Sputtering Parameters Research Articles

Influence behavior and mechanism of crystal orientation of Cu6Sn5 coating on interfacial intermetallic compounds growth in Sn-0.7Cu/Cu solder joint

Herein, the Cu6Sn5 coatings with principal crystal orientations were prepared on the Cu substrate using magnetron sputtering to inhibit the growth of interfacial intermetallic compounds (IMCs) in Sn-0.7Cu/Cu solder joint. The effect of sputtering parameter on the principal crystal orientation of Cu6Sn5 coating was researched firstly, followed by the investigation on the influence of Cu6Sn5 coating principal orientation on the interfacial IMCs growth kinetics. The influence mechanisms were studied using molecular dynamics simulations and first-principles calculations. The results revealed that the increasing sputtering power from 40 W to 60 W and 80 W can not only improve the bonding property between the prepared Cu6Sn5 coating and Cu substrate, but also promote the transformation of the coating principal orientation from (132) to (132)/(22-1) and (132)/(22-1)/(42-2). Moreover, the three prepared Cu6Sn5 coatings can inhibit IMC growth at SC07/Cu solder joint, and the Cu6Sn5 coatings with (132)/(22-1) and (132)/(22-1)/(42-2) principal orientations exhibit more significant inhibitory effects on IMC growth than that with (132) principal orientation. It can be proved in this work that the growth of interfacial IMCs in Sn-0.7Cu/Cu solder joint at aging stage is mainly caused by the diffusion of Cu from Cu substrate toward Cu6Sn5 phase. The difference in the growth behavior of IMCs can be attributed to the fact that when the Cu atoms diffuse across Cu6Sn5 (22-1) and Cu6Sn5 (42-2), the bonding strength between the Cu atom at the saddle point and its surrounding atoms is significantly larger than when diffusing across Cu6Sn5 (132), leading to the smaller diffusion coefficients and a slower interfacial IMCs growth rate.

Study on Process Parameters of Magnetron Sputtering Titanium Coating in Deep Porous Structures.

In order to improve the energy conversion efficiency and power density of the tritium-powered betavoltaic battery, titanium was deposited on the inner surface of the deep porous three-dimensional structure semiconductor as a tritium absorption material. Therefore, magnetron sputtering technology was used to explore the parameters of titanium coating on the inner surface of a deep porous semiconductor. First, the effects of argon pressure and sputtering power on the properties of titanium films were studied. The properties of the titanium films were characterized by a scanning electron microscope and an atomic force microscope. The optimized sputtering parameters were obtained as follows: argon pressure of 0.5 Pa and sputtering power of 80 W. Based on this parameter, the background vacuum and coating angle were changed, and the titanium film was coated in the deep porous structure. Energy dispersive spectrometry line scan and surface scan were used to analyze the coating results, which showed that these two parameters directly affected the content of titanium in the channel, and the area of titanium in the channel structure accounted for more than 50% under each test condition.

Using sputtering parameters to mitigate argon ion sputtering induced reduction of nickel in XPS

Argon ion sputtering for depth profiling in XPS results in the preferential sputtering of oxygen in certain oxide systems. Preferential oxygen removal results in the chemical reduction of the associated cation which is observed in spectra collected following sputtering. Characterizing the effects of different sputtering parameters and developing methods to account for and to minimize changes to chemical states during sputtering would allow for greater confidence in the qualitative and quantitative analysis of the chemical states observed after sputtering. In this study argon ion sputtering was performed with monatomic and clustered argon ions on thermally oxidized NiO. Parameters for monatomic and cluster sputtering were varied to observe their effects on the induced reduction. Results show that extensive reduction is experienced for monatomic sputtering irrespective of the energy and current chosen. For cluster argon ion sputtering, reduction was mitigated when selecting either large cluster sizes or low cluster energies. Sputtering for long periods of time with low energy clusters was observed to result in the removal of surface contaminants without concomitant reduction of the nickel oxide.

Study on Crystallinity and Magnetic Properties of NiCuZn Ferrite Films Deposited by RF Sputtering

Nickel-zinc ferrite proves to be the top-performing material in terms of soft magnetic features for high-frequency applications. The purpose of this study is to explore the impact of various factors such as sputtering pressure, substrate temperature, sputtering power, and sputtering gas, on the magnetic and structural properties of NiCuZn ferrite thin films. In this research, radio-frequency magnetron sputtering of NiCuZn ferrite thin films on silicon substrates was used to investigate the matter. The study demonstrates that reducing sputtering pressure enhances the crystallization of NiCuZn ferrite films and improves their magnetic properties. The saturation magnetization and crystallinity of the thin films initially increased, then decreased as substrate temperature and sputtering power increased. Furthermore, the sputtered films exhibited higher crystallinity and saturation magnetization in a pure Ar atmosphere compared to an oxygen-containing environment. In this study, we optimized the sputtering parameters to achieve a maximum saturation magnetization strength of 253 emu/cc.

