Magnetron Sputtering Equipment Research Articles

Influence of design and annealing parameters on measurements of AC properties of NiFe-SiO2 multilayer structures

In this article, due to the exceptionally interesting electrical and magnetic properties of nanocomposites, which include ferromagnetic materials in a dielectric matrix, multilayer NiFe-SiO2 nanocomposites were obtained. The entire sequence of technological processes using magnetron sputtering equipment in the presence of argon was presented, the aim of which was to create structures with different numbers and thicknesses of layers, as well as in two measurement configurations. Measurements of AC electrical properties were carried out in a variable temperature range, i.e. from room temperature to 373 K, using the 4-point method. The obtained measurement results were compared in terms of design parameters, such as thickness and number of layers, as well as technological parameters, such as heating duration. Structural analysis was performed using scanning electron microscopy (SEM) to investigate the effect of oxidation on the multilayer structures and to confirm the granular structure of the nanocomposite. Additionally, the chemical composition of the obtained multilayers was examined using Energy-dispersive X-ray spectroscopy (EDX). Resistive parameters were tested in the range of magnetic field induction from 0 T to 0.3 T. Based on the conductivity relationships, it was proven that a hopping mechanism of current conduction occurs in the tested samples. Using the frequency dependencies of the phase shift angle, it is possible to adjust the equivalent RC electronic circuit, thereby determining the potential application of the tested materials.

Effect of metal seed layer on the critical thickness and photoelectric properties of ultrathin Ag films

To decrease the critical thickness for Ag to form a continuous film and improve the photoelectric properties of the transparent conductive film, the metal seed layer was introduced as a wetting layer, and the metal seed/Ag/AZO composite film was prepared on K9 glass substrates by the magnetron sputtering equipment. The effects of the metal seed layer on both the critical thickness of continuous Ag layer and the photoelectric properties of composite film were investigated. The Al seed layer reduces the critical thickness of the Ag layer to 10 nm, and the square resistance of the Al/Ag (10 nm)/AZO composite film decreases by 5.53 Ω/sq compared to the Ag(10 nm)/AZO bilayer film, while its average transmittance of visible light (380–780 nm) increases by 2.33 %. The Cu seed layer further reduces the critical thickness of the Ag film to 8 nm, and the square resistance of the Cu/Ag(8 nm)/AZO composite film decreases to 9.26 Ω/sq, of which average visible light transmittance reaches 69.34 %. The square resistance of the Cu/Ag (10 nm)/AZO composite film is as low as 7.43 Ω/sq, which is 8.48 Ω/sq lower than that of the Ag (10 nm)/AZO bilayer film.

An integrated ultra-high vacuum cluster for atomic-scale deposition, interface regulation, and characterization of spintronic multilayers

The study of interface spin effects in spintronic multilayer films requires distinguishing the effects generated by different interfaces. However, testing in atmospheric conditions requires a capping layer to protect the films, which introduces new interfaces and limits the study of interface spin-dependent effects. To address this challenge, we have developed an integrated ultra-high vacuum cluster system that includes magnetron sputtering equipment, ion irradiation equipment, and time-resolved magneto-optical Kerr effect (TR-MOKE) equipment. Our sputtering system integrates 12 cathodes in a single chamber, allowing the co-sputtering of four targets. The ultimate vacuum can reach 1 × 10−10 mbar, and the deposition resolution of 0.1 nm can be achieved. Ion irradiation equipment can ionize to produce He+, and by screening and accelerating the implantation of He+ into multilayer films, ion scanning is realized, and up to 30 keV energy can be applied to the films. The TR-MOKE equipment can detect ultra-fast magnetic dynamics processes in vacuum conditions, and its external magnetic field can be rotated 360°. Our vacuum cluster system connects the three subsystems, allowing in situ film deposition, regulation, and characterization. By accurately detecting the effects of different layers, the system can distinguish the interface effects of multilayers. Experimental results demonstrate that the three subsystems can work independently or coordinate to observe the interface effects of multilayers.

