Plasma Emission Monitoring Research Articles

Fabrication of TiN coatings using superimposed HiPIMS and MF technique: Effect of target poisoning ratios and MF/HiPIMS pulse on-time ratio

The commercial application of high power impulse magnetron sputtering (HiPIMS) is hindered by its low deposition rate in thin film and coating industries. This study proposes an effective method to enhance the deposition rate of TiN films by superimposing middle-frequency (MF) pulses during the off-time of HiPIMS pulsing. The impact of Ti target poisoning ratios (ranging from 30 % to 70 %) controlled by the plasma emission monitoring (PEM) feedback control system and MF/HiPIMS pulse on-time ratios (ranging from 1.5 to 24) on the structural, morphological, and mechanical properties of thin films was investigated. Increasing the target poisoning ratio and the ratio of MF/HiPIMS on-time pulses up to 6 resulted in increased peak current and peak power density of HiPIMS for the superimposed TiN films. Compared to TiN films grown solely using HiPIMS, all the superimposed TiN films exhibited improved deposition rates ranging from 3.89 to 6.36 nm/kW·min. Analysis of crystallographic and chemical composition confirmed the formation of single-phase stoichiometric TiN films with a smooth columnar microstructure. The TiN film grown at a 60 % target poisoning ratio and an MF/HiPIMS pulse on-time ratio of 1.5 displayed the highest hardness of 34.4 GPa and elastic modulus of 485 GPa, surpassing the values obtained for pure HiPIMS-grown, MF-grown, and DC-grown films. Moreover, TiN film deposited at target poisoning ratios of 50 % and a 6 times MF/HiPIMS pulse on-time ratio exhibited a high hardness of 30.3 GPa and a high deposition rate of 5.94 nm/min/kW, which was 2.15 times higher than that of pure HiPIMS. Additionally, the formation of stoichiometric TiN films led to relatively lower electrical resistivity. Overall, the superimposition of HiPIMS and MF pulses presents a promising approach to overcome the limitations of HiPIMS and enhance the deposition rate of TiN films. The findings of this study highlight the potential of TiN films grown by the superimposed HiPIMS-MF and PEM feedback control technique for various industrial applications.

The influence of different power supply modes on the microstructure, mechanical, and corrosion properties of nc-TiC/a-C:H nanocomposite coatings

Titanium carbide (TiC) coatings have attracted wide attention from researchers and industry due to their high hardness, wear and corrosion resistance . In this study, a plasma emission monitoring system was adopted to feedback control the target poisoning status of 70% in a gas mixture of acetylene using four different power supply modes including superimposed HiPIMS-MF, HiPIMS , MF, and DC. The nanocrystalline TiC/a-C:H nanocomposite coatings containing NaCl-type TiC nanocrystallites (3–7 nm in diameter) embedded in a hydrogenated amorphous carbon (a-C:H) matrix microstructures were fabricated by four different power supply modes. The corrosion resistance of 304 stainless steel substrate against the sulfuric acid attack was greatly improved by the four nc-TiC/a-C:H nanocomposite coatings. Although the deposition rate of the coating prepared by the DC power supply was the highest, the film quality was inferior to other films due to its higher oxygen content and larger TiC grain size . On the other hand, the nc-TiC/a-C:H coating fabricated by the superimposed HiPIMS-MF power mode exhibited a featureless microstructure with the highest hardness of 27.5 GPa and the highest H 3 /E 2 ratio of 0.38. The nc-TiC/a-C:H nanocomposite film grown by superimposed HiPIMS-MF became a promising protective coating in severe environment applications due to its high hardness, good adhesion, adequate tribological properties, and excellent corrosion resistance against sulfuric acid. • Four different power supply modes are used to grow four nc-TiC/a-C:H coatings. • A plasma emission monitoring system is utilized to control reactive C 2 H 2 gas. • The coating consists of TiC nanograins embedded in an amorphous C matrix. • Superimposed HiPIMS-MF yields a coating with the highest hardness of 27.3 GPa.

