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We present the magnetic properties of three-bilayer superlattices [Co(0.8 nm)/Cu(1.1 nm)]3 and Co(0.8 nm)/Al(2.2 nm)]3 grown by magnetron sputter deposition on SiO2 substrates. Using the surface magneto-optical Kerr effect we observed longitudinal magnetic hysteresis loops with low coercivity values of

s Effects of the oxygen partial pressure within the Ar process plasma and the annealing treatment on the properties of magnetron sputtered In0.025Cd0.975O films were investigated in detail. It was observed that the electrical resistivity drastically increases with the oxygen addition, from 4.8 × 10−5 Ω∙cm at [O2] = 0% to 5.5 × 10−3 Ω∙cm at [O2] = 100%, and the carrier concentration and the electron mobility substantially decreased. It was also observed that the resistivity slightly decreased by the vacuum annealing but increased by the annealing in pure oxygen. Detailed characterization indicated that concentration of the oxygen vacancy (VO) donor is reduced and the oxygen interstitial (Oi) acceptors are formed within the samples grown in the O2-mixed ambient. It was proposed that the electrical properties of the InCdO films may be reasonably explained by the compensation model involving VO, Oi, In dopants, and/or their acceptor-like complexes.

Spatial distribution of highly energetic negative ions inherent in magnetron sputtering of oxides has long made low temperature deposition unsuitable for high quality films uniform over relatively large areas. Here we examine the distributions of structure as well as physical properties of magnetron sputtered Al-doped ZnO (AZO) films deposited at low temperatures (≤393 K) in which the bombardment from the negative oxygen ions was systematically studied by changing the discharge voltage (i.e., ion energy) and the substrate position (i.e., ion flux). The film structure was characterized by X-ray diffraction, Raman spectroscopy, and transmission electron microscopy; and the electrical and optical properties were obtained by a Hall system and Spectroscopic Ellipsometry. We found (i) that uniform yet high crystallite quality films can be obtained only when the energy of the negative ions was set below a threshold; (ii) that the ion flux exerted an ever-decreasing effect on modifying the film structure as the ion energy was reduced; and (iii) that a set of structural criteria, incorporating crystallite quality (orientations, size, lattice spacing) and point defects, were derived for low resistivity AZO films. The benefit of lowering the ion energy is then explained in terms of the favorable competition between radiation-induced defect generation and the subsequent dynamic annealing. These findings may pave a way for large-area coating of high quality AZO films at low temperatures.

Magnetron sputter deposited Mo thin films are frequently used as part of the metallization of thin film transistors. To ensure technological applications these Mo thin films are often combined with Al thin films, but are inherently brittle compared to the electrical charge carrying ductile Al thin films. To improve the fracture behavior of bilayered stacks containing Mo layers for future flexible devices like rollable or foldable displays, an optimum ductile/brittle layer thickness ratio is necessary. Within this work the electro-mechanical behavior of bilayered Al/Mo thin films grown by dc magnetron sputter deposition on polyimide substrates under tensile strain was investigated. Various Al/Mo layer thickness ratios (1:1, 3:1, 5:1 and 10:1), all with a base Mo film of 30 nm were tested. In situ tensile tests combining electrical 4-point probe resistance and optical measurements revealed an optimum thickness ratio between 5:1 and 10:1 for the crack onset strain. Post mortem analysis on the crack morphology revealed that higher thickness ratios better compensate cracks by leaving wider subsurface pathways for electron conduction of the layer stack than lower thickness ratios.

A special design of the structure of magnetron sputtering equipment is proposed to facilitate the deposition of uniform films on non-planar surfaces with a small target. A guide rail is used to adjust the inclination of the target in combination with the rotation and vertical movement of the substrate holder to achieve step-by-step coating. A calculation model is proposed to simulate the effects of target-substrate distance, experiment condition coefficient, magnetron racetrack area, and staying time on the film deposition rate and thickness distribution. The relationship between the experimental parameters and theoretical tolerance values was also established in this design. Uniform films were deposited on a substrate having a diameter and height of 160 mm with a 2 in. Ti target. Measurement results show that the relative thickness distribution is less than ±3%, which agreed well with the calculation, demonstrating that the model is applicable for depositing uniform films on large convex surfaces. In addition, this calculation model provided a possible method to deposit uniform films on other surface sizes and types.

The effect of the low Ti content on the phase composition, structure and mechanical properties of magnetron sputtered WB2 - TiB2 films was studied. Non-equilibrium conditions during the films deposition cause the difference of their phase composition from the composition of the target. Sputtering of a WB2 target (hexagonal crystal lattice) results in formation of the β-WB phase with an orthorhombic crystal lattice and a B/W atoms ratio of about 1.19. It was found that even a very low Ti content (about 0.6 at. %) act as a catalyst for the formation of a diboride phase with hexagonal crystal lattice. A nanocomposite β-(W,Ti)B/(Ti,W)B2 (where (Ti,W)B2 has a hexagonal crystal lattice) is formed in the range of 0.6

Tantalum nitride (TaN) films were deposited onto SiO2/Si and multilayer ceramic (MLC) substrates with a reactive direct current magnetron sputtering method. After they were kept at different N2 partial pressures and substrate temperatures, these were characterized for their electrical, structural, and mechanical properties for use as thin film resistors (TFRs). Results of X-ray diffraction analysis, observation of microstructure, sheet resistance measurement, and accelerated degradation tests highly indicated that TaN films with high crystalline phases, good surface roughness, stable deposition rates, appropriate sheet resistances, and high reliabilities could be obtained if N2 partial pressure was maintained at around 20%. Adhesive strengths of TaN films grown on MLC substrates were increased with increasing substrate temperature up to 300 °C. A low resistance change was confirmed by temperature coefficient of resistance variation as a function of temperature, implying high reliability and durability. Results of this study suggest that TFRs described in this study are suitable for embedded passive resistors with practical applications, including controlled resistances for fabricated TaN based TFRs with different widths.

