Cylindrical Magnetron Sputtering Research Articles

Adhesion and growth of titanium nitride coating deposited on AISI 316L using cylindrical magnetron sputtering

ABSTRACT This study explores the efficacy of plasma etching for AISI 316L stainless steel (SS), in improving the adhesion of titanium nitride (TiN) coatings. Due to the presence of an oxide layer on SS, as deposited TiN coatings typically exhibit poor adhesion. Here, varying duration of plasma etching was employed to assess TiN coating adherence to the SS. The TiN coatings were deposited onto the SS substrate via cylindrical magnetron sputtering technique. Surface roughness value of ~10 nm was obtained on SS post 60 minutes plasma etching compared to unetched SS sample ~4 nm which was evaluated using Atomic Force Microscopy. X ray Diffraction analysis of the TiN coating after plasma etching revealed a preferred growth of the TiN (111) phase. Adhesive strength of the TiN coating was assessed through scratch testing. Scanning electron Microscopy was employed to analyze the surface morphology of the TiN coating and its failure phenomena post scratch testing. A comparative analysis of TiN coatings on various plasma etched SS surfaces highlighted the direct influence of the surface condition on growth, surface morphology, and roughness. Notably, 60 minutes etching duration yielded the highest adhesion strength of 0.94 N for the TiN coating on SS, contributing to its enhanced corrosion resistance properties.

Influence of topography on nano-mechanical properties of cylindrical magnetron sputtered TiN films

Numerous studies on Nano-mechanical behavior of the thin films explained primarily in terms of their film morphology and particle size rather than film topography. Therefore, the current study investigates the effect of film topography on the nano-mechanical characteristics of the film. Ti/TiN multilayer thin films were deposited at varying deposition pressures by using an indigenously developed Cylindrical Magnetron Sputtering (CMS) unit. Surface crystallographic information is characterized by synchrotron-based Grazing Incidence XRD analysis. Film growth follows self-assembled nano hill architecture as revealed by AFM and in situ Scanning Probe Microscopy images. The tribo-mechanical properties of the film is dependent on the height and spacing of its self-assembled structure, which experiences either crushing or buckling under the indenter load, thereby affecting film characteristics. Film deposited at moderate pressure exhibits superior wear behavior, attributed to the interplay between Plasticity Index (PI) and Depth Recovery Ratio (DRR). The study primarily focused on film growth phenomena by using cylindrical targets and their influence on nanomechanical properties of the film.

Commissioning of a two-target DC cylindrical magnetron sputter coater for depositing Nb₃Sn film on Nb superconducting radiofrequency cavities

A DC cylindrical magnetron sputter coater was commissioned and used to coat Nb 2.6 GHz superconducting radiofrequency (SRF) cavity with Nb3Sn. The sputter coater has two identical cylindrical magnetrons that can move, with a controlled speed, along the axis of the SRF cavity to coat the inside surface of the cavity. The design of the sputter coater is discussed, along with its performance. Initially, a sample holder that allows coating on flat substrates at positions similar to the equator and beam tubes of a 2.6 GHz SRF cavity was used to test conditions for fabricating Nb3Sn layers. Multilayers of Nb and Sn were sequentially sputtered on flat Nb and sapphire substrates mounted on the equivalent positions of the cavity's beam tubes and the equator using the two identical cylindrical magnetrons. Then, the Nb/Sn multilayers were annealed at 950 °C for 3 h. The ∼1.2 μm thick Nb3Sn film did not show any other Nb–Sn compounds and had a superconducting transition temperature of 17.61–17.76 K. The 2.6 GHz SRF cavity was coated using similar conditions as flat samples. Cryogenic RF testing of the Nb3Sn-coated cavity demonstrated a quality factor of 3.2 × 108 at an accelerating gradient of 5 MV/m at 4.4 K.

ANALYSIS OF METHODS FOR INCREASING THE SURVIVABILITY OF SMALL ARMS AND CANNON BARRELS BY THE APPLICATION OF CHROME COATINGS

