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Microwave plasma (generation frequency 2.45 GHz, power 200–1000 W, pressure 0.2–10 mTorr) is excited and maintained in two main modes: (1) at continuous microwave power and low magnetic fields (B = 300–450 G) under a superdense (Ne > Ncr = 7.4 × 1010 cm−3) plasma and low plasma density (Ne < Ncr); and (2) in high magnetic fields (B = 750–1000 G), close to the ECR condition. The peculiarities of plasma generation under the ECR condition and at the second harmonic of cyclotron resonance are studied. [ABSTRACT FROM AUTHOR]

In this study, it is aimed to investigate Electromagnetic Shielding Interference (EMI) and Ultraviolet-Infrared (UV-IR) shielding behavior of nanocomposite textile fabrics produced by using Electron Cyclotron Resonance (ECR) and Thermal Evaporation methods together. For this purpose, Kevlar and polyester/elastane (PES/EL) fabric samples are coated with carbon, graphite, ZnO, and indium in different compositions and structures. Then, EMI shielding and UV-IR absorption performance of the samples are measured and analyzed. As a result, multiple nano-transition layers having different refractive indices formed on the coated surfaces improve the EMSE and UV-IR shielding performance. It is concluded that the carbon + graphite + ZnO coated Kevlar samples provides best EMI shielding performance. The highest EMSE values greater than 80 dB are obtained at six frequencies in the 15–60 GHz range. It is observed that the best coating quality is also produced on the same fabric sample. It is also found that the EMI shielding performance of Carbon coated Kevlar sample is significantly higher than the Carbon coated PES/EL sample. The UV-IR analysis shows that the carbon or/and ZnO coating on Kevlar fabric and the indium coating on PES/EL fabric have significant effect to improve UV/IR shielding properties. The carbon coated Kevlar fabric increases the absorption efficiency by 11.11% and the carbon + graphite + ZnO coated sample by 13.45% compared to the uncoated fabric. For the PES/EL samples, the carbon coating increases the absorption efficiency by 2.3% and the In coating by 12.6% compared to the uncoated fabric. Consequently, the carbon + graphite + ZnO nanocomposite coated Kevlar fabric (∼ 3.5 a.u.) has consistently and significantly higher absorption performance than the In coated PES/EL fabric (∼ 3.0 a.u.) in the 400–1200 nm. So, it has been concluded that the specific structure of the fabric to be coated is as effective as coating material. [ABSTRACT FROM AUTHOR]

Dry etching process of thin copper films using high electron temperature ECR (electron cyclotron resonance) plasma source is developed. With ECR source and RIE (reactive ion etching) mode, etching rate of 175 nm/min is achieved. Dry etching is performed under high electron temperature plasma source with low temperature substrate and employing a reactive ion etching mode. To compensate the large area etching uniformity, scanning low temperature susceptor is adopted. Rectangular‐type microwave slot antenna (ReSLAN) is used to generate ECR plasma. [ABSTRACT FROM AUTHOR]

We have demonstrated a capacitively coupled Hall‐type MHD generator using ECR plasma. To clarify the characteristics of the fabricated MHD generator, we measured the power generation characteristics as a function of magnetic field strength using a DC Hall‐type MHD power generation experiment. The results showed that the output power decreased due to magnetic pressure at the higher magnetic field. However, the output power corresponded to the theoretical value at the lower magnetic field. An AC Hall‐type MHD power generation experiment was conducted using an AC magnetic field. As a result, full‐wave rectification voltage was observed as per theory. Finally, capacitively coupled Hall‐type MHD power generation experiments were conducted, and full‐wave rectified waveforms were observed as in AC Hall‐type MHD power generation. These waveforms were similar to the output waveforms predicted from theory. These results show that the capacitively coupled Hall‐type MHD generator is feasible. [ABSTRACT FROM AUTHOR]

This paper presents Gen. 2 (370 mm * 470 mm) size thin copper film dry etching performance that is etched by high electron temperature plasma source with low temperature substrate. Dry etching is performed using HCl gas in a reactive ion etching mode. In addition, scanning low temperature susceptor and the electron cyclotron resonance (ECR) plasma produced by rectangular‐type microwave slot antenna (ReSLAN) are used. [ABSTRACT FROM AUTHOR]