Effect of target poisoning ratios on the fabrication of titanium oxide coatings using superimposed high power impulse and medium frequency magnetron sputtering

Five titanium oxide coatings with different O/Ti ratios were grown by a superimposed high power impulse magnetron sputtering (HiPIMS) and medium frequency (MF) coating system utilizing a plasma emission monitoring feedback control. The peak power density of HiPIMS increased from 517.6 to 658.5 W/cm2 and the O/Ti ratio increased from 1.4 to 2.3 as the target poisoning ratio increased from 10% to 90%, whereas the deposition rate decreased with increasing target poisoning ratios. A pure TiO phase gradually transferred to a mixture phase of anatase and rutile TiO2 as the target poisoning ratio increased. The amount of anatase TiO2 increased with increasing target poisoning ratios and reached almost a pure anatase phase as the target poisoning ratio was 90%. The highest hardness of 16.4 GPa and the best corrosion resistance were found for the coating with pure TiO phase grown at 10% target poisoning ratio (TB10). The hardness decreased gradually as the structure changed from a pure TiO phase to the rutile and anatase mixed phases. A low hardness of 5.8 GPa and a poor corrosion resistance were obtained for the anatase rich TB90 due to its microstructure defects. Good adhesion and wear resistance were achieved for coatings deposited at 70% and 90% target poisoning ratios (TB70, TB90). Among these five coatings, TB70 coating exhibited a hardness of 12.6 GPa, good wear resistance, adequate adhesion, and fair corrosion resistance, which can be used as a functional coating with good protection property.

Effect of Cr Atom Plasma Emission Intensity on the Characteristics of Cr-DLC Films Deposited by Pulsed-DC Magnetron Sputtering

A pulsed-dc (direct current) magnetron sputtering with a plasma emission monitor (PEM) system was applied to synthesize Cr-containing hydrogenated amorphous diamond-like carbon (Cr-DLC) films using a large-size industrial Cr target. The plasma emission intensity of a Cr atom at 358 nm wavelength was characterized by optical emission spectrometer (OES). C2H2 gas flow rate was precisely adjusted to obtain a stable plasma emission intensity. The relationships between Cr atom plasma emission intensity and the element concentration, cross-sectional morphology, deposition rate, microstructure, mechanical properties, and tribological properties of Cr-DLC films were investigated. Scanning electron microscope and Raman spectra were employed to analyze the chemical composition and microstructure, respectively. The mechanical and tribological behaviors were characterized and analyzed by using the nano-indentation, scratch test instrument, and ball-on-disk reciprocating friction/wear tester. The results indicate that the PEM system was successfully used in magnetron sputtering for a more stable Cr-DLC deposition process.

Thermochromic Properties of Vanadium Oxide Films Prepared by R-HIPIMS Using Closed-Loop Controlled with Plasma Emission Monitoring

The vanadium dioxide films were deposited by reactive high-power impulse magnetron sputtering for different plasma emission intensity at the substrate temperature of 310 °C. The setpoint of plasma emission intensity was controlled by a PID controller with plasma-emission-monitoring. The vanadium dioxide films characteristics were measured by optical spectrophotometer, X-ray diffraction and electrical source meter.

Synthesis of iron oxide films by reactive magnetron sputtering assisted by plasma emission monitoring

• FeO films were synthesized by pulsed-DC magnetron sputtering from metallic target. • The film oxidation was controlled with a plasma emission monitoring system. • Special attention was paid to the sample position relative to the target axis. • Structural features depend on the oxidation rate of the growing films. • FeO behaviors are tuned from hematite semiconductor to magnetite semimetal properties. A R T I C L E I N F O Keywords: FeO Reactive sputtering Plasma emission monitoring Hematite Magnetite A B S T R A C T Iron oxide films were synthesized by pulsed-DC magnetron sputtering from a metallic target in Ar and O 2 gas mixtures. Plasma emission monitoring was implemented to accurately control the metal-to-oxygen ratio in the coating through the chemical state of the iron target. The intensity of the Fe* emission line was maintained at a given value (setpoint) by regulating the introduced oxygen flow rate. In addition, the oxidation rate of the growing film was adjusted by controlling the oxidation-to-deposition rate ratio as a function of the position of the substrates relative to the magnetron axis. The iron oxide films were characterized by X-ray diffraction, UV-VIS spectrophotometry, electrical measurement and vibrating sample magnetometry. In addition to the crys-tallization of pure hematite and magnetite phases, both phases coexist in a transition domain for a short range of setpoint depending on the oxidation-to-deposition rate ratio. The electrical, optical and magnetic behaviors of the FeO x films suggest that the relative proportion of phases can be tailored in this range. The FeO x film behaviors can then be tuned from the hematite semiconductor properties to the semi-metallic magnetite properties .