Comparative study of titanium carbide films deposited by plasma-enhanced and conventional magnetron sputtering at various methane flow rates

Titanium carbide (TiCx) films were deposited by reactively sputtering Ti target with varied methane (CH4) flow rates using an unbalanced magnetron sputtering equipment operating in conventional (CMS) and plasma-enhanced (PEMS) mode. The microstructure and properties of the TiCx films were mainly scrutinized with X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscopy, nano indentation, and ball-on-disk tribo-test. As the CH4 flow rate is increased from 4 to 16 sccm, x in the TiCx films deposited by PEMS and CMS is gradually increased from 0.28 to 0.96 and 0.28 to 0.73, respectively; and the concentration of TiC phase in the films rises. A densified microstructure with strong preferred growth is observed in the PEMS-deposited films, while a loose columnar microstructure with almost random growth exists in the CMS-deposited films. When the CH4 flow rate is increased, the hardness of the films deposited by PEMS is firstly increased and then decreased, and reaches a maximum value of 29.6 GPa; but that of CMS-TiCx film is fluctuated below 10.6 GPa. The friction coefficient of TiCx-coated samples against pure aluminum is gradually increased with increasing CH4 flow rate from 4 to 14 sccm, accompanied by a reduction of the aluminum adhesion. The wear rate of the TiCx-coated samples as a function of the CH4 flow rate is firstly decreased and then increased. The lowest wear rate of the PEMS-prepared samples is 7.2 × 10−16 m3/(N·m) obtained at a CH4 flow rate of 14 sccm, while that of the CMS-prepared samples is 9.3 × 10−15 m3/(N·m) obtained at 12 sccm. Therefore, PEMS is a promising method to prepare TiCx films with a good combination of the mechanical properties and wear-resistance against pure aluminum.

Investigation of the Properties of Anode Electrodes for Lithium–Ion Batteries Manufactured Using Cu, and Si-Coated Carbon Nanowall Materials

The fabrication of high-capacity, binder-free Li–ion battery anodes using a simple and efficient manufacturing process was reported in this research. The anode material for lithium–ion batteries utilized is a combination of two-dimensional (2D) carbon nanowalls (CNWs) and Cu nanoparticles (improved rate performance and capacity retention) or Si (high capacity) nanoparticles. A methane (CH4) and hydrogen (H2) gas mixture was employed to synthesize CNWs on copper foil through microwave plasma-enhanced chemical vapor deposition (PECVD). The Cu or Si nanoparticles were then deposited on the CNW surface using an RF magnetron sputtering equipment with four-inch targets. To analyze the electrochemical performance of the LIBs, CR2032 coin-type cells were fabricated using anode materials based on CNWs and other components. It was confirmed that the Cu−CNW demonstrates improved rate performance, increased specific capacity, and capacity retention compared with traditional anodes. Additionally, CNW combined with Si nanoparticles has enhanced the capacity of LIB and minimized volume changes during LIB operation.

The impact of dopants (B, H) on the mechanical behavior and tribological performance of DLC film under water lubrication

The tribological behaviors of diamond like carbon films are affected by the surrounding environment. To improve the properties of DLC films, element doping or structural design were carried out. In this work, the B&H co-doped DLC films were successfully deposited on 316 L substrate and Si wafer by closed filed unbalanced magnetron sputtering equipment and studied the effect of H content on the mechanical and tribological properties of the B&H co-doped DLC films. The results indicate that B&H-DLC-2sccm film has the best mechanical performance and adhesive force. Besides, for the friction properties, B&H-DLC-2sccm film has the lowest friction coefficient and wear rate after sliding against Si3N4 ball. This study provides another solution to improve the water lubrication effect of mechanical parts.

Graphene Reinforced Anticorrosion Transparent Conductive Composite Film Based on Ultra-Thin Ag Nanofilm.

Transparent conductive films are widely used in electronic products and industrial fields. Ultra-thin Ag conductive nanofilm (ACF) was prepared on a soda lime silica glass (ordinary architectural glass) substrate with industrial magnetron sputtering equipment with AZO (Al2O3 doped ZnO) as the crystal bed and wetting layer. In order to improve the corrosion resistance and conductivity of the ACF, graphene nanosheets were modified on the surface of the ACF by electrospraying for the first time. The results show that this graphene modification could be carried out continuously on a meter scale. With the modification of the graphene layer, the corrosion rate of graphene-decorated ACF (G/ACF) can be reduced by 74.56%, and after 72 h of salt spray test, the conductivity of ACF samples without modification of graphene can be reduced by 34.1%, while the conductivity of G/ACF samples with modification of graphene can be reduced by only 6.5%. This work proves the potential of graphene modified ACF to prepare robust large-area transparent conductive film.