Lifetimes of radioactive nuclei are known to be affected by the level configurations of their respective atomic shells. Immersing such isotopes in environments composed of energetic charged particles such as stellar plasmas can result in β-decay rates orders of magnitude different from those measured terrestrially. Accurate knowledge of the relation between plasma parameters and nuclear decay rates are essential for reducing uncertainties in present nucleosynthesis models, and this is precisely the aim of the PANDORA experiment. Currently, experimental evidence is available for fully stripped ions in storage rings alone, but the full effect of a charge state distribution (CSD) as exists in plasmas is only modeled theoretically. PANDORA aims to be the first to verify these models by measuring the β-decay rates of select isotopes embedded in electron cyclotron resonance (ECR) plasmas. For this purpose, it is necessary to consider the spatial inhomogeneity and anisotropy of plasma ion properties as well as the non-local thermodynamic equilibrium (NLTE) nature of the system. We present here a 3D ion dynamics model combining a quasi-stationary particle-in-cell (PIC) code to track the motion of macroparticles in a pre-simulated electron cloud while simultaneously using a Monte Carlo (MC) routine to check for relevant reactions describing the ion population kinetics. The simulation scheme is robust, comprehensive, makes few assumptions about the state of the plasma, and can be extended to include more detailed physics. We describe the first results on the 3D variation of CSD of ions both confined and lost from the ECR trap, as obtained from the application of the method to light nuclei. The work culminates in some perspectives and outlooks on code optimization, with a potential to be a powerful tool not only in the application of ECR plasmas but for fundamental studies of the device itself.

This study experimentally examined several magnetic field topologies for the miniature microwave discharge cathode driven by water, which is indispensable for realizing water ion thrusters. The electron emission currents were measured for various operating conditions; microwave power, mass flow rate, and microwave frequency. The magnetic field topology with the magnetic field lines passing through the orifice hole without intersecting the cathode increased the electron emission current. This result agreed with the prediction derived from the 3D-Particle-in-Cell simulations with Monte Carlo collisions. The measured performance was 11.1 mA electron emission current at 2.0 W microwave forward power and 20 μ g /s water mass flow rate. On the other hand, the dependency of electron emission current on magnetic field topology became smaller as the mass flow rate or microwave power decreased. Additionally, the performance dependency on mass flow rate was remarkably different by the magnetic field topology. We explained those newly found trends by the difference in electron temperature dependency for the electron transport against the magnetic field lines. • Magnetic field topology of the cathode was changed to improve the performance. • Electron emission current of 11.1 mA was achieved with input power of 2 W. • Performance trends against mass flow rate varied between magnetic field topologies. • Electron transport model explains performance trends against mass flow rate. [ABSTRACT FROM AUTHOR]

We have investigated the ferroelectric hafnium nitride (HfN) thin films directly formed on the Si(100) substrate for the metal-ferroelectrics-Si field-effect transistor (MFSFET) applications. The 10 nm thick rhombohedral phase HfN layer was found to be formed on the Si(100) substrate utilizing the post-metallization annealing (PMA) at 400°C/5 min for HfN0.5/HfN1.15/Si(100) MFS diode structure which was deposited with in situ process by the electron cyclotron resonance (ECR) plasma reactive sputtering. The remnant polarization (2Pr) of $24.0 \mu \text{C}$ /cm2 with the coercive field ( ${\text{E}_{c}}$ ) of 3.8 MV/cm was obtained from the P-V characteristic under the voltage sweep of ±10 V. Fatigue characteristics without wake-up were confirmed until 109 program/erase (P/E) cycles under the input pulses of ±6 V/ $5 \mu \text{s}$ although the 2 ${\text {P}_{r}}$ was gradually decreased to $10.7 \mu \text{C}$ /cm2. The polarization (Psw) of $13.4 \mu \text{C}$ /cm2 was clearly observed by the positive-up negative-down (PUND) measurements utilizing the input pulses of ±6 V/ $5 \mu \text{s}$ . The memory window (MW) of 0.32 V was realized in the C-V characteristics by the program operation at −10 V/1 s.