Influence of the Gas Flow Rate on the Crack Formation of AlCoCrNi High-Entropy Metallic Film Fabricated Using Magnetron Sputtering

In the present study, the AlCoCrNi high-entropy metallic film was deposited on a Si wafer using a magnetron sputtering system. To capture the effects of the sputtering parameters on the microstructure and mechanical properties of the film, the flow rate of Ar gas injected into the chamber (5, 7, and 8 sccm) was controlled. All films were identified as being of BCC phase with compositions of near equiatomic proportions, regardless of the gas flow rates. Nano-scale clusters were observed on the surfaces of all films, and nano-cracks were found in the film deposited at the Ar gas flow rate of 8 sccm, unlike the films deposited at the gas flow rates of 5 and 7 sccm. Detailed microstructural analysis of film deposition at an Ar gas flow rate of 8 sccm indicated that the void boundaries contribute to the formation of nano-cracks. The nano-indentation results indicated that the Ar gas flow rate 5 sccm specimen, with the smallest cluster size at the topmost surface, showed the highest hardness (12.21 ± 1.05 GPa) and Young’s modulus (188.1 ± 11 GPa) values.

Modulation of electrical properties of sputtered Ta2O5 films by variation of RF power and substrate temperature

Dielectric thin films are important building blocks of microelectronic devices, and hence, research on the development of high-k dielectric thin films has drawn tremendous research interest. In this research, thin films of tantalum oxide (Ta2O5), a high-k dielectric material, are deposited on the Si substrate by the radio frequency (RF) magnetron sputtering technique. During the deposition of Ta2O5 thin film, the sputtering parameters such as sputtering power and substrate temperature were systematically varied, and post-deposition structural, morphological, and electrical properties of sputtered Ta2O5 films are studied by x-ray diffraction, Fourier transform infrared spectroscopy, atomic force microscope, capacitance–voltage (C-V) and current–voltage (I-V) measurement techniques. The annealed Ta2O5 thin film at the temperature of 900 °C for 1 h possesses polycrystalline nature with β—phase orthorhombic crystal structure. The film deposited at 150 W and substrate temperature at room temperature has shown comparatively lower surface roughness, which depicts the energy, and mobility of adatoms greatly influenced by RF power and substrate temperature. With the increase in sputtering power, the oxide charge density (Qox) is found to increase. On the other hand, Qox is found to decrease with the increase in substrate temperature. The film deposited at RF power of 150 W and substrate temperature of 300 °C is found to be of high dielectric constant, low oxide and interface charge density, and lower leakage current.

A strong dependence of sputtering power on c‐axis oriented aluminium nitride on Si (111): A structural and electrical study

AbstractGrowing and controlling the c‐axis orientation of the aluminium nitride (AlN) thin film on unheated Si (111) substrates using reactive magnetron sputtering are challenging. Sputtering parameters such as nitrogen concentration and sputtering power were effectively tuned to grow the c‐axis oriented AlN thin film. The results show that a low concentration of (25%) N2 is enough for forming AlN at a reduced flow rate, whereas a higher flow rate requires a higher concentration of N2. Low concentration with a low flow rate is preferred to grow AlN at low temperature and power. The poor crystallinity of AlN with (100) orientation was improved by varying the power from 75 to 175 W. The X‐ray diffraction results confirmed the improvisation of crystallinity of grown AlN films and indicated the strong dependence of preferred c‐axis orientation on sputtering power. Also, the dependence of sputtering power on microstrain and stress was analysed. The surface morphology study by field emission scanning electron microscopy and topography measured by an atomic force microscope shows a dependence on sputtering power. The high c‐axis orientation was observed at 175 W with low surface roughness, low leakage current density (2 × 10−9 A/cm2) and low dielectric constant (6.8).