High rate reactive sputtering of Al2O3 coatings by HiPIMS

High rate reactive sputtering of insulating metal oxide coatings, e.g. alumina (Al2O3), by high power impulse magnetron sputtering (HiPIMS) is of strong interests, as the increased ionization of target species in a HiPIMS process can be used to improve the structure and properties of the coatings. The challenges for reactive sputtering of Al2O3 using HiPIMS include arc suppression on the target surface and low deposition rates due to target poisoning. In this study, AlxOy coatings were reactive sputtered by deep oscillation magnetron sputtering (DOMS), one version of HiPIMS, which generates large oscillatory micro-pulses within long modulation pulses. The process stability was evaluated by measuring micro arc counts on the target at different combinations of on and off times of the oscillatory micro-pulses. Virtually arc-free depositions for Al2O3 were observed by utilizing combinations of short oscillation micro-pulse on time (<4 μs) and longer oscillation micro-pulse off time (>40 μs) at a peak target current of 130 A. The mechanisms of generating arc-free discharge for insulating coating reactive sputtering using deep oscillatory micro-pulses are discussed. The hysteresis behavior with open-loop for reactive sputtering of AlxOy using DOMS was studied. The closed-loop control for reactive sputtering was achieved by controlling the oxygen partial pressure (PO2) using the feedback signal from a remote penning plasma emission monitoring sensor, which generates an ionized sample plasma away from the deposition zone. The deposition rate, microstructure, and mechanical and optical properties of the AlxOy coatings deposited at different PO2 in the transition region were investigated. Up to 56% of the metallic deposition rate has been achieved for obtaining stoichiometric Al2O3 coatings by controlling the PO2 around 0.0143 Pa. The DOMS Al2O3 coatings show improved mechanical properties and optical transmission as compared to those obtained by pulsed dc magnetron sputtering reported in the literature.

Comparison of chromium carbide thin films grown by different power supply systems

The potential use of chromium carbide thin films has been a great interest to academia and industry due to their outstanding properties such as chemical stability, low coefficient of friction, adequate hardness and high wear resistance. In this study, the chromium carbide thin films were fabricated by a magnetron sputtering using different power supply systems, including direct-current (DC), pure high power impulse magnetron sputtering (HiPIMS), and superimposed HiPIMS- middle frequency (MF). The Cr target poisoning status was controlled using a plasma emission monitoring (PEM) system by adjusting the gas flow ratios of Ar and acetylene (C2H2). The morphology and microstructure of thin films were evaluated by scanning electron microscope (SEM) and transmission electron microscope (TEM). The crystallinity of films was studied using an X-ray diffractometer (XRD). The electron probe micro analyzer (EPMA) and X-ray photoelectron spectroscope were used to determine the chemical compositions and binding structures of thin films, respectively. The hardness and residual stress were explored. The results showed that the thin film sample prepared by the superimposed HiPIMS-MF power supply can obtain the maximum hardness of ~27.5 GPa at a PEM set point of 30%, i.e., the target poisoning degree of 70%. The hardening mechanism may be caused by the formation of nanoscale CrC crystallites incorporated into the amorphous CrCx matrix in the thin film, which can be attributed to the Hall-Petch strengthening effect.

NiO-GDC10/GDC10/LSCF-GDC10 Manufactured By Tape Casting and Reactive Magnetron Sputtering Processes of Solid Oxide Fuel Cells

We developed a cost–effective a method to manufacture performance planar solid oxide fuel cells using composite electrode by tape casting and electrolyte by reactive magnetron sputtering. NiO and GDC (10% Gd), used for the anode-supported (as) and the anode functional layer (afl) powders were milled by using zirconia balls in a Turbula-(System Schatz from WAB) times up to 24 hours. Half-cell, 28 mm of diameter, Ni-GDC composite anodes have been fabricated by slurry based tape casting (Elcometer4340 Automatic Film Applicator) method for anode supported solid oxide fuel cell. Depending on the results, work on the support anode (AS) Ni0-GDC will continue in particular to avoid the presence of the residual phase of carbon resulting from the use of an agent poro formers with graphite . The decomposition of organic additives and the shrinkage of green tape is analyzed thermo-gravimetric and differential thermal analysis (TG) of anode. PVD by plasma emission monitoring (PEM) was employed to synthesize GDC (10%Gd doped ceria) thin films on anode-grade ceramic substrate (porous NiO-GDC10). An Alcatel SCM650 sputtering chamber was used for synthesizing the dense GDC layers. A Ce-Gd metallic target (90-10% at) was powered by a pinnacle + pulsed current generator from Advanced Energy under reactive atmosphere.The cathode, which is made of (LSCF-GDC10) was screen printed onto electrolyte film and sintered to form a complete SOFC. The obtained cell after sintering was seen without any deformation or crack. Pycnometry and porosimetry techniques were primarily used to determine pore size and pore volume by equation Washburn and Ideal gas law-method and the decomposition of organic additives and the shrinkage of green tape was analyzed thermo-gravimetric of NiO-GDC10 and LSCF-GDC10. The microstructural morphological surface features of the cell was by 3D profilometry and complete cell were analyzed by Scanning Electron Microscopy (SEM), XRD and was employed to nos-destructively quantify the craking and behavior observed before and after different annealing. The measurements will be carried out on a complete cell with the measuring bench of the company Fiaxell of 5*5 cm2 and on a cell of 28 mm of diameter in order to obtain curves I / V.