This paper presents the dry etching performance and expectation of highly conductive thin metal films that are hardly etched at low temperature with conventional plasma dry etching equipment. Dry etching is performed using a combination of H2 and HCl gases in a reactive ion etching system with low temperature susceptor and electron cyclotron resonance (ECR) plasma source. We could achieve high electron temperature enough to dissociate and ionize H and Cl radicals from H2 and HCl molecules. [ABSTRACT FROM AUTHOR]

• Effects of space radiations on polyimide. • Electron irradiation enhances erosion by atomic oxygen. • Erosion yield doubled in polyimide. Erosion studies of polyimide, exposed to high energy electrons and atomic oxygen, is necessary in view of its application in space vehicles. Here we present the erosion studies and degradation characteristics of polyimide after its sequential exposure to 1 MeV pulsed electron beam from Microtron accelerator and ~12 eV oxygen ions from a plasma reactor in the laboratory. The fluence of electrons was varied from 5 × 1014 to 2.0 × 1015 electrons/cm2 and that of oxygen ions from ~5 × 1016 to 2 × 1017 ions cm−2. The post irradiated and virgin polyimide samples were characterized by gravimetric analysis and contact-angle measurements. The morphological and spectroscopic information were obtained with Scanning Electron Microscopy, Fourier Transform Infra-Red spectroscopy, and photo-absorption spectroscopy. The erosion yield, surface wettability and the surface roughness were seen to be much higher when exposed to both the radiations as compared to either of them, reflecting the synergetic effects. [ABSTRACT FROM AUTHOR]

The authors redesigned the discharge chamber for the μ10 microwave discharge ion thruster to improve its thrust performance and succeeded in enhancing the maximum beam current and thrust efficiency. However, it was found that the ion current ratio extracted from the discharge chamber with the redesigned configuration was lower than that obtained with the original configuration. To investigate the relationship between ion extraction and the magnetic field geometry, the ion loss current distribution in these two types of discharge chamber were measured by electrostatic probes. Using planar probes with a guard ring, the ion current that flowed into the wall was measured without disturbing the ion beam current. The results show that ionization occurs mainly near the upstream magnet. In addition, the ion flux on the sidewall in the redesigned discharge chamber is about 1.5-2 times larger than that in the original discharge chamber. This suggests that the distance between the edge of the plasmaproduction region and the chamber wall with consideration of the Larmor radius of ions is an important parameter in discharge chamber design. In addition, although the ion beam current showed a tendency to saturate at high microwave power, the ion loss to each part in the discharge chamber increased in proportion to input microwave power. The decrease in the extracted ion ratio in the redesigned discharge chamber is considered to be caused by a decrease in the electrostatic ion transparency of the screen grid. Therefore, in a well-tuned microwave discharge ion thruster, it is difficult to improve the thrust efficiency by increasing the discharge power. A design that suppresses the wall loss of ions is thus important. • Ion loss in two types of ECR ion thrusters was measured in each parameter. • Ion beam is saturated as increasing input microwave power. • Ion loss distribution depends on magnetic lines geometry near the wall. • Ions are weakly magnetized and lost on the order of their Larmor radius. • Reducing the loss region by strengthening the magnetic field near the wall is important. [ABSTRACT FROM AUTHOR]

An electron cyclotron resonance (ECR) ion source (ECRIS) can generate an available amount of multicharged ions, thus it is not limited for use in the field of accelerator science, but also in medical/biological fields, such as for heavy ion beam cancer treatment and ion engines. The processes of generating multicharged ions are mainly sequential collisions of a direct ionization process by electrons, and have good ion confinement characteristics. By utilizing this confinement property, we have synthesized iron-encapsulated fullerenes, which are supramolecular and can be expected to have various high functions. Fullerenes and iron ions are vaporized from pure solid materials and introduced into the ECRIS together with the support gas. We investigated conditions under which fullerene ions do not dissociate and iron ions are generated so that both can coexist. Generated ions are extracted from the ECRIS and separated by mass/charge with a dipole magnet, and detected with a Faraday cup. This measurement system is characterized by a wide dynamic range. The charge-state distribution (CSD) of ion currents was measured to investigate the optimum conditions for supramolecular synthesis. As a result, a significant spectrum suggesting the possibility of iron-encapsulated fullerenes was obtained. This paper describes the details of these experimental results.