Microstructural evolution and tribology of Mo-doped diamond like carbon nanocomposite film

To explore the microstructure and tribology property evolution of diamond-like carbon (DLC) film with variable Mo concentrations, Mo-doped DLC films were prepared by magnetron sputtering equipment. The results showed that the Mo concentration in the DLC films increased from 2.1 to 30 at% with the Ar/C2H2 gas flow ratio (3:1–9:1). Mo was dispersed in DLC film at a low doping concentration (2.1 at%). Moreover, MoC nanocrystals were present, and a nanocrystal/amorphous microstructure was formed at a high doping concentration (≥8.3 at%). The DLC films with 2.1 at% Mo showed the best adhesion (200 mN) and the minimum wear rate (1.47 × 10−8 mm3/ N·m), and high Mo concentration (≥8.3 at%) was detrimental to wear resistance and adhesion.

Substrate Surrounding Type Magnetron Sputtering Equipment Comparison of HiPIMS and DCMS Drive

Substrate Surrounding Type Magnetron Sputtering Equipment Comparison of HiPIMS and DCMS Drive

Low temperature quaternary hard coatings with Cr- to Ti-based transition composition

A new quaternary hard coating based on Cr/CrN adhesion layers and a TiCrAlN main coating layer was developed for low-temperature applications. It was deposited in a closed-field unbalanced magnetron sputtering equipment. The nanohardness, adhesion and thickness of the coating were characterized by Anton Paar’s nano-indenter tester, scratch tester and calotester. The chemical composition and surface morphology were investigated by a Hitachi SU 500 scanning electron microscope equipped with an energy dispersion analyzer. The coating showed a low coefficient of friction and a good adhesion strength between the substrate and the Cr/CrN transition layer, as well as between the transition layer and the TiCrAlN layer. The nanohardness achieved was 33 GPa. The research results showed that the quaternary Cr/CrN/TiCrAlN hard coating deposited at 200 °C has mechanical properties comparable to coatings with a similar composition deposited at standard deposition temperatures.

The effect of annealing temperature on Ga2O3 film properties

Using Radio Frequency Magnetron Sputtering (RFMS) equipment, gallium oxide (Ga2O3) films were deposited on sapphire substrates. Then the samples were annealed at 700 °C, 900 °C, and 1100 °C for 120 min in the air atmosphere to convert them into β-Ga2O3 films with different crystalline quality. The effects of annealing temperature on the properties of β-Ga2O3 thin films were investigated. The crystal structure and surface morphology were tested by X-ray Diffraction (XRD), absorption spectroscopy, and Atomic Force Microscopy (AFM). The results obtained show that, within a certain range, as the annealing temperature increases, the intensity of the XRD peaks increases, the Full Width at Half Maximum (FWHW) – decreases. The crystal grains “engorge” as the temperature rises, and the degree of crystallinity of the samples becomes better.

(Invited) Metal Nanoparticles Modified Nitrogen Containing Carbon Film Electrodes for Chemical Sensing

Electrocatalytic performance of metal nanoparticles (NPs) has been studied to apply for electrochemical devices such as fuel cells and electrochemical sensors. We have developed metal NPs embedded carbon film electrodes by co-sputtering of metal and carbon [1]. Various kinds of metals including Pt, Pd, Au, Ni, Cu and their alloys can be fabricated in the carbon film by using unbalanced magnetron (UBM) sputtering and applied for detecting hydrogen peroxide, glucose [1], heavy metals [2,3] and sugar markers [4, 5]. The electrocatalytic activity of metal NPs can be modulated by changing electronegativity of substrate such as carbon electrodes. Here, we proposed Ni NPs electrodeposited on nitrogen containing carbon film electrodes. Method The carbon films were prepared by unbalanced magnetron sputtering equipment and then treated by N2 plasma. The surface of the films were characterized by XPS. Then NiNP was electrodeposited onto both plasma treated and untreated carbon films by changing the deposition potentials. The fabricated electrodes were potential cycled to sufficiently form surface Ni(OH)2 on the surface of NiNPs, then applied for measuring sugar oxidation such as glucose and oligosaccharide in alkaline solutions with different pH. Results and Discussion The nitrogen containing carbon film electrode show unique electrochemical performances including reduction of overpotentials for oxygen reduction and oxidation of some biochemicals such as NADH and L-ascorbic acid [6]. The films also show excellent biocompatibility to suppress the fouling of proteins during electrochemical measurements [7]. When we deposited NiNPs onto the nitrogen containing carbon film, the size of NiNPs became smaller by decreasing potential from -1000 to -1300 mV. Since the size of NiNPs at N2 plasma treated surface is larger than that at pure carbon film, we adjusted the potential to obtain similar NiNPs size on both N2 plasma treated and untreated carbon surfaces. After deposition, both electrodes were potential cycled between 0 and 0.70 V (vs Ag/AgCl) to form surface Ni(OH)2 , which is confirmed by HR-TEM, and HAADF-STEM-EDS images. The redox reaction peaks of Ni(OH)2 oxidation and NiOOH reduction is almost identical when the scan rate is slow (1 mV/s). However, the oxidation and reduction peaks shifted positive and negative directions, respectively at Ni(OH)2 modified untreated carbon film with increasing potential scan rate up to 100 mV/s. In contrast, peak separation increase at Ni(OH)2 modified N2 plasma treated carbon film is greatly suppressed suggesting fast redox reaction similar to at Ni(OH)2. We applied both NiNPs deposited plasma treated and untreated carbon film electrodes for electrocatalytic oxidation of glucose and maltopentaose (G5) in alkaline media. Higher electrocatalytic oxidation currents of glucose was observed at NiNPs on nitrogen containing carbon film compared with those at NiNPs on untreated carbon film particularly in higher glucose concentration region (> 1mM). Moreover, the electrocatalytic current was started to increase sharply at +0.28 V at the Ni@Ni(OH)2-NP/N-C, while that at Ni@Ni(OH)2-NP/C was started to increased gradually at +0.34 V. These results could be due to the slightly formed NiOOH at the low potential region which cannot be detected as current change.And 60 mV potential difference could be interpreted as electrostatic interaction between G5 and electrode surface.In conclusion, the electrocatalytic activity of NiNPs can be enhanced by modifying NiNPs on the N2 plasma treated carbon films, which shows enhanced current and lower onset potential for electrocatalytically oxidation of G5.