In magnetron sputtered oxide thin films, both the structure and physical properties are affected by bombardment-induced defects and their annihilation. Ga-doped zinc oxide (GZO) films with low Ga content (~1.7 at.%) were magnetron sputtered at various discharge voltages (70–220 V) and the growth temperatures (130 °C and 380 °C). The microstructure was characterized by X-ray Diffractometry, Raman Spectroscopy, and Transmission Electron Microscopy. Meanwhile, the electrical and optical properties were measured by Hall-effect measurement and Spectroscopic Ellipsometry, respectively. We found that reducing the discharge voltage led to higher structural quality and better electrical properties, independent of the growth temperature. The benefit, from using a high temperature (i.e., 380 °C), of the structural improvement, can only be achieved when the discharge voltage has been decreased to ultralow (i.e., 70 V). Our results suggest that for high quality GZO films deposition, controlling the defect generation should be preferable to simply increasing the growth temperature.

The paper deals with Hf–B–Si–C–N films deposited onto Si and SiC substrates using pulsed magnetron co-sputtering of a single B4C–Hf–Si target (at fixed 15% Hf and 20% Si fractions in the target erosion area) in argon–nitrogen gas mixtures. We focus on the effect of the nitrogen fraction in the gas mixture (in the range from 0% to 50%) and of the voltage pulse length (50 μs and 85 μs with the corresponding duty cycle of 50% and 85%, respectively) on the structure and properties of the films. We show that an increasing nitrogen fraction in the gas mixture and consequently in the films (up to 52 at.%) results in a strong amorphization of the film structure, decrease in the film hardness, and rapid rise in the electrical resistivity and the optical transparency of the films. Very high oxidation resistance in air even up to 1500 °C is demonstrated for two sufficiently hard (20–22 GPa) Hf–B–Si–C–N films: the electrically conductive Hf7B23Si22C6N40 film and the optically transparent Hf6B21Si19C4N47 film, both with a contamination level

Titanium oxide layers were prepared by sputter deposition with plasma emission monitoring in the whole stoichiometry range between Ti and TiO2 without and with substrate heating to 240 °C. The layers were characterized with regard to their crystal structure and specific resistance. Optical constants were determined in the spectral range between 240 nm and 38 μm. The thermochromic behavior of a prepared Ti2O3 layer was measured and compared to calculations for bulk material.

Nickel-containing amorphous carbon (a-C-Ni) films were deposited by magnetron sputtering of graphite and nickel. Graphite magnetron sputtering power was 1500 W. Nickel magnetron sputtering power changed from 0 W to 1000 W, allowing control of the Ni concentration in the films from 0 to 58 at.%. Growth rates of a-C-Ni films were 1.4–2.5 μm/h. High-voltage negative pulsed bias voltage of ‐3 kV amplitude, frequency of 1 kHz, and pulse duration of 50–250 μs was applied to a substrate. The chemical composition of the films was determined using Auger electron spectroscopy. The surface morphology was observed by atomic force microscopy (AFM). The film structure was characterized by Raman spectroscopy and X-ray diffractometry (XRD). The resistivity of the films was measured by a four-point probe method. Film properties that are changed by the added metal, such as structure, electrical resistivity, and hardness, were evaluated and compared with those of pure a-C films as well as with literature values for a-C-Ni films. It is shown that the resistivity of a-C films depends on the duration of the bias voltage pulses and varies from 3.4 to 7.6·10−2 Ohm·cm at pulse duration 50 and 250 μs, respectively. In the case of Ni doping, the a-C-Ni film resistivity can be reduced to 6.7·10−4 Ohm·cm. Where Ni is included in the film in the form of Ni3C carbide, which has hexagonal (hcp) modification, the crystallite size averages 12 nm. The film has a columnar structure and carbon is also present as a graphite-like interlayer 3 nm thick between the Ni3C crystallites. At sputtering power of 600 W of nickel magnetron, a-C-Ni film with resistivity of 5.3·10−3 Ohm·cm is obtained, which can be used as a barrier layer in thermoelements based on bismuth telluride.

In this work, we deal with a study of the electron-transport behavior of zirconium nitride RF magnetron sputtered films using Zr target in reactive nitrogen ambient. The films were grown on silica-coated silicon substrates at a substrate temperature of 300°C. The growth process was monitored using an in-situ spectral ellipsometer in a spectral range from 245 to 1690 nm. The ellipsometric data were analyzed using a dispersion model based on Drude-Lorentz oscillators. We estimated electron-transport properties at each stage of the deposition process by analysis of the model parameters. The mechanism of the thickness-dependent electron-transport phenomenon of the ZrN films is discussed in this work.

BiCuSeO epitaxial films were grown on (001)/(110) SrTtO3 (STO) substrates by RF magnetron sputter deposition. A sputter power over 40 W was needed to transfer target composition to substrate, leading to a fast deposition rate over 17.5 nm/min. The films grown on (001) STO at 100−150 °C showed a dominant [110] orientation instead of [001], which was what expected in view of the smallest lattice misfit and perfect match in symmetry between (001) BiCuSeO and (001) STO. This was caused by slow film growth along c-axis that could not follow the fast deposition rate, whereas a fair lattice misfit, combined with strong bonding along directions vertical to c-axis, entails the growth along [110] at low temperature. Preferred [001] orientation only occurred at high temperature (>350 °C) when the kinetic process was accelerated. However, high temperature and the fast deposition rate imposed by the required sputter power led to the growth of multiple orientations. Epitaxial growth of (001) BiCuSeO film on (001) STO was achieved after the deposition rate was reduced to 0.67 nm/min by a periodically opening and closing shutter installed in front of sputter target. Interestingly, (001) BiCuSeO epitaxial film could be grown on (110) STO at a fast deposition rate of 15 nm/min. Such films on (110) STO had to be grown at higher temperature (∼500 °C). In contrast to (001) STO, (110) STO did not had good lattice match with any BiCuSeO orientation other than [001], so fast kinetic process only promoted the growth of single [001] orientation.

