase from 16.9 to 93.8 at.%, whereas the concentration of tungsten decreases from 78.1 to 5.4 at.% as the OES set point decreases from 90% to 10%. The highest hardness of 32.6 GPa was obtained at an OES set point of 90% when the film was composed of an α-W2C phase. However, the hardness values are observed to decrease as the OES set points decrease.

The influence of superimposed DC current on electrical and spectroscopic characteristics of HiPIMS discharge

The electrical characteristics and spectroscopic properties have been comprehensively investigated in a DC superimposed high power impulse magnetron sputtering (DC-HiPIMS) deposition system in this paper. The influence of superimposed DC current on the variation of target and substrate current waveforms, active species and electron temperatures with pulse voltages are focused. The peak target currents in DC-HiPIMS are lower than in HiPIMS. The time scales of the two main discharge processes like ionization and gas rarefaction in DC-HiPIMS are analyzed. When the pulse voltage is higher than 600 V, the gas rarefaction effect becomes apparent. Overall, the ionization process is found to be dominant in the initial ∼100 μs during each pulse. The active species of Ar and Cr in DC-HiPIMS are higher than in HiPIMS unless that the pulse voltage reaches 900 V. However, the ionization degree in HiPIMS exceeds that in DC-HiPIMS at around 600 V. The electron temperature calculated by modified Boltzmann plot method based on corona model has a precipitous increase from 0.87 to 25.0 eV in HiPIMS, but varies mildly after the introduction of the superimposed DC current. Additionally, the current from plasma flowing to the substrate is improved when a DC current is superimposed with HiPIMS.

Effects of deposition temperature on the electrical properties of Ti/SiC Schottky barrier diodes

Ti Schottky contacts were deposited on n-type 4H-SiC at different temperatures ranging from 28 oC to 900 oC using a magnetron sputtering deposition system to fabricate Schottky barrier diodes. Post deposition annealing at 500 oC for up to 60 hours in vacuum was carried to further improve the contact properties. Optimum barrier height of 1.13 eV and ideality factor of 1.04 was obtained in contacts deposited at 200 oC and annealed for 60 hours. Under a reverse voltage bias of 400 V, the average leakage current on these set of diodes was 6.6 x 10-8 A. Based on the x-ray diffraction analysis, TiC, Ti5Si3 and Ti3SiC2 were formed at the Ti/SiC interface. These results could be beneficial to improving the performance of 4H-SiC Schottky diodes for high power and high temperature applications.

Controllable fabrication of Cu&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;O porous nanostructured films by negative bias deposition method

As one of the most common two kinds of copper oxides, cuprous oxide (Cu2O) is an important p-type transition metal oxide semiconductor material. Due to the advantages of low-cost, non-toxicity and abundant copper sources and the potential applications in the fields of gas sensors, solar cells and photocatalysts, thin films of Cu2O have attracted great interest of researchers. To enhance the performances of the above Cu2O-based surface-sensitive devices and materials, the researchers tend to prepare Cu2O thin films of porous or even nanoporous structures. However, there is still no effective method available for the controllable fabrication of Cu2O porous nanostructured films (or porous nanostructure-films, short for PNFs), which owns not only the common features of porous thin films but also the unique properties of nanosize building units. By using a radio- frequency balanced magnetron sputtering (MS) deposition system, in this paper, Cu2O PNFs were prepared on clean glass slides by applying different negative bias voltage during film deposition. After the preparation, a field-emission scanning electron microscope (FESEM), a grazing-incidence X-ray diffractometer (GIXRD) and an ultraviolet-visible (UV-Vis) spectrophotometer were applied subsequently for the detailed characterizations of surface morphology, texture and optical property respectively. It was observed that the as-prepared Cu2O PNFs exhibited flexible porosities and nanosize building units, which were greatly dependent on the substrate negative bias voltage. In particular, when the substrate bias voltage was kept at −50 or −150 V, the as-prepared Cu2O PNFs both demonstrated intriguing triangular pyramid-like nanostructures with distinct edges and corners on the porous film surface. Further, the side view FESEM images and the out-of-plane GIXRD spectra demonstrated a columnar growth of the Cu2O PNFs with a notable preferential orientation of (111). The optical testing results showed that the band gap of the Cu2O PNFs obtained at different negative bias voltages was tunable between 2.0 and 2.35 eV, which demonstrated a little red or blue shift relative to that of bulk Cu2O (2.17 eV). It is expected that the traditional ion bombardment and re-sputtering theories are not suitable for the explanation of the above bias voltage effects. This is because the traditional ion bombardment and re-sputtering theories were proposed to account for the bias deposition in an unbalanced magnetron sputtering (MS) system rather than the present balanced MS system. Further, the experimentally observed non-linearly changed density or porosity of the Cu2O PNFs with the bias voltage at relatively low values and the common even surface at relatively high values confirmed this viewpoint. Based on the above findings and analysis, a selectively preferential deposition of material atoms or molecules on the film surface during the negative bias deposition was proposed. That is, when the substrate is negatively biased, the tip- charging effect of electrons would occur on the nanoscale rough surface of the substrate or the depositing film. The resulting electric field near the substrate or film surface is non-uniform and could be regarded as an assembly of many electric fields of particle or tip charges. As a consequence, the sputtered atoms or molecules would be acted by two kinds of Coulomb forces: one is the attractive force originating from the electric fields of the closest particles or tips when traveling near the substrate, and the other is the repulsive force coming from the surrounding particles or tips with the same kind of charges after depositing on one particle or tip. For the former force, it would lead to a preferential deposition of sputtered atoms or molecules on the particles or tips and meanwhile provide an additional kinetic energy for the deposited atoms or molecules to migrate or diffuse around; for the later force, the constraint effect of the surrounding electric fields of particle or tip charges would hinder the migration or diffusion of deposited atoms or molecules on the film surface. It is thus expected that the tip charging effect would lead to a columnar growth of films, and the contradictory of the above two forces would influence or even determine the final surface morphology of films which depends on the value of substrate bias voltage.

