Sputtering Power Research Articles

The microstructure and mechanical properties of He charged Al films fabricated by HiPIMS/DCMS co-sputtering

Although magnetron sputtering is an effective method to prepare helium (He) charged films, due to the shadowing effect and low plasma density, the films prepared by this method are high porosity and residual stress. In order to solve this problem, the microstructure and properties of He charged aluminum (Al) thin films deposited by the direct current magnetron sputtering (DCMS) and high power impulse magnetron sputtering (HiPIMS)/DCMS co-sputtering were investigated carefully. The results show that, even with the same concentration of He content, He charged film deposited by HiPIMS/DCMS show relatively lower hardness than that of He charged films by DCMS, which the difference is about 0.75 GPa. This is mainly because increased gain size and decreased the number of dislocation loops, due to strong migration ability on the growth surface in HiPIMS/DCMS process. A denser, less columnar structure of He charged film was prepared by the HiPIMS/DCMS co-sputtering, which might help to promote the research on the properties of metal materials containing He bubbles.

Effect of Si content on the microstructure and high temperature oxidation resistance of TiAlCrNiSi high-entropy alloy films synthesized by multi-target magnetron co-sputtering

In this study, we prepared TiAlCrNiSi high-entropy alloy films (HEFs) with different contents of four elements by multi-target magnetron co-sputtering with regulated sputtering power, and the elemental contents of the films all met the high-entropy range (5 at%−35 at%). Scanning electron microscopy (SEM) and atomic force microscopy (AFM) showed that the surface of the films was relatively smooth, the increase of sputtering power and Si element in the films reduced the roughness of the films. This demonstrates the effect of Si in refining the grains and reducing the roughness of the film. X-ray diffraction (XRD) showed that the average grain size of films decreases with the increase of Si content. This phenomenon proves that Si has the effect of refining grains and reducing the roughness of the film. The TC4 substrate and the films were treated at 700 ℃ for 50 h. It was found that TiAlCrNiSi HEFs could improve the high temperature oxidation resistance of TC4. The mechanism of oxidation resistance of the films was investigated by XRD, X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM), and it was found that the generation of dense oxides Al2O3, Cr2O3 and SiO2, the grain refining effect of Si and the appearance of amorphous structure were the main reasons for the increased oxidation resistance.

Hard and Highly Adhesive AlMgB14 Coatings RF Sputtered on Tungsten Carbide and High-Speed Steel

We report a new industrial application of aluminum magnesium boride AlMgB14 (BAM) coatings to enhance the hardness of tungsten carbide ceramic (WC-Co) and high-speed steel tools. BAM films were deposited by RF magnetron sputtering of a single dense stoichiometric ceramic target onto commercial WC-Co turning inserts and R6M5 steel drill bits. High target sputtering power and sufficiently short target-to-substrate distance were found to be critical processing conditions. Very smooth (6.6 nm RMS surface roughness onto Si wafers) and hard AlMgB14 coatings enhance the hardness of WC-Co inserts and high-speed R6M5 steel by a factor of two and three, respectively. Complete coating spallation failure occurred at a scratch adhesion strength of 18 N. High work of adhesion and low friction coefficient, estimated for BAM onto drill bits, was as high as 64 J/m2 and as low as 0.07, respectively, more than twice the surpass characteristics of N-doped diamond-like carbon (DLC) films deposited onto nitride high-speed W6Mo5Cr4V2 steel.

ZnO Deposition on Silicon and Porous Silicon Substrate via Radio Frequency Magnetron Sputtering

Nanostructured Zinc Oxide (ZnO) was deposited on silicon (c-Si) and macroporous silicon (m-PS) using a radio frequency (RF) reactive magnetron sputtering technique. Two RF powers of 60 and 80 W were selected for ZnO deposition on the substrates. Furthermore, the c-Si and m-PS substrate temperatures were kept at 500 and 800 °C, respectively. The morphological, structural, and optical characteristics of the samples were studied using scanning electron microscopy (SEM), an X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), and photoluminescence spectroscopy (PL). The SEM images revealed the formation of ZnO nanorods on the c-Si and ZnO nanostructures constituted by the assembly of nanorods. It has been found that the increasing RF sputtering power caused the rise in the residual stress. In addition, the increase in the deposition temperature caused an improvement in the arrangement of the crystals, which was attributed to the decrease in crystal defects.