Mechanical property evaluation of ZrSiN films deposited by a hybrid superimposed high power impulse- medium frequency sputtering and RF sputtering system

The high power impulse magnetron sputtering (HiPIMS) technique has been studied intensively due to its high peak power density and high ionization rate. The drawback, low deposition rate, of the HiPIMS can be improved by superimposing the middle-frequency (MF) pulses during the off-time of HiPIMS pulsing. In this study, a hybrid coating system consisting of a radio frequency power supply and a superimposed HiPIMS-MF sputtering system was used to deposit the ZrN and ZrSiN coatings with different Si contents ranging from 0 to 11.5 at.%. The Zr target surface status was maintained at the transition mode by a plasma emission monitoring system for keeping high deposition rate. The microstructure of ZrSiN film changed from a fine columnar to a featureless structure when the Si content was higher than 4.7 at.%. The maximum hardness of 33.4 GPa was obtained for the film containing 4.7 at.% Si due to the solid solution hardening and grain refinement strengthening effects. The film hardness further decreased to 20.9 GPa as the Si concentration increased to 11.5 at.%, which can be attributed to the formation of large amount of soft amorphous SiNx phase. On the other hand, the corrosion resistance of ZrSiN film increased with increasing Si content due to the effective reduction of grain size, lower surface roughness, and further densification of microstructure by amorphous SiNx phase. The corrosion resistance of AISI304 stainless steel substrate can be effectively improved to 8 to 15 times better by the ZrSiN coating. The 4.7 at.% Si contained ZrSiN coating had the highest hardness, good adhesion and corrosion resistance in this work.

Superimposition of high power impulse and middle frequency magnetron sputtering for fabrication of CrTiBN multicomponent hard coatings

The combination of superimposition and hybrid target powers using a superimposed high power impulse magnetron sputtering (HiPIMS) power and middle-frequency (MF) power system, together with the hybrid of direct-current (DC) and radio-frequency (RF) powers was adopted in this work to grow CrTiBN hard coatings. The flexibility of tailoring the chemical composition, phase, deposition rate, microstructure and mechanical properties of CrTiBN coatings through the feedback control of reactive N2 gas flow rate and the corresponding Ti target poisoning status by a plasma emission monitoring (PEM) system was successfully illustrated in this work. Both the peak current and peak power density of Ti target increased with increasing poisoning ratio, i.e., decreasing PEM set point. The 1.64 times higher deposition rate of CrTiBN films can be obtained when the Ti target status changes from poisoning (PEM set point 30%) to transition regime (PEM set point 70%). Fine and compact film microstructure, and a very smooth surface are fabricated for all films. Each coating shows a low coefficient of friction and low wear rate ranging from 0.46 to 0.49 and from 2.06 to 5.73 × 10−6 mm3 N−1m−1, respectively. The highest hardness of 34.1 GPa, adequate adhesion and wear resistance can be found for the CrTiBN coating as deposited at PEM set point of 40% and Ti target poisoning ratio of 60%.

Ln2NiO4+δ (Ln = La, Pr, Nd) coatings deposited by reactive magnetron sputtering as cathode material for intermediate temperature solid oxide fuel cell

This work focuses on the comparison of Ln-Ni-O coatings (Ln = La, Nd, Pr) deposited by reactive magnetron sputtering using Plasma Emission Monitoring (PEM) which allows high deposition rate. Each layer is deposited by different steps. The optimal regulation setpoint for oxide rare-earth deposition is determined and then the current dissipated on the nickel target is adjusted to obtain the convenient Ln/Ni ratio and to achieve the K2NiF4 structure. After an appropriate annealing treatment, all coatings exhibit crystalline structures, which depend on the Ln/Ni ratio. Due to the instability of Pr2NiO4 structure at intermediate temperatures, the crystallization step of praseodymium nickelate is performed at higher temperature than the other materials. This further thermal treatment implies a more porous structure. Each coating exhibits interesting properties. Electrical and electrochemical characterizations performed on these deposits prove better properties of the praseodymium nickelate coating.