Oxidation behaviour of CrAlYN coatings at elevated temperatures

CrN/AlN nanolayered coatings with different Y doping levels were deposited to understand the effects of Y on the oxidation behaviour of the coatings at elevated temperatures. The coatings were deposited in a hybrid HIPIMS and magnetron sputtering deposition system, and their chemical composition and mechanical properties were characterized using EDS and nanoindentation tests respectively. The as-deposited coatings were annealed in air at 800°C and 1100°C for 1h, and the evolution of coating microstructure were characterized by GI-XRD and FIB assisted cross-sectional SEM imaging. Different oxidation behaviours were observed at 800°C and 1100°C. At 800°C, coating oxidation is dominated by the formation of Cr2O3, while at 1100°C, the oxidation is characterized by the competing growth of Cr2O3 and Al2O3 scales. The Y content significantly influenced the oxide scale formation and voids distribution in the coatings, and this was attributed to the role of Y in changing the diffusion processes both within the coating and at the coating-air interface.

Magnetron Sputtering System for Deposition of Multinanolayered Coatings With Reactive Gas Activation in Microwave Discharge

The design of a dual gas magnetron system for ion sputtering of two source materials with an activation of a reactive gas in the remote microwave (MW) discharge for the deposition of multinanolayered coatings is presented. The design of the reactive gas activator with the electron cyclotron resonance was realized on the basis of the analysis of possible schemes for the formation of MW gas discharge plasma systems. The vacuum electron magnetron is used as a MW generator (2.45 GHz and ~800 W). Geometry of the electrodynamic part of the activator was selected by means of simulation with Comsol Multiphysics. The practical examination of the dual sputtering system was carried out by sputtering of Ti and B 4 C targets, while nitrogen was used as the reactive gas. The characteristics of the multinanolayered Ti-B-C-N coatings were studied and it was determined that the deposited coatings had the nc-TiN x /(a-BN+a-C) structure. The Knoop hardness of the coatings was found to be ~45 GPa, while the nanohardness was lower than Knoop ones by ~20%-30%. The presented sputtering system could be recommended for deposition of wear-resistant and protective coatings.