Oxygen Vacancies Mediated Co‐Sputtered Ti‐Doped BiVO4Thin Films‐Based Transparent Photovoltaic Device

AbstractBiVO4, a narrow bandgap material (2.5 eV), has been widely explored for photocatalytic applications, but its applications in the optoelectronic field are unexplored. This work explores BiVO4for photovoltaic devices using the oxygen vacancies mediated co‐sputtered Ti‐doped BiVO4(Ti:BiVO4) that exhibits on‐site power production by photovoltaics and see‐through features. The structural, chemical, and optical properties of Ti:BiVO4 are investigated for heterojunction formation with p‐type NiO film. The sputtering power of Ti plays a significant role in improving the light absorption capability by increasing oxygen vacancy concentration, enhancing the device performance. The devices show an open‐circuit voltage value of 676 mV and a short‐circuit current density value of 4.83 mA cm−2with a maximum power production value of 122.2 µW under UV illumination of intensity 53.1 mW cm−2. The obtained device performances correlate with the Ti dopant's deposition power that tunes the structural and optical properties of BiVO4films. Moreover, in self‐powered mode, the fabricated devices show a fast photoresponse speed of 0.8 ms with a high detectivity value of 2.22 × 1012Jones. This work establishes the suitability of co‐sputtered Ti:BiVO4for the next generation of transparent self‐powered optoelectronic devices.

Nonlinear optics properties of Ni-Sb2Se3 nanofilms in the near-infrared region.

S b 2 S e 3 is an emerging material in recent years, and past studies have shown that it has good optoelectronic properties when doped with metals. In this paper, pure S b 2 S e 3 films and N i-S b 2 S e 3 films with different doping contents (1, 2, 3W) were prepared by magnetron sputtering technology. The nonlinear optics properties of the sample films were investigated using femtosecond (fs) Z-scan technology under 800nm. The results showed that both pure S b 2 S e 3 and doped films exhibited reverse saturated absorption (RSA), and the occurrence of the reverse saturated absorption behavior of the doped films was mainly due to two-photon absorption (TPA), free carrier absorption (FCA), and the presence of defective energy levels. Compared with pure S b 2 S e 3 films, N i-S b 2 S e 3 films exhibit significantly enhanced nonlinear absorption properties and nonlinear refractive properties. By increasing Ni sputtering power and incident laser energy, the nonlinear optic properties of N i-S b 2 S e 3 films are enhanced. By testing the sample films using SEM, XRD, and UV-Vis techniques, we found that Ni metal doping greatly improved and optimized the crystallinity of the films and adjusted the optical band gap.

One‐Step DcMS and HiPIMS Sputtered CIGS Films from a Quaternary Target

Using a quaternary compound target, Cu(In,Ga)Se2 films are prepared using one‐step, selenization‐free direct current magneton sputtering (DcMS) and high power impulse magnetron sputtering (HiPIMS) methods. This study investigates how the sputtering power affects the composition, microstructure, morphology, and electrical characteristics of the films. Film crystallinity is found to be affected by the sputtering power utilized. The films deposited at 0.25 kW are amorphous, whereas those formed at 0.5–1 kW display a chalcopyrite structure with a (112)–preferred orientation. With increased sputtering power, the films’ crystal quality improves, displaying a homogeneous and compact morphology free of peeling and cracking. Elemental measurement of the CIGS films reveals that, depending on the deposition method, the film composition deviates from that of the target. The electrical properties of the deposited films vary with increasing sputtering power.

Co-sputtered V2O5–TiN composite on Ag-network current collector for high-performance flexible transparent thin-film supercapacitors

Next-generation wearables require extremely capable electrochemical energy-storage devices that exhibit improved performance with high flexibility and transparency. Herein, we present a highly flexible and transparent electrochemical thin-film supercapacitor electrode fabricated by co-sputtering V2O5 and TiN on an Ag-network-based current collector. The electrodes' physical properties, optical properties, and structural morphologies are studied using X-ray diffraction, UV–visible spectroscopy, and scanning electron microscopy, respectively. A symmetric device is fabricated using V2O5 and TiN on an Ag network, and the TiN sputter power is varied to optimize the performance. The device performance of the co-sputtered electrodes at various composition ratios is studied. The optimized V2O5–TiN (200−40)/Ag electrode device with pseudocapacitive behavior delivers an excellent areal specific capacitance of 98.66 mF cm–2 at a current density of 4 mA cm–2 with a charge retention of 90.12 % after 6000 cycles. The V2O5–TiN (200−40)/Ag electrode device outperforms other reported electrodes, with an energy density and power density of 30.83 μWh cm–2 and 2999.67 μW cm–2, respectively, and excellent mechanical stability.