Effects of sputtering mode on the microstructure and ionic conductivity of yttria-stabilized zirconia films

The microstructure and ionic conductivity of reactively sputtered yttria-stabilized zirconia (YSZ) films are systematically studied. Those films were reactively sputtered in various sputtering modes using a closed-loop controlled system with plasma emission monitoring. A transition-mode sputtering corresponding to 45% of target poisoning produces a microstructure with ultrafine crystallites embedded in an amorphous matrix, which undergoes an abnormal grain growth upon annealing at 800 °C. At 500 °C, the measured ionic conductivity of this annealed film is higher, by about a half order of magnitude, than those of its poisoned-mode counterparts, which are in turn significantly higher than that of the YSZ bulk by about two orders of magnitude. The abnormally-grown ultra-large grain size of the film deposited in the transition mode and then annealed is believed to be responsible for the former comparison due to the suppression of the grain boundary blocking effect, while the latter comparison can be attributed to the interface effect.

Magnetron sputtered TiOx layers: Structural, electrical, optical and thermochromic aspects

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 240nm and 38μm. The thermochromic behavior of a prepared Ti2O3 layer was measured and compared to calculations for bulk material.

Influences of target poisoning on the mechanical properties of TiCrBN thin films grown by a superimposed high power impulse and medium-frequency magnetron sputtering

Five TiCrBN coatings have been successfully fabricated by adopting hybrid co-deposition and superimposition concepts into high power impulse magnetron sputtering. The medium-frequency (MF) pulses were superimposed during the off-time of HiPIMS pulsing to Ti target. The direct-current (DC) and radio-frequency (RF) powers were connected to TiB2 and Cr targets, respectively. A plasma emission monitoring (PEM) system was used to grow thin films by tailoring the Ti target in transition and poisoning regimes, respectively. The different PEM set points, i.e., different target transition or poisoned regions, were selected to study their effects on the properties of deposited TiCrBN film. The deposition rate of TiCrBN films increased 1.64 times higher when the Ti target status changed from poisoning to transition regime by selecting PEM set points tuning from 30% to 70%. All samples exhibited a fine and dense microstructure, and a very smooth surface with the average roughness <1nm. The coefficient of friction and wear rate of each coating were in the ranges of 0.47–0.58 and 1.59–9.82×10−6mm3N−1m−1, respectively. The highest hardness of 38.9GPa, elastic modulus of 374GPa, acceptable adhesion quality of HF3 and upper critical load of 30N were obtained for T50% sample, which was grown at the PEM set point of 50%, in the transition region of Ti target and under the highest HiPIMS peak power density. This study also demonstrates the potential application of PEM apparatus attached to a superimposed HiPIMS-MF deposition technique for tailoring the growth of multicomponent metal nitride hard coatings.

Properties of Gadolinium-doped Ceria (GDC) Films Deposited by Reactive Magnetron Sputtering Processes

Reactive magnetron sputtering deposition technique was used for formation of gadolinium doped ceria oxide (GDC) thin films 5- 10µm. Material characteristics and chemical compositions of GDC films were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and 3D profilometry. In order to optimize the deposition of GDC to obtain high electrochemical performance of the cells, the influence of film thickness is studied. The GDC thin films were deposited on porous NiO–GDC (nickel oxide–Gadolinium stabilized ceria), the pre-sintered anode green tape were coated with a GDC electrolyte film by reactive magnetron sputtering using PEM (Plasma Emission Monitoring). An Alcatel SCM650 sputtering chamber was used for synthesizing the dense GDC layers. A Ce-Gd metallic target (90-10% at) was powered by a pinnacle + pulsed current generator from Advanced Energy. The structural, microstructural and morphological features of the half-cells were determined by XRD, SEM and 3D profilometry as deposited and after different annealing treatments. The obtained half-cell, 28 mm of diameter, anode supported solid oxide fuel cell, the porous and density of Ni-GDC10 composite anodes have been elaborated by tape casting method. The chosen ceramic powders in suspension were prepared with the mass ratio of 65:35 for NiO to GDC10. The microstructural morphological /porosity/surface features of the half-cell were analyzed by Scanning Electron Microscopy (SEM), XRD and 3D profilometry before and after different annealing treatment. Pycnometry and porosimetry techniques were primarily used to determine pore size and pore volume by equation Washburn and Ideal gas law-method. Finally, the EIS (Electrochemical Impedance Spectroscopy) measurements were done on Ni-GDC10/GDC10 half-cells under 60 sccm nitrogen by the means of a Solartron SI 1260 impedance / gain analyser from 20 MHz to 0.1 Hz with 11 points per decade.