In the present work, manganese ferrite films with the addition of chromium have been produced by reactive pulsed magnetron sputtering of alloyed targets. Layers with thicknesses between 0.5 and 2 μm have been deposited onto flat samples of stainless steel and borosilicate glass. The substrate temperature was in the range from 150 °C to 600 °C, and the oxygen content in the gas atmosphere was set to different values stabilized by a feedback control. Whereas at lower substrate temperatures smooth nanocrystalline films with distinct residual reflectance are formed, at temperatures of 600 °C films with widely varying optical properties and structures arise. Layers with lower oxygen content show a deep black appearance with no transmittance and only minor reflectance. At higher oxygen contents, the transmittance in the red and infrared region strongly increases. In the region of lower oxygen contents, cermet structures with metallic precipitations in a nanocrystalline matrix are formed. At high oxygen content single-phase crystalline layers of spinel type consisting of elongated wedge-shaped crystallites arise. From X-ray diffraction measurement, it was concluded that the metallic precipitations can be assigned to an intermetallic Fe-Cr phase, and the crystalline matrix was of MnFe2O4 spinel type.

This article presents a study of the reactive deposition of coatings by the Pulsed Magnetron Sputtering method with reversely biased electrodes, where the cathode is sputtered at ground potential and an anode, separated from the magnetron body, is positively biased. The reactive sputtering of grounded cathodes occurs by glow discharge plasma localization at the surface of the cathode enhanced by a magnetic field. Our study compares the process of coating deposition running at standard for a magnetron sputtering method with an electrode arrangement which is reversely biased. Processes of coating deposition were carried out in various mixtures of sputtering and reactive oxygen/nitrogen gases. The structure and phase composition of TiO 2 and TiN coatings were examined. In the case of the magnetron system with reversed electrodes biasing we spotted the tendency of nucleation in the rutile phase in the structure of TiO 2 coatings. TiN coatings deposited by this version of magnetron sputtering were characterized by better stoichiometry. We believe that a specific electric field distribution for the magnetron system with a grounded cathode strongly affects the mechanism of synthesis which enhances the reactivity, and thermodynamically stabilizes phases characterized by high barriers of nucleation.

Er-doped TiO2 thin films have been prepared by dual-frequency magnetron co-sputtering with two targets composed of TiO2 and Er2O3. The structural and optical properties of these thin films were investigated using various characterization techniques. X-ray photoelectron spectroscopy measurements show that the content of Er increases when the power on Er2O3 target increases. X-ray diffraction patterns indicate that the anatase TiO2 peaks become weaker with the increasing power on Er2O3 target and the films tend to form amorphous structure. Scanning electron microscopy results show that the grain size decreases with the rise in Er content. UV–vis spectrophotometric analyses reveal that the values of band gap decrease from 3.35 ± 1.3% eV to 3.02 ± 1.3% eV with the increasing amount of Er from 0 at.% to 3.2 at.%. The red shift in the optical adsorption edge may contribute to a higher photocatalytic activity of TiO2 thin films.

International audience; Ta3N5 is a promising candidate for a variety of applications, most notably as a photoactive material for solar water splitting. It is typically synthesized in a two-step process in which oxidized tantalum is annealed in NH3. Magne-tron sputtering is an alternative synthesis method that is little explored to date, as first tries resulted in a small degree of crystallinity of the samples. In this paper, we report on the addition of an axial magnetic field to the conventional magnetron configuration which guides ionic species from the negative glow onto the growing film of Ta3N5. This ion-assisted growth is shown to result in a high degree of crystallinity, i.e. amorphous content, which is typical for conventionally sputtered films, is largely suppressed. The surface of such prepared films is nano-structured by a dense population of grains.

The paper describes a technique for manufacturing of sub-micron metal membranes based on magnetron deposition of multilayer structures. Tensile stress, biaxial elastic modulus and mechanical strength of 25–50 nm thick multilayer Mo/ZrSi2 membranes were measured, and the behavior of these parameters before and after vacuum heating of samples at the level of heat loads up to 1 W/cm2 was studied. The elastic properties were obtained from measurements of deformation dependence of the round membranes on the applied pressure differential. A rapid increase in tensile stress of a 25 nm thick Mo/ZrSi2 film was observed at a uniform heat load of 0.25 W/cm2 which was probably caused by desorption of water molecules from the membrane surface.

Plasma polymers are employed in impressive range of applications due to their unique properties. Although films of plasma polymers are traditionally described as smooth and pinhole free, the possibility to produce nanorough and nanostructured plasma polymerized coatings receives increasing attention. In this study, we tested a fully vacuum-based strategy for production of nanostructured plasma polymers. In the first step of this method, the smooth substrate is seeded by plasma polymer nanoparticles produced by means of a gas aggregation source with a semi-hollow magnetron equipped with a Nylon target. In the second step, the nanoparticles are subjected to fluxes of organic fragments produced by magnetron sputtering of Nylon and such depositions are performed at various angles of incidence. As observed, this enables at higher incidence angles to prepare coatings with well-separated individual plasma polymer nanocolumns.