This paper is an analysis of modern chrome coating technologies for the barrels of small arms and cannons. Barrel survivability refers to the ability of a weapon system to fire a certain number of rounds without significant deterioration in ballistic characteristics. There are various methods to provide the necessary survivability of the barrels, both technological and constructive. This paper will consider technological methods, in particular chroming technologies. The objects of the research are various methods of chromium coating: electrolytic, cylindrical magnetron sputtering, galvanic honing, cathode-mechanical chromium plating, and thermodiffusion saturation by chromium. Electrolytic chrome plating in baths is the most common method, however it has significant drawbacks - toxic waste, difficulty in providing uniformity and integrity of plating, hydrogen release during plating, the need for subsequent heat treatment of the barrel. Coating barrels with cylindrical magnetron sputtering is one of the least studied methods, but from the available materials we can note the reduced toxicity and the absence of hydrogenation of the barrel and the plating. Nevertheless, the adhesion of the coating material and the barrel should be investigated. Analysis of the thermodiffusion chrome saturation method is also a promising method. However, a reduction in temperature during the coating process and subsequent normalization of the coating is necessary. This method is currently being investigated in the "Special purpose product technology" laboratory at the Azerbaijan Technical University. As a result of the research, the most prospective methods can be considered galvanic honing, the cathodic-mechanical method and thermodiffusion chrome saturation. The advantages of these methods are increased productivity and quality of the plating surface. In addition to the prospective chrome plating methods, the paper also noted questions for which the answers remain open. Keywords: barrel, coating, chromium plating, wear, electroplating, magnetron sputtering, diffusion.

Influence of cylindrical magnetron sputtering configurations on plasma characteristics

ObjectiveIn the present paper, the influence of cylindrical magnetron configurations on the fundamental plasma parameters of the axial magnetic field was described in more detail. MethodsThe chamber of this system has consisted of two coaxial cylinders which are used as the electrodes of the system with the magnetic solenoid coil present in the outer cylinder to generate the axial profile of the magnetic field at different coil currents (from 2 A to 8 A). The plasma parameters of the normal glow discharge region are diagnosed. ResultsThe results showed that the cylindrical magnetron configurations had a significant impact on the characteristics of the normal glow regions. The cylindrical magnetron configurations have slight effect on the axial profile of E × B drift velocity and the cyclotron frequency. By changing the configuration plasma parameters (The electron temperature, electron number density, and Debye length) their values changed.

Ultra-conductive wires with cascaded carbon nanotube/Cu structure

In the present study, ultra-conductive wires were produced by the cascaded Cu/MWCNT wire structure. Cascaded wires were prepared on the industrial 1 mm diameter Cu wire with two steps; Firstly, electrophoretic deposition (EPD) was used to deposit the functionalized MWCNT on the Cu wires. Secondly, a novel inverted cylindrical magnetron sputtering (ICMS) has been built to coat Cu on the MWCNT deposited Cu wire. Different number of cascaded layers up to 13 layers of Cu/MWCNT wires as well as different Cu coating parameter were produced. High deposition rate of MWCNT on Cu wires has been achieved by the EPD method. As can be seen from the cross-sectional SEM images, the intended cascaded structures were successfully formed. The ampacity of the 1 mm industrial Cu wire used in this study has increased by 9.2%. In addition, the temperature of the cascaded wires has shown slow increase compared to that of reference Cu wire. On the other hand, the maximum current able to carry with 1 °C temperature raise has increased by 50%.

Deposition of TiN and TiAlN Thin Films on Stainless Steel Tubes by a Cylindrical Magnetron Sputtering Method

Abstract Titanium nitride (TiN) and titanium aluminum nitride (TiAlN) coatings are very hard materials that are mostly coated on cutting tools to increase the tool life. These coatings have also been successfully applied as a coating material for biomedical applications mainly due to their tribological properties, biocompatibility, and affordable price. In an attempt to develop transition metal nitride coatings on specimens of cylindrical geometry, TiN and TiAlN thin films were deposited successfully on stainless steel tubes using a direct-current cylindrical magnetron cosputtering method. Both types of coatings were uniform in nature and had good adherence to the substrate. TiN and TiAlN thin films were characterized systematically to determine their structure, surface morphology, chemical states, chemical structure, and electrochemical behavior using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and potentiodynamic methods, respectively. The XRD patterns of the TiN and TiAlN coatings indicated (111) preferential orientation. Cross-sectional SEM images revealed a columnar growth of the coatings with an arrow-headed geometry. XPS characterization showed the presence of TiN, Titanium dioxide, titanium oxynitride, aluminum oxide, and aluminum nitride phases. Potentiodynamic polarization tests in 3.5 % sodium chloride solution revealed that the TiAlN coating exhibited superior corrosion resistance compared with the TiN coating. Furthermore, TiAlN coating showed 94 % of average absorption in ultraviolet-visible region using photospectrometry. The cylindrical magnetron sputter deposition technique enables development of uniform protective coatings on tubular geometries, which are frequently employed in solar thermal and nuclear applications.