Enhanced Hydrogen Evolution Reaction Performance in Alkaline Water Electrolysis: Tuning the 1T Structure of Ni Doped MoS2 Via Co-Sputtering System

Molybdenum disulfide (MoS2) is a promising catalyst for the hydrogen evolution reaction (HER) in alkaline media due to its low cost and abundance. However, its HER activity is not sufficient for practical application because of its electrochemically inert basal plane and suboptimal hydrogen adsorption energy for HER. Herein, we present a facile synthesis approach to fabricate MoS2/Ni HER electrode with 1T structure using co-sputtering of both MoS2 and Ni. Our results indicated that Ni doping plays a critical role in introducing 1T phase in MoS2 structure, leading to an active basal plan, optimized hydrogen adsorption energy, and strong adhesion between the catalyst film and Ni substrate for highly efficient HER performance and durability. We confirmed that the 1T-phase yield, morphologies, and HER activity are affected by sputtering parameters. Our optimized MoS2/Ni electrode exhibited an overpotential of ~91 mV at 10 mAcm-2 and no significant change in HER performance after 1000 cycles operation in 1 m KOH. Single cell test including our optimized electrode exhibited enhanced overpotential and durability compared to a reference cell, highlighting the potential for commercialization in alkaline water electrolysis industry.

Modeling of sputter-based atomic layer deposition with altered parameters

Computational modeling of the sputtering process forming atomic layers of some technologically significant materials was performed based on sputter rate relation. Bismuth atomic layer deposition at different polar angles and ion fluence were shown. The atomic layers getting deposited were studied as a function of incident Argon ion energy at different pressure and a curve analogous to the Bragg curve was obtained. The sputtering parameters were varied to get different atomic layers of TiOx films and the variation of coverage with sticking coefficient was shown. The rate of change of partial sputtering yield with coverage was depicted in the sputter-based deposition of TiN films. The deposition pressure and time were varied to get films of different thicknesses. All the simulated results were correlated with experimental findings with features like variation of reactive gas pressure, electron aided momentum transfer in Bi, multilayer anatase and rutile formation in TiO2 and effect of process parameters on TiN.

Effects of TiO2 thin films on silicon nanowire arrays in heterojunction solar cells

In recent years, the energy crisis has gained increasing attention, with greater emphasis being placed on renewable energy. Currently, solar power is regarded as the most developed form of renewable energy. Many materials have been used in solar cells. Radiofrequency (RF) magnetron sputtering is an effective technique used to produce large-area, easy-to-process thin films. In this study, we fabricated p-layer silicon nanowire (SiNW) arrays by using electroless etching to replace previous multilayer films. TiO2-SiNW array heterojunctions were fabricated by preparing TiO2 as an N layer through magnetron sputtering. Subsequently, the Grey–Taguchi method was used to analyze and optimize p–n heterojunctions with TiO2 films. After the effects of the sputtering parameters (RF power, process pressure, deposition temperature, and deposition time) on surface morphology, material structure, photoelectric conversion efficiency, and reflectivity were investigated, an aluminum-doped zinc oxide (AZO) window layer was added and annealed. Grey correlation analysis revealed a decrease in reflectivity from 8.02225 % to 7.72081 % and an increase in photoelectric conversion efficiency from 0.01915 % to 0.082 %. During the confirmation runs, the TiO2 film was found to be amorphous and wrapped around an array of SiNWs. After the AZO window layer was added, reflectivity increased to 18.04712 %, and the efficiency of photoelectric conversion increased to 0.124 %. In addition, according to the results of the confirmation runs, the AZO film was polymorphic. These experimental results confirm the effectiveness of RF magnetron sputtering, which provides high reflectivity and photoelectric conversion efficiency.

The evolution of preferred orientation and morphology of AlN films under various sputtering parameters

Wurtzite aluminum nitride (AlN) films with (100) and (002) preferred orientations are obtained on Si (100) wafers by radio frequency magnetron sputtering. The effects of target to substrate distance (TSD), RF power, deposition pressure and substrate temperature on crystal orientation and morphology of AlN films are analyzed. It is demonstrated that the TSD is the key factor affecting the preferred orientation of AlN films. The preferred orientation transforms from (002) to (100) with the increase of TSD. Further increase of substrate temperature and RF power causes the coexistence of (002) and (100) orientation. The evolution of orientation is explained by the change in kinetic energy of sputtered particles. The correlation between the crystal orientation and the surface morphology is investigated.

Effects of RF Magnetron Sputtering Power on the Mechanical Behavior of Zr-Cu-Based Metallic Glass Thin Films.