Magnetron sputtered near equiatomic NiTi thin films were deposited on Si (100) and hot work tool steel substrates. The deposited thin films were in-situ annealed at four different temperatures viz., 80 °C, 305 °C, 425 °C, and 525 °C. The effect of the in-situ annealing temperature on the microstructure of the film, the morphology, as well as mechanical and tribological properties was studied using X-ray diffraction, synchrotron diffraction, transmission electron microscopy, energy dispersive X-ray spectroscopy, ball-on-disc, scratch test, and three dimensional optical microscopy. The obtained results revealed how the variation of in-situ annealing temperature affects the crystallization, microstructure evolution, as well as mechanical and tribological properties of NiTi thin films.

This paper presents the effects of a power pulse delay with regard to a gas pulse generated in the Gas Injection Magnetron Sputtering (GIMS) technique. The GIMS technique is a variant of magnetron sputtering, in which the gas pulses control plasma. During the deposition of a coating, the pressure oscillates between the threshold values, initiating and terminating a discharge. In this work, the power pulse was considered as the second parameter of plasma control over the gas pulse. In our opinion, the state of plasma dynamically changes during the gas pulse period, which was studied using optical emission spectroscopy. The largest population of excited atoms of the sputtering gas was detected in the first stage of the gas pulse, while the highest number of ions was observed in the middle stage and the smallest population of plasma constituents in the end stage. The next step of the study involved examining the structure and phase state of the TiO2 coatings deposited when plasma was generated in various stages of the gas pulse. The structure of the coatings strongly depended on the deposition conditions, such as pressure and plasma content. The coatings were characterized by an amorphous structure that crystallized in rutile form under bombardment by energetic plasma species. The depth of crystallization was influenced by the content of plasma in a particular stage of the gas pulse. During the last stages of the gas pulse, very thick coatings were obtained in the deposition process. Moreover, the coatings exhibited metallic features. In such a condition, it can be expected that there will be no sputtering in reactive gas mixture, and the magnetron might operate in the self-sputtering mode. Thus, this work showed that delaying the power pulse with regard to the gas pulse would help to optimize the features of the deposited coating material.

Lithium doped cuprous oxide ( C u 2 O : L i ) films were deposited on quartz substrates by direct current magnetron reactive co-sputtering of copper and C u : L i targets. X-ray diffraction (XRD), secondary ion mass spectrometry (SIMS), Rutherford backscattering spectrometry, UV-VIS transmittance, and room temperature Hall measurements have been conducted to characterize the deposited films. SIMS revealed Li concentrations in the range 2 × 10 18 − 5 × 10 20 c m − 3 in the doped films. XRD confirms phase pure C u 2 O for all doping concentrations. The doping concentration correlates with an increased free carrier density found from Hall effect measurements. The highest Li doping concentration results in low resistivity ( 4 Ω c m ) p-type C u 2 O with acceptor concentrations up to 2 × 10 17 c m − 3 .

CuO is p-type conductive in nature because of its native point defects, and thus n-type, highly conductive CuO is difficult to obtain due to these native point defects. The introduction of trivalent metallic ions into CuO may deal with the problem. Thus in this work, non-stoichiometric n-type CuO:In3+ thin films are magnetron reactively sputtered at 25 °C (room temperature) and at different reactive pressures (Preact). Compared with CuO thin films, the CuO:In3+ thin films have considerably small electrical resistivity, thereby making CuO:In3+ film a potential candidate of light-absorbing materials in heterojunction solar cells. The high Preact helps improve the crystallization and mobility of the films by the weakened bombardment upon the film surface from the sputtered particles, and by the reduction of the free carrier concentration, respectively. The introduction of In3+ into CuO is more favorable to form n-type and high conduction by partial substitution of Cu by In3+. In addition, a conducting transition from n type to p type is observed at 1.8 Pa Preact. The 1.2 Pa Preact is more suitable for n-type CuO:In3+ for utilization in the photovoltaic application.

In this work, the characterization of high mobility thin-film transistors based on zinc nitride films deposited at room temperature by magnetron radio-frequency sputtering is presented. The values extracted of field-effect mobility were > 2 cm 2 /Vs for long channel devices. For short channel devices, a reduction of the mobility values is found and, as a result of the analysis of the width-normalized resistance for different channel lengths and gate voltages, the reduction is attributed to the effects of a high contact resistance. The impact of the gate dielectric thickness on electrical characteristics is also presented.

Nanolayered metal-ceramic composite systems provide the possibility to produce new materials with exceptional strength, toughness, and radiation resistance not exhibited by their individual constituents. The unusual behaviors are frequently attributed to the high density of internal interfaces. Most layered structures studied to date contain sharp interfaces and the synthesis of more diffuse interfacial structures, where the interface is graded out of the interface plane, has not been deeply explored. Here we show how neutron reflectometry was used to study the structure of magnetron sputter deposited titanium and titanium nitride (Ti/TiN) layers as a function of deposition parameters: temperature, rate of N2 flow or pressure, electrical bias applied to the sample, and orientation of the ion source relative to the sample. These different deposition and post-processing strategies resulted in profound changes in the structure of the interfacial region between the two components in Ti/TiNx bilayers. The results show that temperature and low step-wise N2 flow rates, but not electrical bias, can form graded interfaces in a controlled manner.