Properties of Gadolinium-doped Ceria (GDC) Films Deposited by Reactive Magnetron Sputtering Processes

Reactive magnetron sputtering deposition technique was used for formation of gadolinium doped ceria oxide (GDC) thin films 5- 10µm. Material characteristics and chemical compositions of GDC films were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). In order to optimize the deposition of GDC to obtain high electrochemical performance of the cells, the influence of film thickness is studied. The GDC thin films were deposited on porous NiO–GDC (nickel oxide–Gadolinium stabilized ceria), the pre-sintered anode green tape were coated with a GDC electrolyte film by reactive magnetron sputtering using PEM (Plasma Emission Monitoring). An Alcatel SCM650 sputtering chamber was used for synthesizing the dense GDC layers. A Ce-Gd metallic target (90-10% at) was powered by a pinnacle + pulsed current generator from Advanced Energy. The structural, microstructural and morphological features of the half-cells were determined by XRD and SEM as deposited and after different annealing treatments. The obtained half-cell, 28 mm of diameter, anode supported solid oxide fuel cell, the porous and density of Ni-GDC10 composite anodes have been elaborated by tape casting method. The chosen ceramic powders in suspension were prepared with the mass ratio of 65:35 for NiO to GDC10. Finally, Pycnometry and porosimetry techniques were primarily used to determine pore size and pore volume by equation Washburn and Ideal gas law-method.

Effect of total pressure on La 2 NiO 4 coatings deposited by reactive magnetron sputtering using plasma emission monitoring

Abstract This work focuses on the structural, microstructural, electrical and electrochemical characterization of La–Ni–O coatings deposited by reactive magnetron sputtering under different argon partial pressures. Deposition was driven by Plasma Emission Monitoring system (PEM) which allows high deposition rate. For each pressure, the optimal regulation setpoint for lanthanum oxide deposition is determined and then the current dissipated on the nickel target is adjusted to obtain the convenient La/Ni ratio to achieve the K 2 NiF 4 structure. After an appropriate annealing treatment, coatings crystallize in the desired structure with more or less impurities. Increasing the device's pressure from 0.4 to 4.8 Pa produces more porous samples with different microstructures. Then, a coating with porosity gradient was built by using these four different total pressures. Its electrical performances were tested and allowed its utilization as cathode layer in intermediate temperature-solid oxide fuel cell (IT-SOFC). This modified architecture cathode allows better performances (71 mW·cm − 2 ) than dense cathode produced by the same technique (51 mW·cm − 2 ).

Sputtering Deposition of VO$lt;inf$gt;2$lt;/inf$gt; Film Using Plasma Emission Monitor as Reactive Gas Flow Rate Feedback Control

Monoclinic VO2 film was deposited on quartz substrate by reactive sputtering using the plasma emission monitor (PEM) system as reactive gas flow rate feedback control. Relationship between oxygen flow rate and plasma emission intensity was studied. It was found that single-phase VO2(M) could be obtained steadily at specific relative emission intensity (REI), which were determined as 0.6-0.65, 0.65 and 0.6 for total deposition pressure of 0.8 Pa, 0.5 Pa and 0.2 Pa, respectively. XRD measurement indicated that the deposited VO2 films were strongly oriented of (011) and the XPS measurements verified stoichiometry of the films as VO2.02. Optical transmission measurement of VO2 film exhibited an abrupt change of transmittance from 81% to 16% as VO2 film switched from semiconductor state to metallic state, at transition temperature of 66℃.

Synthesis and characterization of La2NiO4 + δ coatings deposited by reactive magnetron sputtering using plasma emission monitoring

This work focuses on the structural and electrical characterization of La–Ni–O coatings deposited by reactive magnetron sputtering using Plasma Emission Monitoring (PEM) which allows high deposition rate. The optimal regulation setpoint for lanthanum deposition is determined and then the current dissipated on the nickel target is adjusted to obtain the convenient La/Ni ratio to achieve the K2NiF4 structure. After an appropriate annealing treatment, all coatings exhibit crystalline structures that depend on the La/Ni ratio. Some cracks appear on samples deposited on alumina substrates depending to the argon flow rate and influence their electrical behavior.