Emissivity and Optical Properties of Thin‐Film Metallic Glass in the Thermal Infrared Region

AbstractThis study displays the emissivities and optical properties of thin‐film metallic glasses in the thermal infrared (IR) region. It is found that the amorphous structure of the metallic glass hinders the movement of electrons, leading to unique optical properties in the thermal IR region. Measurements of the optical constants of NiNb thin‐film metallic glasses reveal that a high processing pressure and sputtering power yield high optical conductivity and a low damping constant. Adjusting the parameters of the sputtering processes allows the fabrication of thin‐film metallic glasses with a range of damping constants and also the change in the reflectance and emissivity. Applying optical thin film theory, the emissivity of thin‐film metallic glass in the thermal IR region can be modulated. The measured emissivity of the thin‐film metallic glass (45.35%) is significantly enhanced when compared with that of a Si substrate or metal film. Furthermore, the cooling ability of the optimal metallic glass is much higher than that of Si and metal films. These findings reveal that metallic glass films can display thermal radiative properties superior to those of metals and semiconductors, making them promising materials for use in electronic devices with excellent mechanical characteristics and heat dissipation properties.

Effect of magnetron sputtering power on structure and properties of Ta films on Cu substrate of neutron production target for accelerator-based boron neutron capture therapy (AB-BNCT)

Tantalum, with a high hydrogen diffusion coefficient, can be used as an interlayer for neutron production target in Accelerator-based Boron Neutron Capture Therapy (AB-BNCT) to prevent hydrogen embrittlement of Cu substrate. Magnetron sputtering technique was employed to deposit Ta films on the Cu Substrate, with sputtering power being a key parameter. This study investigated the effect of sputtering power on the properties of Ta films deposited on Cu substrate through several methods and Monte Carlo simulations (PHITS and SRIM). A turning point was observed at 250 W, beyond and below which increasing sputtering power led to the increase of Ta film thickness, potentially due to changes in the crystalline structure during deposition. The Ta film exhibited superior surface performance at sputtering powers of 300 W and 350 W. The chemical state of Ta was not affected by sputtering power. Thermal conductivity was observed to decrease after Ta deposition. The thickness of Ta film in this study had a negligible effect on neutron energy spectra and angular distribution. Moreover, a Ta film thickness of 20 μm prevented proton deposition and hydrogen embrittlement in the Cu substrate. These findings have important implications for designing and fabricating neutron production target in AB-BNCT.

Modulation of microstructure and optical properties of anti-reflection HfO2 films by sputtering power and O2/Ar flow ratio

Modulation of microstructure and optical properties of anti-reflection HfO2 films by sputtering power and O2/Ar flow ratio

High-performance broadband photodetectors based on sputtered NiOx/n-Si heterojunction diodes

High-performance broadband photodetectors based on NiOx/n-Si heterojunction were fabricated by radio frequency (rf) sputtering of NiO target at room temperature using 40, 60 and 80 W of power. The open circuit voltage is almost independent of the rf power with value of ∼0.33 V under illumination with red light with optical power of 3.71 mW/cm2, while the short circuit current depends on the sputtering power and has the highest value of 1.3 × 10−7 A (J = 1.45 × 10−3A/cm2) for diodes fabricated at 60 W. The responsivity (R) and specific detectivity in self-powered mode (Vb = 0 V) are higher for the 60 W photodiodes. The R values are 0.39, 0.61, 0.67 and 0.95 A/W under illumination with red, green, blue and UV lights with optical powers of 3.71, 1.03, 1.31 and 0.335 mW/cm2. The On/Off ratio of these diodes at Vb = 0 V is 1.5 × 104, 6.7 × 103, 9.4 × 103, 9.4 × 103 for illumination with the four lights. Capacitance-Voltage measurements indicate high quality of the NiOx/Si interface with low interface defect density and low density of bulk traps in NiOx for diodes obtained at the three powers. The responsivity of the heterojunction diodes obtained at 60 W at Vb = 0 V is among the highest reported in the literature for photodiodes based on NiOx. The quality of the rf sputtered NiOx layers and the low deposition temperature make them attractive for application in flexible optoelectronic devices.