International audience; Vanadium oxides are promising candidates for application in memory devices based on the control of their various metal–insulator transitions. We report here on the thin films deposition of the strongly correlated system (V1-xCrx)2O3 over a wide range of composition 0 ≤ x ≤ 0.60 by reactive DC magnetron co-sputtering of pure V and Cr targets. Thin films were characterized by Scanning Electron Microscopy, Energy Dispersive X-ray spectroscopy, X-ray diffraction and transport measurements. These studies demonstrates the existence of compressive stress reaching 0.8 GPa in 200 nm thick films, whereas thicker 1 μm films exhibit lower internal stress. This compressive stress modifies significantly the phase diagram of the 200 nm films, shifting the critical chromium content triggering the bandwidth-controlled metal–insulator transition from x = 0.011 in unstressed films to more than 0.04. This work highlights the need for an accurate control of the Cr content and of the compressive stress to stabilize the Mott insulator phase in (V1-xCrx)2O3 thin films

Ballistic transport model for target-to-substrate atom transfer during magnetron sputter deposition was used to develop zinc target (cathode) configuration that enabled growth of uniform zinc oxide films on extensive surfaces and provided reproducibility of films characteristics irrespective of the cathode wear-out. The advantage of the developed target configuration for high-quality ZnO film deposition was observed in the sputtering pressure range of 5− 50 mTorr, and in the range of cathode-to-substrate distances 7–20 cm. Characteristics of the deposited films were demonstrated by using X-ray diffraction analysis, as well as optical and electrical measurements.

Positional distribution of electrical resistivity and crystalline lattice constant of Ga-doped ZnO films deposited by the magnetron spattering method at room temperature have been investigated. Electrical resistivity and c-axis lattice constant strongly depended on substrate position and substrate–target distance when the films were deposited without substrate heating. Films deposited at the positions facing erosion region showed higher electrical resistivity, less carrier density and elongated c-axis lattice constant than those deposited at the other positions. These films showed exponential-like change of resistivity and carrier density as a function of c-axis lattice constant in a wide range of substrate–target distance. Thermal annealing decreased resistivity and c-axis lattice constant of the as-deposited films and homogenized the positional distribution of their properties. Comparison of electrical and structural changes between before and after the annealing revealed that there are at least three types of defect in the sputtered Ga-doped ZnO films that affect carrier density and mobility with different annealing behaviors.

The electro-mechanical performance of Mo thin films grown by dc magnetron sputter deposition on polyimide substrates was investigated. A series of 500 nm thick Mo films was synthesized at different discharge powers to evaluate the effect of deposition conditions on the structure–stress relationship and to correlate the intrinsic properties of the Mo films with their electro-mechanical response. Different in-situ fragmentation tests were performed to assess the crack morphology, the change in electrical resistance and the film stress during straining. A direct relation between the residual stress state of the Mo thin films and the discharge power was noticed as the stress changed from tensile to compressive with increasing discharge power. All Mo films showed brittle fracture when strained in tension and the critical crack onset strain correlated with the residual stress state. In-situ synchrotron diffraction experiments enabled the characterization of the fracture strength, which was unaltered by the discharge power and found to be approximately 1700 MPa for all Mo thin films studied.

Niobium-doped TiO 2 films as highly transparent conducting oxides for electrical contacts were investigated. As-deposited films were amorphous and exhibited high resistivities ranging from 10 to 10 5 Ω cm. A slight oxygen deficiency in as-deposited films was essential to gain low resistivities (10 − 3 Ω cm) and low optical absorption coefficients ( α 550 nm 3 cm − 1 ) in the annealed films. Therefore, we controlled the oxygen stoichiometry during the film deposition by adjusting the magnetron discharge voltage, while the oxygen gas flow was kept constant. The Hall mobility of degenerately doped films (electron concentration > 10 20 cm − 3 ) increased with decreasing substrate temperature owing to metal-like phonon scattering in these samples.

Structural and magnetic properties of magnetron-sputtered Fe–P(–Mn) thin films with compositions around the Fe2P single phase region are reported, revealing the compositional range of the Fe2P-type structure and the change of the magnetic properties within this composition spread. The structural analysis shows that in order to obtain crystalline Fe–P phases the P content must be higher than (Fe0.97Mn0.03)2.33P. A maximum phase fraction of the Fe2P-type structure is obtained in the examined (Fe0.97Mn0.03)1.78P sample. The hysteresis loops for the Fe2P(–Mn) thin films show a two-step magnetic reversal with one part belonging to an amorphous phase fraction and the other to the Fe2P(–Mn) phase. A maximum coercivity of 0.36 T was measured for the Fe2P(–Mn) phase fraction also at the composition of (Fe0.97Mn0.03)1.78P. Furthermore, electrochemical properties of FeP2(–Mn) thin films as hydrogen evolution catalysts (HER) are studied. FeP2(–Mn) shows a HER onset potential about 200 mV lower than that of Pt. Chronoamperometric testing at − 11.5 mA/cm2 for over 3500 s revealed no obvious decay in current density, suggesting good stability under typical working conditions in a photoelectrochemical device.

One dimensional photonic crystal (1DPC) of TiO 2 /SiO 2 multilayer has been fabricated by sequential asymmetric bipolar pulsed dc magnetron sputtering of TiO 2 and radio frequency magnetron sputtering of SiO 2 to achieve wide omnidirectional photonic band in the visible region. The microstructure and optical response of the TiO 2 /SiO 2 photonic crystal have been characterized by atomic force microscopy, scanning electron microscopy and spectrophotometry respectively. The surface of the photonic crystal is very smooth having surface roughness of 2.6 nm. Reflection and transmission spectra have been measured in the wavelength range 300 to 1000 nm for both transverse electric and transverse magnetic waves. Wide high reflection photonic band gap (∆ λ = 245 nm) in the visible and near infrared regions (592–837 nm) at normal incidence has been achieved. The measured photonic band gap (PBG) is found well matching with the calculated photonic band gap of an infinite 1DPC. The experimentally observed omnidirectional photonic band 592–668 nm (∆ λ = 76 nm) in the visible region with band to mid-band ratio ∆ λ/λ = 12% for reflectivity R > 99% over the incident angle range of 0°–70° is found almost matching with the calculated omnidirectional PBG. The omnidirectional reflection band is found much wider as compared to the values reported in literature so far in the visible region for TiO 2 /SiO 2 periodic photonic crystal.