Zirconium-based metallic glass films are promising materials for nanoelectronic and biomedical applications, but their mechanical behavior under different conditions is not well understood. This study investigates the effects of radio frequency (RF) power and test temperature on the nanostructure, morphology, and creep behavior of Zr55Cu30Al10Ni5 metallic glass films prepared by RF magnetron sputtering. The films were characterized by X-ray diffraction and microscopy, and their mechanical properties were measured by a bulge test system. The results show that the films were amorphous and exhibited a transition from noncolumnar to columnar morphology as the RF power increased from 75 W to 125 W. The columnar morphology reduced the creep resistance, Young's modulus, residual stress, and hardness of the films. The creep behavior of the films was also influenced by the test temperature, with higher temperature leading to higher creep strain and lower creep stress. The findings of this study provide insights into the optimization of the sputtering parameters and the design of zirconium-based metallic glass films for various applications.

Efficient CsPbBr3 Quantum-Dot Light-Emitting Diodes Using Sputtered NiO Films as Hole Injection Layers.

Perovskite quantum dots (QDs) have showed excellent optoelectronic properties to extend the application range of novel solid-state lighting, such as perovskite QD based LEDs (QD-LEDs). However, the traditional device structure of perovskite QD-LEDs employed PEDOT:PSS as a hole inject layer (HIL), which impairs stability due to acidic surface characteristics. This study proposes the sputtered NiO films as an HIL to replace acidic PEDOT:PSS. The NiO films with significantly different characteristics were prepared by controlling the sputtering parameters to investigate the devices' performance of NiO-based CsPbBr3 QD-LEDs. The optimized device showed an excellent performance with maxima luminescence of 20,118 cd/m2 and an external quantum efficiency (EQE) up to 3.63%.

Hydrophobic, anticorrosion, and frictional properties of F-DLC films prepared by magnetron sputtering

Fluorine-doped diamond-like films (F–DLC) were prepared through the RF magnetron sputtering technique, and the effects of different F contents on their components, structure, and properties were investigated. Doping with F was found to induce a transition from the sp3C phase of the three-dimensional spatial structure to the sp2C phase of the two-dimensional polymer structure in the DLC films, generating a C–Fx bonding group. The use of reasonable sputtering parameters to regulate film components and structure yielded films with excellent hydrophobicity and corrosion resistance. The water contact angle, corrosion current density, and coefficient of friction of the films were 101.2°, 3.0207 × 10−8 A∙cm−2, and 0.08, respectively. Further analysis revealed that the excellent hydrophobicity and corrosion resistance of the films were mainly due to the surface roughness of the films, together with the increase in two-dimensional polymer and C–Fx (x = 1,2,3) bonding structures within the films. The films had a low coefficient of friction that was attributable to their reduced C–C bond content, C–Fx bond replacement in the σ-suspension cement that was suspended during film friction, and the graphite-like transfer film generated during friction.

Optimization of Growth Parameters of the RF-Sputtered CuInGaSe2 Thin Films for Photovoltaic Applications

CuInGaSe2 (CIGS) thin films were deposited by RF sputtering using a single quaternary target. The effects of various sputtering parameters, such as substrate temperature, sputtering power, and gas flow rate, were studied systematically. The structural, morphological, compositional, and optical properties of the films were investigated by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDAX), and UV–vis-NIR spectroscopy. The samples exhibited the chalcopyrite type tetragonal structure of CIGS, as confirmed by the XRD analysis. Raman spectroscopy represents the presence of Cu poor ordered vacancy compound (OVC) phase in all the present samples. The growth of the sample at a higher substrate temperature resulted in a higher crystalline nature with a suppressed OVC phase and energy bandgap of 1.18 eV. The deposition of CIGS at 160 W sputtering power favors growth towards (112) Bragg crystal plane, suppressing the (220)/(204) plane of CIGS, shows change in preferred orientation with a lower sputtering power at 80 and 120 W. The sample grown at a gas flow rate of 60 standard cubic centimeters per minute (SCCM) exhibited compact grain growth with marginally improved crystallinity. The sample grown at 160 W, 300 °C, and 60 SCCM showed better crystalline and morphological properties, and it can be used as an absorber layer for highly efficient CIGS thin-film solar cells.