Mechanical Properties and Corrosion Resistance of AlCrNbSiTiN High Entropy Alloy Nitride Coatings

High-entropy alloy (HEA) nitride coatings have been extensively studied due to their desirable properties of high hardness, thermal stability, and corrosion resistance. Among HEA nitride thin films, the AlCrNbSiTiN coatings exhibit very good hardness, high temperature strength, and thermal stability. In this study, six AlCrNbSiTiN HEA coatings with different Al and Cr contents were synthesized using a co-sputtering system with a high-power impulse magnetron sputtering (HiPIMS) power connected to an Al70Cr30 target and a mid-frequency power connected with an Al4Cr2NbSiTi2 high-entropy alloy target. The input power of the Al70Cr30 target was adjusted to obtain AlCrNbSiTiN coatings with different Al and Cr contents. It is observed that the sum of the Al and Cr contents and the (Al + Cr)/(Al + Cr + Nb + Si + Ti) ratio of the AlCrNbSiTiN coatings increased from 59 to 91 at.% when the input power of the Al70Cr30 target increased from 700 W to 1100 W. The single NaCl-type (B1) face-centered cubic (FCC) phase was observed for each coating. The hardness of the coatings increased from 21.2 to 28.2 GPa with increasing Al and Cr contents due to the grain size refinement effect brought by the increasing HiPIMS power. The wear depth and wear rate of the coatings sequentially decreased from 544 to 24 nm and from 2.79 × 10−5 to 2.63 × 10−7 mm3N−1m−1, respectively. Although the adhesion slowly decreased with increasing Al and Cr contents and the hardness of the coating, there was adequate adhesion with a minimum LC3 critical load of 36.1 N. The corrosion resistance of 304 stainless steel in a 3.5 wt.% NaCl aqueous solution was improved by deposition of the AlCrNbSiTiN coating. In this work, the high-entropy AlCrNbSiTiN nitride coating with a (Al + Cr)/(Al + Cr + Nb + Si + Ti) ratio of 91% exhibited excellent surface roughness, the highest hardness of 28.2 GPa, adequate adhesion, and the lowest wear rate of 2.63 × 10−7 mm3N−1m−1 due to its grain refinement effect by the ion bombardment generated with HiPIMS.

Effect of sputtering pressure on the electrochromic properties of flexible NiO films prepared by magnetron sputtering

This study investigates the relationship between the microscopic structure and electrochromic properties of nickel oxide (NiO) thin films and the change in sputtering pressure by depositing NiO films on Polyimide–Indium tin oxide flexible substrates using DC reactive magnetron sputtering. The results demonstrate that the prepared NiO thin films have the best surface morphology and excellent electrochromic properties when the sputtering pressure is 1.0 Pa, sputtering time is 25 min, sputtering power is 125 W, and Ar:O2 ratio is 50:12, with the highest light modulation amplitude of 39.31 %, bleaching and coloring response times of 1.17 and 1.34 s, respectively, and coloring efficiency of 20.05 cm2/C. The findings offer a new method for researching flexible NiO-based electrochromic devices.

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.

Electron-enhanced high power impulse magnetron sputtering with a multilevel high power supply: Application to Ar/Cr plasma discharge

A high-power impulse magnetron sputtering (HiPIMS) power supply, called e-HiPIMS, has been developed and used to deposit chromium thin films within an argon discharge. This power supply comprises three stages; each can deliver a voltage pulse up to 300 V. The advantage of this power supply is the possibility of tailoring a pulse waveform on the cathode with several voltage levels. This e-HiPIMS can operate in the standard HiPIMS mode (s-HiPIMS) and multipulse HiPIMS mode. Each voltage sequence is independently managed regarding the width, delay, and voltage level. They can all be synchronized, giving the s-HiPIMS, or shifted in time and added to each other. Hence, the idea is to favor a specific ion population compared to others, according to the process needs and the targeted application. A beneficial example used a three-pulse sequence with different voltage levels. The influence of the temporal behavior on the plasma parameters, namely, currents and electron energy, has been studied for each pulse sequence. The results show that the discharge current stays within the same order of magnitude as in the standard HiPIMS. The reference current level can be obtained quickly, adding a short over-pulse, even if its voltage level is relatively low. Furthermore, measurements by the Langmuir probe reveal that a maximum electron density is obtained at 0.2 and 0.6 Pa of argon for a configuration that adds two distinguished voltage-pulse sequences, one between 5 and 15 μs and the other between 20 and 40 μs. It comes out that this e-HiPIMS sequence significantly increases the electron density.