The surface sintering approach was examined in the present manuscript to obtain single cathode material consisting of multiple elements. Design of electromagnetic discharge without the use of a mechanical press was utilized for this purpose at pulsed pressure oscillations, ranging from 25 to 125 Pa. Meanwhile, each pulsed plasma flux provided absolute energy varying from 87.8 to 279.5 J, resulting in a well-sintered tungsten boride crust within carbon matrix (WBx-C). Its application in sense of sintering degree was estimated by measuring thermal diffusivity, with a maximum value of 3.65 mm2/s achieved at the mid-range neon injection (75–100 Pa). Further, as-surface-sintered cathode material provided suitable contribution to the promising deposition rate (54 nm/min) of W-B-C films by employing gas injection magnetron sputtering in the single magnetron cycle. The quantitative analysis examined using photoelectron X-ray spectroscopy showed that W-B-C films are composed of four elements, of which the W/B ratio was differed prior to prepared cathode materials stoichiometry. The chemical bonding state study revealed the C-W, B-W, B-C and B-O bonds, of which W2BC nanocrystallites (~ 2 nm) were formed in the amorphous structure under the arrangement of neon pulsed glow discharge, and as indicated results of fast Fourier transform and Raman spectra. Nucleation of those ternary nanoclusters promoted a Vickers microhardness result of 26.3 GPa, emphasizing a sensitive response to the mechanical performance of deposited W-B-C films.

Two types of physical vapor deposition Cr coatings were deposited on chemical vapor deposited SiC coupons using conventional direct current magnetron sputtering (DCMS) and high-power impulse magnetron sputtering (HiPIMS) to mitigate the corrosion of SiC, an advanced fuel and structural material in light water nuclear reactor cores. Coating microstructure was characterized using scanning electron microscopy and scanning transmission election microscopy. X-ray diffraction analysis was conducted for phase identification and qualitative analysis of residual stresses. The mechanical integrity of the coatings was evaluated using scratch testing, micro-indentation, and nano-indentation tests. The microstructure of the DCMS coating consisted of fine columnar grains with nanoscale intercolumnar channels, while the HiPIMS microstructure was denser and free of any columnar defects. The DCMS coating showed a small tensile residual stress, while the HiPIMS coating was under compressive stress. Both types of coatings showed good mechanical integrity in terms of ductility and adhesion to the substrate. Corrosion performance of the coatings was assessed with a 30-day high temperature water autoclave test. Both types of coatings formed a protective Cr2O3 surface layer 20-30 nm thick during the autoclave test. In the DCMS coating, the columnar defects provided permeation pathways for water penetration resulting in oxide formation in the intercolumnar regions in the interior of the coating. Overall, both types of Cr coatings offer promise for the mitigation of hydrothermal corrosion of SiC in light water reactor operating environments.

Bi-Sb-Te thin films on SiO2/Si-wafer substrate were prepared by a magnetron co-sputtering process using Bi2Te3 (fixed: 50W) and Sb2Te3 (varied: 10, 15, 20 and 50W) targets. All as-deposited thin films were annealed by rapid thermal annealing (RTA) at 250°C under a vacuum state with a step of heating and holding each for 1 min. The effect of the RTA process onto thin film samples studied concerning the crystal structure, morphology, thickness, composition, and electrical and thermoelectric properties. The crystal structure of annealed samples showed the c-axis preferred orientation with the (00 l) plane (l = 15) and revealed a trend of p-type thermoelectricity behavior due to the RTA process. The annealed thin film compositions were BiTe, Bi0.92Sb0.08Te, Bi0.9Sb0.1Te, Bi0.88Sb0.12Te, and Sb2Te3. The Bi0.9Sb0.1Te thin film composition had the maximum power factor of 4.46 mW m–1 K–2 at a temperature of 100 °C.

Nanoporous copper (NPC) films with ligament sizes ranging from 18 to 46 nm were synthesized by dealloying CuxAl100-x (x = 22–37 atomic percent) precursor films with thickness from 0.5 to 1.2 μm in 0.01–1 M NaOH. The precursor alloy films were deposited on silicon (100) via magnetron co-sputtering. Effects of precursor alloy and dealloying conditions on the morphology of NPC films were investigated by the use of scanning electron microscopy and energy-dispersive X-ray spectroscopy, while the cross-sectional areas were characterized using focused ion beam. The yield strengths of NPC films were measured by the nanoindenter. The morphology of NPC films transformed from well-distributed to aggregated clusters with the increase of Cu concentration from 22 to 37 atomic percent. Limited residual Al and oxidation can be detected in NPC films, regardless of dealloying conditions. The ligament size of NPC films shows no significant difference with the change of NaOH concentrations, while cracks observed in NPC films seem to be mitigated with extended dealloying time. The yield strengths of NPC thin films are higher than those predicted by bulk Cu or pure Cu films.

We report on optical dispersion and temperature dependence of latching-type magneto-optical properties of heavily Ga-doped bismuth iron garnet films rf-magnetron sputtered onto Gd3Ga5O12 (001) and (111) substrates. At λ = 677 nm and room temperature, epitaxial Bi3Fe3.34Ga1.66O12 (001) and (111) films show, respectively, saturation Faraday rotation θFsat = − 0.92 × 104 and − 1.05 × 104 deg/cm, transmittance T = 0.86 and 0.81, magnetic hysteresis θF-H loop squareness θFrem/θFsat = 0.84 and 1.0, and coercive field Hc = 6.76 and 24.03 kA/m. Film's Faraday rotation is nicely fitted by molecular field Neel theory in the whole temperature range from TC = 316 K down to 85 K where θFsat = − 1.9 × 104 deg/cm and Hc = 151.20 kA/m.