Controlling the shape of hexagonal structure by growth condition improves the thermoelectric properties of p-type Bi-Te films

Improving the thermoelectric (TE) properties of typical p-type Bi0.5Sb1.5Te3 film is crucial for power generation in film-based thermoelectric devices. The shape of the hexagonal structure in the Bi0.5Sb1.5Te3 film can be controlled by adjusting the magnetron sputtering parameters. The results indicate that a high nucleation rate under high sputtering power promotes island growth with a preferred orientation of (015). Thermal energy influences the growth in the in-plane direction along the (00 l) orientation and induces the c-axis orientation in the out-of-plane direction. Consequently, a dense layered hexagonal structure with a high grain boundary density is formed, leading to increased defect density, carrier concentration, and phonon scattering. In this case, the power factor reaches 3149.01 μW·m-1·K-2 at 480 K and the ZT value is 1.14 at 480 K. These results indicate that the film with a dense layered hexagonal structure enhances the TE properties.

Optimizing the growth conditions of Al mirrors for superconducting nanowire single-photon detectors

We investigate the growth conditions for thin ( nm) sputtered aluminum films. These coatings are needed for various applications, e.g. for advanced manufacturing processes in the aerospace industry or for nanostructures for quantum devices. Obtaining high-quality films, with low roughness, requires precise optimization of the deposition process. To this end, we tune various sputtering parameters such as the deposition rate, temperature and power, which enables 50 nm thin films with a root mean square roughness of less than 1 nm and high reflectivity. Finally, we confirm the high-quality of the deposited films by realizing superconducting single-photon detectors integrated into multi-layer heterostructures consisting of an aluminum mirror and a silicon dioxide dielectric spacer. We achieve an improvement in detection efficiency at 780 nm from 40% to 70% by this integration approach.

Electrospun Poly-L-Lactic Acid Scaffolds Surface-Modified via Reactive Magnetron Sputtering Using Different Mixing Ratios of Nitrogen and Xenon.

Controlled regeneration processes involving tissue growth using the surface and structure of scaffolds, are actively used in tissue engineering. Reactive magnetron sputtering is a versatile surface modification method of both metal and polymer substrates, as the properties of the formed coatings can be modified in a wide range by changing the process parameters. In magnetron sputtering, the working gas and its composition have an influence on the chemical composition and physical characteristics of the obtained coatings. However, there are no studies addressing the influence of the nitrogen/xenon gas mixture ratio in direct current magnetron sputtering on the deposition rate, physicochemical and in vitro properties of surface-modified biocompatible poly-L-lactic acid scaffolds. In this study, the application of mixtures of nitrogen and xenon in various ratios is demonstrated to modify the surface of non-woven poly-L-lactic acid scaffolds by direct current magnetron sputtering of a titanium target. It has been found that the magnetron sputtering parameters chosen do not negatively influence the morphology of the prepared scaffolds, but increase the hydrophilicity. Moreover, quantitative spectroscopic analysis results indicate that the formed coatings are primarily composed of titanium oxide and titanium oxynitride compounds and is dependent on the gas mixture ratio only to a certain extent. Atomic force microscopy investigations of the roughness of the fibers of the electrospun scaffolds and the thickness of the coatings formed on them show that the considerable variations observed in the intrinsic fiber reliefs are due to the formation of a fine layer on the fiber surfaces. The observed decrease in roughness after plasma modification is due to temperature and radiation effects of the plasma. In vitro experiments with human osteosarcoma cells show that the scaffolds investigated here have no cytotoxic effect on these cells. The cells adhere and proliferate well on each of the surface-modified electrospun scaffolds, with stimulation of cell differentiation in the osteogenic direction.

Effect of deposition angle on the deposition rate, microstructure, electrical and optical properties of magnetron sputtered ZrB2 thin films

The microstructure and properties of thin films prepared by magnetron sputtering are usually sensitive to not only sputtering power and working pressure, but also the incident direction. In this work, ZrB2 thin films were prepared by DC magnetron sputtering at same sputtering parameters but substrate inclined from 0° to 30°. The deposition rate, microstructure, electrical and optical properties were investigated in details. XPS analysis demonstrates that all the prepared ZrB2 films are B-rich in compositions. Microstructure characterization shows the ZrB2 films deposited at bigger oblique angles are with better crystallization and bigger surface roughness, the former leads to the films with lower resistivity, the latter leads to the films with stronger absorbing ability in the UV–vis-NIR wavelength band. Adjusting substrate to a suitable oblique angle is a promising method to achieve higher quality ZrB2 films..

Optimization of RF sputtering parameters for improving the optical and electrical properties of β-gallium oxide thin films

Optimization of RF sputtering parameters for improving the optical and electrical properties of β-gallium oxide thin films