Effect of an optical emission spectrometer feedback-controlled method on the characterizations of nc-TiC/a-C:H coated by high power impulse magnetron sputtering

An optical emission spectrometer (OES) feedback-controlled high power impulse magnetron sputter deposition system was used to deposit nc-TiC/a-C:H thin films in a reactive mode. The plasma emission intensity of Ti2+ ions at the emission wavelength of 365nm was monitored and the amount of reactive C2H2 gas was precisely controlled to maintain stable emission intensity during the deposition process. By controlling the C2H2 input flow rate and different Ti2+ ion optical emission intensities, various nc-TiC/a-C:H thin films were obtained at a fixed duty cycle of 2% and repetition frequency of 500Hz at 75°C. The characteristics and mechanical properties of the obtained films were also investigated. As the OES set point was 40%, the phase changing from TiC to nc-TiC/a-C:H films was clearly identified. The highest hardness of 26GPa was obtained at the OES set point of 40%, where the film was composed of TiC. In addition, the lowest friction coefficient of 0.08 was obtained at the OES set point of 7%, which represented the nanocomposite structure of nc-TiC/a-C:H films.

Fatigue resistant carbon coatings for rolling/sliding contacts

The growing demands for renewable energy production have recently resulted in a significant increase in wind plant installation. Field data from these plants show that wind turbines suffer from costly repair, maintenance and high failure rates. Often times the reliability issues are linked with tribological components used in wind turbine drivetrains. The primary failure modes in bearings and gears are associated with micropitting, wear, brinelling, scuffing, smearing and macropitting all of which occur at or near the surface. Accordingly, a variety of surface engineering approaches are currently being considered to alter the near surface properties of such bearings and gears to prevent these tribological failures. In the present work, we have evaluated the tribological performance of compliant highly hydrogenated diamond like carbon coating developed at Argonne National Laboratory, under mixed rolling/sliding contact conditions for wind turbine drivetrain components. The coating was deposited on AISI 52100 steel specimens using a magnetron sputter deposition system. The experiments were performed on a PCS Micro-Pitting-Rig (MPR) with four material pairs at 1.79GPa contact stress, 40% slide to roll ratio and in polyalphaolefin (PAO4) basestock oil (to ensure extreme boundary conditions). The post-test analysis was performed using optical microscopy, surface profilometry, and Raman spectroscopy. The results obtained show a potential for these coatings in sliding/rolling contact applications as no failures were observed with coated specimens even after 100 million cycles compared to uncoated pair in which they failed after 32 million cycles, under the given test conditions.

Process controllability of inductively coupled plasma-enhanced reactive sputter deposition for the fabrication of amorphous InGaZnOx channel thin-film transistors

The process controllability of inductively coupled plasma-enhanced reactive sputter deposition for the fabrication of amorphous InGaZnOx (a-IGZO) channel thin-film transistors (TFTs) was investigated. a-IGZO film deposition with the addition of H2 gas was performed using a plasma-assisted reactive sputtering system to control the oxidation process during a-IGZO film formation by balancing the oxidation and reduction reactions. Optical emission spectroscopy measurements indicate the possibility for the oxidation reaction to be inhibited by a decrease in the density of oxygen atoms and the reduction effect of hydrogen during a-IGZO film deposition due to the addition of H2 gas. The characteristics of TFTs fabricated using a-IGZO films deposited with a plasma-enhanced magnetron sputtering deposition system were investigated. The results indicate the possibility of expanding the process window by controlling the balance between oxidation and reduction with the addition of H2 gas. TFTs with a-IGZO films that were deposited with the addition of H2 gas exhibited good performance with a field-effect mobility (μFE) of 15.3 cm2 V−1 s−1 and a subthreshold gate voltage swing (S) of 0.48 V decade−1.

Industry-relevant magnetron sputtering and cathodic arc ultra-high vacuum deposition system for in situ x-ray diffraction studies of thin film growth using high energy synchrotron radiation.

We present an industry-relevant, large-scale, ultra-high vacuum (UHV) magnetron sputtering and cathodic arc deposition system purposefully designed for time-resolved in situ thin film deposition/annealing studies using high-energy (>50 keV), high photon flux (>10(12) ph/s) synchrotron radiation. The high photon flux, combined with a fast-acquisition-time (<1 s) two-dimensional (2D) detector, permits time-resolved in situ structural analysis of thin film formation processes. The high-energy synchrotron-radiation based x-rays result in small scattering angles (<11°), allowing large areas of reciprocal space to be imaged with a 2D detector. The system has been designed for use on the 1-tonne, ultra-high load, high-resolution hexapod at the P07 High Energy Materials Science beamline at PETRA III at the Deutsches Elektronen-Synchrotron in Hamburg, Germany. The deposition system includes standard features of a typical UHV deposition system plus a range of special features suited for synchrotron radiation studies and industry-relevant processes. We openly encourage the materials research community to contact us for collaborative opportunities using this unique and versatile scientific instrument.