Comparative study of discharge characteristics and associated film growth for post-cathode and inverted cylindrical magnetron sputtering

In this study, an experimental investigation of a DC cylindrical magnetron discharge for argon gas in post-cathode (i.e. direct) and hollow-cathode (i.e. inverted) configurations was carried out. The discharge properties at different externally applied magnetic fields and operating pressures were measured and compared for both the configurations. The discharge current (I)–voltage (V) characteristics obey $${I\propto V^n}$$ , where the value of n is in the range of 3–8. The discharge current increases linearly with the magnetic field in the post-cathode configuration, whereas it saturates at higher magnetic fields in the case of inverted configuration. Measurement of plasma potential indicated a considerable anode fall in the inverted magnetron configuration, whereas a negligible anode fall and strong cathode fall were observed in the case of post-cathode configuration. The plasma density and electron temperature, measured using a double Langmuir probe, were observed to be higher in the inverted magnetron configuration. The plasma density was found to be maximum at around 3–4 cm away from the respective inner electrode in both the configurations. A clear change in surface morphology of copper thin film was observed in the case of inverted magnetron configuration, which might be due to the extra ionisation near the anode owing to the anode fall.

Negative permittivity and permeability of gold nanostructured thin films in UV–vis region

In this article, we report the growth of gold nanorods on glass substrates and copper nanoparticle thin films by cylindrical direct current magnetron sputtering (CDCMS) at room temperature. The grown gold nanorods have short lengths of < 20nm and show negative optical parameters in UV-Vis region. So far negative permittivity and permeability were only shown for complex artificial structures. In a case of simple structures like gold nanorods, the negative optical parameters were only predicted by simulation methods and considering ideal structures and they were not yet reported by experimental groups, who has grown or synthesis gold nanorods by physical or chemical methods. The small size of gold nanorods and thickness of our samples compare to other experimental groups could be the reason of negative permittivity and permeability in our case. Low loss metamaterials with simultaneously negative permittivity and permeability are desired for practical applications in many optical devices such as optical switching, waveguides, modulators, and plasmonic antenna arrays. The optical properties of the grown gold nanorods were defined by ultraviolet- visible (UV-Vis) spectroscopy and their quality was assessed through multi-technique characterization using transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), and energy dispersed X-ray (EDX).

Mechanical properties of Ta-Al-N thin films deposited by cylindrical DC magnetron sputtering: Influence of N2% in the gas mixture

Ta-Al-N thin films were deposited by cylindrical DC magnetron sputtering on a stainless steel substrate under varying nitrogen flow ratios ( N2 with respect to N2 + Ar in the range of 1.5%-9%. The effect of the N2 content in the reactive gas mixture on crystalline structure, surface morphology, and mechanical properties of Ta-Al-N thin films was investigated. The amount of Al and Ta in deposited films was obtained by energy dispersive X-ray spectroscopy (EDX) analysis and films thickness was measured by surface step profilometer. X-ray diffraction analysis (XRD) revealed that the crystalline structure of the Ta-Al-N polycrystalline thin film is a mixture of TaAl, TaN, and AlN crystalline phases. Surface morphology, roughness, and grain size were investigated by atomic force microscopy (AFM). The nano hardness of Ta-Al-N thin films, measured by the nanoindentation method, was about 9GPa maximum for samples prepared under 3% N2 , and the friction coefficient, obtained by nanoscratch analysis, was approximately 0.2 for all Ta-Al-N thin films. Other results were found to be affected considerably by increasing the N2 amount.

Optical Enhanced Transmission of Double Layer Ultrathin Metallic Films.

Double layer ultrathin metallic films composed of an aluminum film with thickness of 33 nm on copper films with thickness of 16 nm or 32 nm were deposited on polyester foil by cylindrical medium frequency magnetron sputtering in turn. Transmittance and reflectance of these films were measured and compared to each composite film, as well as absorptance, respectively. The results show that the reflectance increases, while both the transmittance and the absorptance decrease with the increase in copper film thickness. At the same time, the three optical parameters of the double layer film were calculated theoretically. Compared to theoretical results, there is an increase in transmittance, while a decrease in reflectance and absorptance for the double layer on experimental results. It is concluded that the optical properties of the double layer films are not simply the sum of the two composite films, there is an enhanced transmission effect to electromagnetic wave at the double layer metallic film.