Development of Nanocomposite Coating by Hybrid Gas Condensation Process and Magnetron Sputtering Equipment: Electrochemical Characteristics and Surface Analysis

Development of Nanocomposite Coating by Hybrid Gas Condensation Process and Magnetron Sputtering Equipment: Electrochemical Characteristics and Surface Analysis

Design and preparation of FDLC/Ag/FDLC sandwich films with tunable photoelectric performance

Using Film Wizard™ Optical software, we obtained the optimal structural parameters of the thickness of each film layer of DLC/Ag/DLC sandwich structure through computer simulation. Then, FDLC/Ag/FDLC sandwich films with different Ag layer thicknesses were prepared by magnetron sputtering equipment. The surface of the films was dense, smooth, and had uniform particles. The luminous optical transmittance of the FDLC (30 nm)/Ag (16 nm)/FDLC (40 nm) sandwich films in the visible region reached 76.8%. When the thicknesses of the silver layer were 14, 16, and 18 nm, the Figure of Merit of the sandwich films reached 53.6 × 10−3 Ω−1, 66.3 × 10−3 Ω−1, and 52.8 × 10−3 Ω−1, respectively, and all were high values. These values were significantly better than most other previously reported ones for multilayer film electrodes. The optical band gap of the sandwich films was in the range of 1.61–2.54 eV. The band gap was regulated through the thickness of the Ag layer, and the regulation range was approximately 0.93 eV. This finding showed that the FDLC/Ag/FDLC sandwich films can potentially be applied to transparent electrodes and solar cell films.

The improved mechanical and tribological properties of amorphous carbon film by doping boron carbide

Recently, we have reported that graphite-like tribolayers formed on the sliding interface is essential to low friction in nitrogen for amorphous carbon-based (a-C) films with low hydrogen content. Therefore, for hydrogen free a-C film, it is necessary to promote the formation of graphite-like tribolayers for friction reduction. Borides has been proved an effective graphitization catalyst that accelerates the graphitization process of different carbon materials, yet has not been tried for a-C film under friction. Here, we fabricated the a-C and B4C doped a-C (B4C/a-C) films on 304 stainless steel substrates by unbalanced magnetron sputtering equipment. Compared to a-C film, B4C/a-C film exhibited better mechanical properties, as well as superior lubrication performance. Therein, the improved mechanical properties of B4C/a-C film are favorable for the excellent wear resistance. Besides, the friction reduction of B4C/a-C film is attributed to catalytic graphitization of tribolayers formed on the sliding interfaces triggered by B4C. This work indicates that B4C/a-C film will become an alternative solid lubricant material for a wide range of applications in the mechanical engineering fields.

Fabrication, Corrosion, and Mechanical Properties of Magnetron Sputtered Cu-Zr-Al Metallic Glass Thin Film.