A reactive direct current magnetron sputtering method with a controlled total gas flow rate was used to fabricate thin films of tantalum nitride (TaN) on SiO2/Si and multilayer ceramic substrates. In order to identify the total gas flow rate that produced the lowest variation in the sheet resistance and the temperature coefficient of resistance (TCR), TaN films deposited under total gas flow rates of 30, 40, 60, and 80 sccm were characterized in terms of their structural and electrical properties. The optimum total gas flow rate was 60 sccm revealing the lowest deviation of sheet resistance and TCR. Next, the durability and reliability at high temperatures, after heating and cooling cycles, and exposure to induced current were tested. The degradation behaviors and failure of TaN films were investigated by measuring the sheet resistance variation. To further explain the degradation of TaN films, additional analysis of their crystallinity was conducted. The results showed that TaN-based thin film resistors have high durability and reliability and are suitable for embedded passive resistors.

The photovoltaic properties of Cu2O-based heterojunction solar cells were improved using an n-type layer composed of thin films in a binary oxide semiconductor. This layer was prepared by a low-damage deposition method that applies a system for multi-chamber radio frequency (r.f.) power superimposed direct current (d.c.) magnetron sputtering. For an Al-doped ZnO (AZO)/n-ZnO/p-Cu2O heterojunction solar cell prepared using r.f. power superimposed d.c magnetron sputtering, we achieved the highest efficiency yet reported (3.22%) by optimizing sputtering conditions such as the substrate-target distance and the r.f.:d.c. power ratio. This value represents characteristics that exceed those of AZO/Cu2O solar cells having a similar structure based on r.f. power superimposed d.c magnetron sputtering.

Thin layers of ZnO were prepared by using a special modification of the plasma-enhanced chemical vapor deposition known as surfatron. This technique utilizes the principle of surface-wave discharge powered by microwave magnetron generator. Two types of substrate holder regimes (static and movable) were intentionally employed for the preparation of two types of surface morphologies. A series of ZnO films were yielded with thicknesses ranging from 60 nm to 1500 nm. The layers were analyzed by profilometry, scanning electron microscopy, X-ray diffraction, Raman spectroscopy, UV-light adsorption and by a number of electrochemical tests. All prepared samples were crystalline and possessing different surface morphologies. It was shown that the electrochemical response of the films was directly reflecting their surface morphology.

Coatings deposited by magnetron co-sputtering from a single RF magnetron with a ceramic SnO2 target with iron inset in argon plasma were studied. The mass spectra of the process identified Sn+ and SnO+ species as the dominant species sputtered from the target, but no SnO2+ species were detected. The dominant positive ions in argon plasma are Ar+ species. The only detected negative ions were O−. Sputtered neutral tin related species were not detected. Iron related species were also not detected because their concentration is below the detection limit. The concentration of iron dopant in the tin oxide coatings was controlled by the RF bias applied on the substrate holder while the discharge pressure also has some influence. The iron concentration was in the range from 0.9 at.% up to 19 at.% increasing with the substrate bias while the sheet resistivity decreases. The stoichiometry ratio of O/(Sn + Fe) in the coatings increased from 1.7 up to 2 in dependence on the substrate bias from floating bias (− 5 V) up to − 120 V of RF self-bias, respectively. The tin in the coatings was mainly bonded in Sn4 + state and iron was mainly in Fe2 + state when other tin bonding states were detected only in a small amounts. Iron bonding states in contrary to elemental compositions of the coatings were not influenced by the RF bias applied on the substrate. The coatings showed high transparency in the visible spectral range. However, an increased metallic behavior could be detected by using a higher RF bias for the deposition. The X-ray diffraction patterns and electron microscopy pictures made on the coatings confirmed the presence of an amorphous phase.

The effect of substrate temperature on the structure and properties of magnetron sputtered Zr–Cu–Ni–Al–Hf–Ti thin films were systematically investigated. With increasing deposition temperature from 293 K to 493 K, the films remain amorphous but their thermal stability decreases. Crystallization occurs as the substrate temperature reaches 563 K. It was demonstrated that the hardness and Young's modulus of glassy films were enhanced and fracture toughness was worsen by increasing the substrate temperature, along with generating a denser structure. Through the scaling analysis, it was revealed that all glassy films grow in an anomalous mode. These metallic glass films prepared herein exhibit extremely low roughness, less than 1 nm, high thermal stability and excellent mechanical properties, which are useful properties for their potential use for MEMS and other industry applications.

This work investigates the interfacial asymmetry of Fe/Si multilayer films with different thicknesses of Si layer. Four samples of Fe/Si multilayers with monotonically increased Si layer thicknesses were fabricated by using direct current magnetron sputtering technique. Grazing incidence X-ray reflectometry measurement and high resolution transmission electron microscopy were carried out to characterize the inter-diffusion at the interfaces, and selected area electron diffraction technique was utilized to determine the crystalline state of iron layer. The experimental results clearly showed that the thicknesses of Si-on-Fe interfaces were almost constant (~ 0.38 nm), whereas the interface width of Fe-on-Si was decreased from 0.95 nm to 0.38 nm. The interface asymmetry of Fe/Si multilayer transferred from asymmetry to symmetry and the crystallization of iron was suppressed as the Si layer thickness increased to about 24 nm. This result could be explained by the change of local temperature at interfaces as Fe was deposited on Si layers with increasing thickness.