The effects of RF power on the optical and electrical properties of transparent conductive Hf-doped In2O3 thin films

Highly transparent conductivity Hf-doped In2O3 (IHFO) films were prepared by RF sputtering on the glass substrate. The effects of sputtering power on the properties of transparent conductive films were studied to optimize the sputtering conditions. X-ray photoelectronic spectra (XPS) showed that the area ratio of OⅠ (oxygen vacancies) to OⅡ (lattice oxygen) achieved the highest value (0.71) at 75 W, resulting in IHFO having the lowest resistivity (2.76 × 10−4 Ω cm). However, the film prepared at 75 W has a low transmittance originating from the intense reflection caused by the high carrier concentration. In comparison, IHFO film deposited at 65 W has a lower resistivity and higher transmittance. Therefore, the IHFO film at 65 W exhibits the maximum figure of merit (FOM) value (7.04 × 10−2 Ω−1) with a low sheet resistance (4.03 Ω/sq) and a favorable average transmittance (88.16%). The p-CuI/n-IHFO diode is exhibited with high transmittance (84.25%) in the visible region and low guiding voltage (0.89 V), implying that IHFO films can be favorably used in the optoelectronic field.

Study on microstructure, optical and tribological properties of self-formed Ta oxide films

Ta2O5 films were deposited on glass and silicon substrates by magnetron sputtering with different power. The microstructure of Ta2O5 films was studied by XRD, SEM, EDS, XPS and AFM. The mechanical and tribological properties of Ta2O5 thin films were studied by ultraviolet–visible spectrophotometer, nanoindentation and friction and wear tester. The sputtering power has a significant effect on the surface morphology of Ta2O5 films. The transmittance of the film decreases with the increase of sputtering power. The optical band gap of the film fluctuates with the change of sputtering power. This is related to the packing density of the sputtered particles and the oxygen vacancies in the film. The wear forms of Ta2O5 films prepared under different sputtering power conditions are mainly fatigue wear and adhesive wear. The optical properties of Ta2O5 films are more sensitive to the change of sputtering power. Ta2O5 films with good optical and tribological properties can be obtained under appropriate process conditions.

Impact of Deposition Power and Gas Flow Ratio on the Tribological Properties of Titanium Vanadium Nitride Thin Films.

Magnetron sputtering was used for producing titanium vanadium nitride (TiVN) coatings on brass substrates. In this research, we investigate how changing the sputtering power and nitrogen:argon (N2:Ar) gas ratio affects the structural and tribological properties of TiVN coatings. A scanning electron microscope (SEM) was used to examine TiVN coating surface morphology. Both variants showed a gradual increase in the intensity of the TiVN coatings' (111) and (222) peaks. The TiVN coatings' tribological properties were examined using a pin-on-disc tribometer with varying loads, speeds, and sliding distances. The wear rates of TiVN-coated brass pins were in the range of 2.5 × 10-4 to 9.14 × 10-4 mm3/Nm depending on load, sliding distance, and gas ratio variation, when compared to the wear rates of TiVN-coated brass pins deposited at various powers, which ranged from 1.76 × 10-3 to 5.87 × 10-3 mm3/Nm.

Influence of Deposition Parameters of ITO Films on the Performance of HJT Solar Cells

TCO (transparent conductive oxide) films are widely used in solar cells due to the characteristics of transparency and conductivity. In this paper, ITO (indium tin oxide) transparent conductive films are prepared on common slides by DC magnetron sputtering, and the preparation process and characteristics of ITO films are studied. The target for sputtering is ITO, with the mass ratio of In203 and Sn02 was 90% : 10%. The sheet resistance, carrier concentration, and carrier mobility of ITO films are measured and analyzed by a UV-Vis spectrophotometer, four-point probe, and Hall effect measurement system. By changing the oxygen content, deposition temperature, and sputtering power to studied the effects on the light transmittance and electrical conductivity of the ITO films, further studied the effects on the HJT (heterojunction with intrinsic thin film) solar cells, and finally determined the appropriate preparation parameters. Results show that the resistance is 6 . 4 ∗ 10 − 4 Ω • cm , the light transmittance is beyond 90.6%, efficiency is 23.78%, and bifacial ratio is 84% when oxygen content is 2.2%, sputtering power is 3 kw, and deposition temperature is 190°C.