The appearance of thin film metallic glasses (TFMGs) is gaining increasing interest because of their unique mechanical and anticorrosion properties and potential engineering applications. In this study, Cu–Zr–Al ternary thin film metallic glasses were fabricated by using DC magnetron sputtering equipment with various target powers. The evolution of the structure was systematically investigated by grazing incidence X-ray diffractometer, scanning electron microscopy, and transmission electron microscopy. The deposition rate increases with the increasing of applied target power. The as-deposited thin films show an amorphous structure. The compositional fluctuations on the nanometer scale indicate the presence of two Cu- and Zr-rich amorphous phases. The electrochemical corrosion measurements indicated that Cu–Zr–Al thin film metallic glasses had good corrosion resistance in the sulfuric acid solution. Nanoindentation results showed that the mechanical deformation was found to be homogenous and reproducible with a high value range for the hardness and modulus.

Effects of short-time plasma treatment in the magnetron sputtering equipment on various carbon nanotubes for applied to LCD backlight unit

The field emission and luminescent properties of various (single-walled CNTs, double-walled CNTs, multi-walled CNTs, and carbon nanofibers) screen-printed carbon nanotubes (SP-CNTs) that were straightened using plasma treatment in the magnetron sputtering equipment (MSE) for a short time were investigated. The SP-CNTs investigated CNT field emitter arrays for back light unit (BLU) in liquid crystal display (LCD). The plasma treatment in the MSE enhanced the emission properties of the single-walled CNTs (SWCNTs) and double-walled CNTs (DWCNTs): the emission uniformity and number of emission sites increased. Recurring problems associated with SW and DW SP-CNTs such as bent and/or buried CNTs and degradation of binder–residue-induced emission were ameliorated by inducing protrusion from the binder and permanent straightening of the SW and DW SP-CNTs as a result of treatment. The multi-walled CNTs (MWCNTs) and carbon nanofibers (CNFs) had partial emission sites with poor emission factors. The results of the present study suggest that plasma treatment in the MSE of SW and DW SP-CNTs is an effective method for achieving uniform field emission and reducing the aging.

Uniform films deposited on convex surfaces by magnetron sputtering with a small target

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.

Effect of Sputtering Current on the Comprehensive Properties of (Ti,Al)N Coating and High-Speed Steel Substrate

To improve the practical property of (Ti,Al)N coating on a high-speed steel (HSS) substrate, a series of sputtering currents were used to obtain several (Ti,Al)N coatings using a magnetron sputtering equipment. The phase structure, morphology, and components of (Ti,Al)N coatings were characterized by x-ray diffraction, scanning electron microscopy, energy-dispersive x-ray spectroscopy, and x-ray photoelectron spectroscopy, respectively. The performance of (Ti,Al)N coatings, adhesion, hardness, and wear resistance was tested using a scratch tester, micro/nanohardness tester, and tribometer, respectively. Based on the structure–property relationships of (Ti,Al)N coatings, the results show that both the Al content and deposition temperature of (Ti,Al)N coatings increased with sputtering current. A high Al content helped to improve the performance of (Ti,Al)N coatings. However, the HSS substrate was softened during the high sputtering current treatment. Therefore, the optimum sputtering current was determined as 2.5 A that effectively increased the hardness and wear resistance of (Ti,Al)N coating.

Surface Analysis of Plasma Pretreated Sapphire Substrate for Aluminum Nitride Buffer Layer

Recently, the use of an aluminum nitride(AlN) buffer layer has been actively studied for fabricating a high quality gallium nitride(GaN) template for high efficiency Light Emitting Diode(LED) production. We confirmed that AlN deposition after N2 plasma treatment of the substrate has a positive influence on GaN epitaxial growth. In this study, N2 plasma treatment was performed on a commercial patterned sapphire substrate by RF magnetron sputtering equipment. GaN was grown by metal organic chemical vapor deposition(MOCVD). The surface treated with N2 plasma was analyzed by x-ray photoelectron spectroscopy(XPS) to determine the binding energy. The XPS results indicated the surface was changed from Al2O3 to AlN and AlON, and we confirmed that the thickness of the pretreated layer was about 1 nm using high resolution transmission electron microscopy(HR-TEM). The AlN buffer layer deposited on the grown pretreated layer had lower crystallinity than the as-treated PSS. Therefore, the surface N2 plasma treatment on PSS resulted in a reduction in the crystallinity of the AlN buffer layer, which can improve the epitaxial growth quality of the GaN template.