Improving the Thermal Stability of Cu3N Films by Addition of Mn

Mn-doped Cu3N films were deposited by cylindrical magnetron sputtering equipment on the common glass at room temperature. The incorporation of Mn can change the preferred growth orientation from Cu-rich plane (111) to N-rich plane (100) due to the improvement of nitridation of Cu. The shrinkage of the lattice and the X-ray photoelectron spectroscopy results reveal that Mn should replace Cu atoms in the lattice or be segregated in the grain boundaries. The thickness of Mn-doped film is smaller than that of the pure one due to the less physisorption of N species among the columnar grains. The mean grain size and the energy gap become larger with increasing Mn concentration to 2.2 at.% and then decrease when the concentration of Mn is higher than 2.2 at.%. Notably, weak doping of 1.5 at.% Mn successfully promotes the decomposed temperature by ∼50 °C. According to the results of XRD and SEM for Mn-doped films annealed in vacuum, a possible decomposed mechanism with increasing the annealing temperature is proposed.

Industrial-scale deposition of highly uniform and precise optical interference filters by the use of an improved cylindrical magnetron sputtering system

The manufacture of precision optical interference coatings requires a process with sufficient accuracy, precision, uniformity, and stability to produce economic quantities of coatings with acceptable yield. This paper compares the capabilities of the plasma assisted reactive magnetron sputtering (PARMS) process with the compound-assisted reactive sputtering process (CARS). Compared with PARMS, CARS exhibited superior process accuracy, stability and uniformity by being less sensitive to equipment and process temperatures, and to cathode and machine conditioning. A uniformity deviation of less than ±0.15% is demonstrated for different optical multilayer filters over substrates of 200mm diameter. The CARS process stability and precision are also demonstrated using many coating runs of a sensitive, broadband antireflective coating without the need for optical monitoring. Thus, it is shown that CARS combines the advantages of the Metamode (high stability) and the PARMS process (low optical absorption).

New experimental setup for metallic clusters production based on hollow cylindrical magnetron sputtering

Nanoscale structures have been widely studied because their properties differ greatly from their bulk counterpart systems, raising both a fundamental and technological interest. Despite the great advances that have been made, the domain still presents great challenges. The development of dedicated instrumentation, in particular, is an essential issue since the well established techniques used for atomic size and for macroscopic systems are often not suited for the study of nanoaggregates. In this article, the authors present the development of a new cluster source aimed to produce pure or alloy metallic clusters ranging from two up to thousands atoms in a controllable way. The setup is based on the design of Haberland et al. [J. Vac. Sci. Technol. 12, 2925 (1994)] with the implementation of an hollow cylindrical sputtering as atoms source that enhances the control over the production of alloy clusters and also improves target usage.

Effect of Seed Layer Deposition, Au Film Layer Thickness and Crystal Orientation on the Synthesis of Hydrothermally Grown ZnO Nanowires

Zinc Oxide (ZnO) nanowires were produced by using the seed layer deposition, RF cylindrical magnetron sputtering and sol-gel spin coating techniques. The ZnO seed layer films were characterized by atomic force microscopy (AFM) and ellipsometry. The ZnO nanowires were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM) and X-ray diffraction (XRD). Deposition of ZnO seed layer films using the RF cylindrical magnetron sputtering technique produced the best aligned c-axis orientated nanowires with uniform dimensions. An increase in the gold (Au) film layer thickness produced nanowires of smaller diameter and less orientation in the c-axis. Polycrystalline Au film layer increased the mean diameter of the ZnO nanowires without effecting the c-axis orientation. This study provided valuable information in controlling the dimensions and alignment of ZnO nanowires. Keywords: Hydrothermal growth, seed layer deposition, ZnO nanowires.

Effect of N2/Ar on structure and hardness of TaN-Ag thin films deposited by DC cylindrical magnetron sputtering

TaN-Ag thin films were deposited on a 304 stainless steel substrate by cylindrical DC magnetron sputtering using different ratios of nitrogen to argon gas. The N2 percentages were 1.5%, 3%, 4.5%, 7.5%, 10.5% and 15% by volume. The influence of the N2/Ar ratio on the films morphology, structure and hardness was investigated using Atomic Force Microscopy (AFM), Grazing Incidence X-ray Diffraction (GIXRD), and the nanoindentation method. The amounts of Ta and Ag were determined using Energy Dispersive X-ray Spectroscopy (EDS). The thickness of the deposited films was measured by surface step profilometer. The RMS surface roughness increased for N2 percentages up to 7.5% and then decreased. Grazing results showed different TaN phases and Ag crystalline structures. The hardness of all films was much higher than the hardness of bulk silver or tantalum. The highest hardness value was obtained for 1.5% N2 . The EDS results indicated that the Ag/Ta ratio in the deposited films increases with increasing the N2 amount from 1.5% to 15%. The size of Ag islands on the surface was maximized at 7.5% N2 in the gas mixture. The thicknesses of films were in the range of 400-600 nm.