Low-temperature formation of amorphous InGaZnOx films with inductively coupled plasma-enhanced reactive sputter deposition

A plasma-enhanced sputter deposition system has been developed via enhancement of target sputter discharge with inductively coupled RF plasma (ICP) driven by multiple inner-type low-inductance antennas (LIAs). The advantage of fine control of reactivity during the deposition is of great significance for the deposition of a transparent amorphous oxide semiconductor films, amorphous InGaZnOx (a-IGZO), whose electrical properties are significantly sensitive to the reactivity of the films with oxidation species during the film deposition. The characteristics of thin-film transistors (TFTs) fabricated with an a-IGZO film using the plasma-enhanced magnetron sputter deposition system have been investigated. The a-IGZO channel TFTs fabricated using the plasma-enhanced reactive sputtering system at a substrate temperature as low as or lower than 150 °C exhibited a good performance of μFE = 18.5 cm2 V−1 s−1.

Sputtered Ag thin films with modified morphologies: Influence on wetting property

Silver thin films with thickness ranging from 3nm to 33nm were sputter deposited onto silicon wafers and tungsten layers. Those W layers were previously synthesized in the same DC magnetron sputter deposition system with various experimental conditions (argon pressure, target to substrate distance) in order to stabilize different surface morphologies. SEM observations and AFM images showed that the growth mode of Ag films is similar on Si substrates and on the smoothest W layers, whereas it is modified for rough W layers made of sharp grains. The effect of the W layer morphology on Ag film growth was clearly evidenced when the deposition took place at high temperature. It is seen that performing the deposition onto substrates of various morphologies allows tailoring the wetting property of the Ag deposit.

Plasma sputtering as a novel method for improving fastness and antibacterial properties of dyed cotton fabrics

Improving the fastness properties and antibacterial activity of dyed cotton samples is the main goal of this research work. First, cotton fabrics were dyed with various types of dyestuffs such as direct, vat, and reactive. Then, prepared samples were sputtered using plasma sputtering system for 15 s by silver and copper. In this study, we have used a DC magnetron sputtering system for deposition of metal nanolayer on the surface of samples. Samples were placed on the anode. The cathode particles were scattered by attacking active ions, radicals, and electrons. After plasma treatment, the reflection factor of sputtered samples was measured using reflective spectrophotometer. Also wash and light fastness properties of both sputtered and non-sputtered samples were compared according to ISO standards. The antibacterial efficiency was determined by bacterial counting test. The antibacterial properties of the fabrics were connected with the presence of metal on their surface. Silver or copper particles were deposited on the surface of cotton samples, and the antibacterial activity has been developed, through incorporation of metal nanoparticles on fabric surfaces. The results show that sputtering technique can be a novel method for improving the fastness properties of dyed cotton samples.

Angle-resolved investigation of ion dynamics in high power impulse magnetron sputtering deposition system

The high power impulse magnetron sputtering deposition system (HiPIMS) equipped with 5cm in diameter titanium target has been investigated by means of time-resolved modified Katsumata probe. The probe allows for determination of the ion velocity distribution function. However, the modified Katsumata probe is unable to resolve the mass of ions. On the other hand, compact construction of modified Katsumata probe allows us to place the probe in an arbitrary position with respect to planar magnetron. The present construction of modified Katsumata probe allows reaching the acceptance angle of about 15°. The ion velocity distribution function (IVDF) in forward direction is then directly proportional to the derivative of measured ion current with respect to the retarding potential. An angle-resolved study of HiPIMS system operating in the reactive atmosphere has been carried out. The effect of oxygen partial pressure on measured IVDF at different angles within the plasma pulse has been investigated. The total pressure was held at 1Pa together with the constant pulse-on time of 100μs, pulse frequency of 100Hz and mean discharge current of 500mA for all the experiments. The results revealed inhomogeneous ion fluxes in different directions from the target especially for reactive atmosphere. The IVDFs measured at angle 45° demonstrated significantly enhanced energy tail in contrast to dc magnetron or mid-frequency pulsed-dc magnetron. Furthermore, higher oxygen partial pressure indicated broader IVDF for all the angles together with a slight shift of IVDF peak to negative values indicating the negative plasma potential.