In this study, nanostructured hydroxyapatite (HA) coatings were deposited at a constant power via radio frequency magnetron sputtering. Substrate rotation was applied to increase the uniformity of the thin film properties. The crystallographic orientation, composition and microstructure of the coatings were examined. The characteristics of the deposited coatings associated with the applied deposition conditions were evaluated as a function of time that the samples spent under the target racetrack. The obtained thin films exhibit a change in out-of-plane orientation from preferential (002) to (300) and an increase in the Ca/P molar ratio when exposed for a longer time under the racetrack. This introduces the possibility of tuning crystallographic orientations of HA coatings.

This paper investigates niobia/silica mixed oxide thin films deposited by reactive pulse-DC/RF magnetron co-sputtering of Nb and Si metal targets at room temperature. The reactive gas flow during the sputtering processes was either controlled by direct mass flow rate (i.e. constant reactive gas flow) or by an active feedback process control system. 61% and 137% higher deposition rates of Nb2O5 and SiO2 layers, respectively, were obtained using the latter technique as compared to constant reactive gas flow. Films exhibited bulk or near-bulk density. All mixture films produced in this study had an amorphous structure. A volume law of mixtures was used to determine the coating composition. It is shown that the fraction of SiO2 or/and Nb2O5 has a linear dependency on sputter target power density. On this basis, rugate filter coating designs can be easily deposited, where refractive index gradually varies between that of pure Nb2O5 and pure SiO2. Substantially less inhomogeneity of coating mixtures was found in films produced using a reactive sputtering process with feedback-control.

Amorphous silicon nitride SiNx thin films in a thickness range of 40 to 500 nm were deposited onto (100) silicon wafers using DC magnetron sputtering. The biaxial stress of the films was found to be tuneable in the range of − 1300 MPa (compressive) to almost 0 by varying the plasma power density and the back pressure in the deposition chamber. The films were close to stoichiometric composition with x ranging from 1.27 to 1.34. The refractive index n decreases from 2.10 to 1.97 with increasing back pressure, indicating compositional changes in the thin films. This finding, however, was not confirmed by Fourier-Transform Infrared Spectroscopy measurements. On the other hand, lower wet chemical etch rates revealed a larger robustness of layers deposited at conditions where the mean kinetic energy of the sputtered particles is higher. Temperature dependent leakage current measurements using Au/Cr/SiNx/Si MIS (metal–insulator–semiconductor) structures between 25 and 300 °C have shown that ohmic and Poole–Frenkel conduction mechanisms dominate the leakage current behaviour at electrical fields ranging up to 0.5 MV/cm. The extracted physical parameters such as the corresponding activation energies were found to be mildly affected by the deposition parameters.

There are great interests in electrochromic technology for smart windows and displays over past decades. In this study, the WMoO x thin films were deposited onto indium tin oxide glass and silicon substrates by pulsed magnetron sputter system with W and Mo targets. The films were deposited with fixed W target power while the variant parameter of Mo target power in the range 50, 100, 150 and 200 W was investigated. The working pressure was fixed at 1.33 Pa with a gas mixture of Ar (30 sccm) and O 2 (15 sccm). The film thickness increased with the Mo target power. Higher plasma power resulted in a crystalline structure which would reduce the electrochromic property of the film. The influence of plasma powers applied to Mo target on the structural, optical and electrochromic properties of the WMoO x thin films has been investigated. WMoO x films grown at Mo target powers less than 100 W were found to be amorphous. The films deposited at 150 W, which is the optimal fabrication condition, exhibit better electrochromic properties with high optical modulation, high coloration efficiency and less color memory effect at wavelength 400, 550 and 800 nm. The improvement resulted from the effect of doping Mo has been tested. The maximum ΔT (%) values are 36.6% at 400 nm, 65.6% at 550 nm, and 66.6% at 800 nm for pure WO 3 film. The addition of Mo content in the WMoO x films provides better resistance to the short wavelength light source and can be used in the concerned application.

This study presents an evaluation of copper germanide (Cu-Ge) thin films with low resistivity and high thermal stability. The films were prepared on glass and Si substrates via magnetron co-sputtering deposition and were subsequently annealed at temperatures between 300 and 600 °C. The results indicated that Cu17Ge3 and Cu3Ge phases were formed in films deposited at different sputtering powers using a Cu target and a Ge target. The Cu3Ge phase had a monoclinic structure and reached a low resistivity of 12.4 μΩcm when the film was annealed at 600 °C. This low resistivity in combination with a high-oxidation resistance makes the Cu3Ge film suitable for application in Cu interconnections.

The effects of the CF 4 plasma treatment on resistive memory devices were investigated. First, a 20-nm SiO x film was deposited on a CF 4 -treated W/TiN/SiO 2 /Si substrate using a radio-frequency magnetron sputter, and then a Cu top electrode was deposited to form a Cu/SiO x /CF 4 -treated W structure. The CF 4 plasma treatment deposited fluorine atoms on the tungsten surface, reducing the interface thickness between the SiO x layer and tungsten electrode, and effectively stabilized the resistive switching and improved the switching dispersion. The CF 4 -treated sample showed good memory properties including a reliable non-volatile memory, non-destructive readout, stable switching voltages, and high resistance ratio of 10 5 .

In this study, both gallium-doped zinc oxide (GZO) and indium-added gallium-doped zinc oxide (IGZO) thin films were deposited on commercial glasses by magnetron dc-sputtering in argon atmosphere. The crystal structure, electrical conductivity and optical transmission of as-deposited as well as post-annealed thin films of both GZO and IGZO were investigated for comparison. A small amount of indium introduced into GZO thin films had improved their polycrystalline structure and increased their electrical conductivity by over 29%. All obtained GZO and IGZO thin films have strong [002] crystalline direction, a characteristic orientation of ZnO thin films. Although post-annealed in air at high temperatures up to 500 °C, IGZO thin films still had very low sheet resistance of 6.6 Ω/□. Furthermore, they had very high optical transmission of over 80% in both visible and near-infrared regions.