Elaboration of a wide range of TiO2 micro/nanostructures by high power impulse inverted cylindrical magnetron sputtering

An inverted cylindrical magnetron sputtering reactor mode was used for TiO2 thin films deposition. The high voltage was delivered to the target in dc mode and in pulsed mode at low frequency (250 Hz) to reach high power impulse magnetron sputtering (HiPIMS) regimes and obtain subsequent higher plasma ionization rates. Time-resolved electrical and optical characterizations of the discharge were performed and the layer's chemistry, morphology and microstructure were characterized using x-ray photoelectron spectroscopy, scanning electron microscopy, atomic force microscopy, x-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) analysis. In accordance to the conclusions described in the literature for TiO2 HiPIMS deposition in planar configuration, it is shown that the increase of peak target current (induced by the decrease of the duty cycle at constant average power) leads to smoothening and densification of the layers. The microstructure of the coatings is also strongly influenced by the energy and the flux of the incoming species to the substrate. XRD experiments show that passing from dc to HiPIMS mode leads to a transition from anatase to rutile formation, but HRTEM analyses allows one to highlight that the proportion of amorphous domains is also increased when increasing the energy delivered to the growing film. It results in the obtaining of layers with globular structure composed of rutile nano-crystallites embedded in an amorphous matrix.

Study on the structure, morphology and properties of Fe-doped Cu3N films

Fe-doped Cu3N films were prepared by cylindrical magnetron sputtering equipment at room temperature. The doping of Fe with the proper concentration results in a change in the preferred growth orientation from the Cu-rich plane (1 1 1) to the N-rich plane (1 0 0), which relates to the evolution of the surface grain shape from pyramid to sphere. Excessive doping of Fe is not favourable for the crystallization of Cu3N films. The cross-sections of the doped films with preferred growth orientations of [1 0 0] exhibit regular columnar grains. The variation between the lattice constant and the XPS results reveals that Fe probably replaces the position of Cu atoms in the lattice or is segregated in the grain boundaries. Weaker bonding of Cu–N results in a reduction of thermal stability for Fe-doped Cu3N films. And the incorporation of Fe can effectively modify the energy gap. According to the variations in the mean grain size, the peak of N1s and the energy gap, it is inferred that a doping limitation exists around 2.0 at%.

Effect of Substrate Bias Voltage on the Physical Properties of Zirconium Nitride (ZrN) Films Deposited by Mid Frequency Reactive Magnetron Sputtering

Present work involves the preparation of Zirconium Nitride thin films on stainless steel (SS) (304L grade) substrate by reactive cylindrical magnetron sputtering method. The X-ray diffraction (XRD) profile of the ZrN thin films prepared with different bias voltage conforms face centered cubic structure with preferred orientation along the (111) plane at lower bias voltage (100 V) and at higher bias voltage (300 V) the preferred orientation shifted to (220) plane. The influences of bias voltage on the thickness and microhardness ZrN thin films have been studied. ZrN thin film sputtered with 300 V bias voltage shows the maximum reflectance of 90% at a wavelength of 1000 nm. The coated substrates have been found to exhibit improved corrosion resistance compared to the SS plate. The root mean square surface roughness and surface morphology were investigated from 3D atomic force microscope (AFM) images and scanning electron microscope (SEM), which indicate smooth and uniform surface pattern without any pin holes.

High-rate deposition of AlTiN and related coatings with dense morphology by central cylindrical direct current magnetron sputtering

An industrial coating equipment, routinely used for the deposition of wear protection coatings on tools by means of vacuum arc evaporation with rotating cylindrical cathodes, has been modified for direct current (DC) reactive magnetron sputtering. We use a central cylindrical magnetron to achieve high-rate deposition of dense hard AlxTi1−xN, AlxCr1−xN, TiN and related coatings. With a DC power of 25kW and one-fold rotation of the tools, the resulting deposition rate is 10μm/h over a total area of 0.3m2, resulting in the high throwing power of more than 3μm·m2/h. Scanning electron microscopy studies show no columnar morphology, but instead a dense fibrous one. Investigations with transmission electron microscopy at higher resolutions revealed a fine fibrous-like (diameter of about 25nm) and extremely dense microstructure, with the axis of the fibers oriented in the direction of the film growth. Atom probe tomography studies confirmed the dense microstructure exhibiting no change in the Al/Ti ratio across the column boundaries over an investigated length of about 200nm. The load-invariant hardness of the Al0.57Ti0.43N coatings reached a value of 33.4±1.5GPa, and the elastic modulus amounted to 466±15GPa. The surface of the deposited coatings is very smooth with average roughness Ra=0.06μm and maximum roughness Rz=0.72μm. The coatings deposited on tools show excellent cutting performance.