"Vertically aligned graphene nanosheets" are a type of graphitic carbon nanostructure with an interconnected network of perpendicularly aligned graphene nanosheets. In this study, the thin films of this material are deposited on stainless steel substrates using electron cyclotron resonance–based plasma-enhanced chemical vapor deposition. The variation of the electrochemical performance of the vertically aligned graphene nanosheets with the change in surface morphology is analyzed. The samples with different surface geometries offer different values of specific capacitances. The sample with nanopores between the graphene nanosheets of largest diameter and of most open nature delivers the highest specific electrode capacitance of 0.98 mF cm−2 (11.09 F cm−3) at a current density 0.88 mA cm−2 while the corresponding value for the sample with the smallest gap between nanosheets is of 0.49 mF cm−2 (6.67 F cm−3). The results point out at a direct correlation between surface morphology and electrochemical performance of the material. [ABSTRACT FROM AUTHOR]

The sterilization of a small vial using electron cyclotron resonance (ECR) plasma was investigated. The ECR plasma was generated throughout the inside of the small vial, which was sealed with nonwoven fabric, by using magnetic configuration in which the ECR point was located inside the small vial. Moreover, it was demonstrated that the temperature of the small vial was finely controlled by the pulse width and pulse frequency of the pulsed microwave power. A biological indicator (BI), Geobacillus Stearothermophilus , containing 1 × 105 spores present inside the small vial was successfully inactivated in a total treatment time of about 14 min while maintaining treatment temperature of less than 65 °C. • Inner surface of vial is sterilized using ECR plasma. • Low temperature sterilization is achieved by pulsed drive of ECR plasma. • Sterilization was confirmed at locations other than the ECR point in the vial. • Plasma is generated only inside the vial by controlling the magnetic field distribution. [ABSTRACT FROM AUTHOR]

The thin film of a vertically aligned tree-like carbon nanostructure is synthesised to study its performance as a novel electrode material of the electrochemical capacitor. The individual constituent nanostructures of the film are multiwalled carbon nanotubes aligned perpendicular to the substrate with carbon films attached to it like branches. This unique nanostructured carbon thin film has a regular geometrical arrangement with a very high surface area due to the distinctive structural morphology along with a good contact with the conducting substrate on which it is directly deposited. This makes the material an attractive candidate as the electrode of an electrochemical capacitor. The performance of this nanostructured material has been studied in a symmetric two-electrode configuration. The material has shown an electrochemical double-layer capacitance-type behaviour, the characteristic of carbon-based electrodes, along with a good cyclic retentivity. The material has shown a specific capacitance of 0.55 mF cm−2 (3.7 F cm−3) at a current density of 0.88 mA cm−2, while the aligned carbon nanotube films of similar thickness has exhibited a specific capacitance of 0.08 mF cm−2 (0.66 F cm−3) for the same current density. [ABSTRACT FROM AUTHOR]

Abstract To improve the performance of the 10-cm-class microwave discharge ion thruster μ10 for use in future deep space exploration missions planned by the Japan Aerospace Exploration Agency (JAXA), a new discharge chamber was designed, and its performance was tested. The maximum beam current in the new discharge chamber geometry was 16% higher than that in the original geometry, which was used in the Hayabusa 2 space explorer, under the same discharge power. To investigate the reason for this performance improvement, the multi-charged ion ratio in the plume, the beam current density profiles, and the ion current in the discharge chamber were measured by probes. It was found that the multi-charged ion efficiency and the beam divergence efficiency in the redesigned configuration were not significantly different from those in the Hayabusa 2 configuration. This shows that the increase in the ion beam current enhances the thrust. In addition, it was confirmed that the total ion current inside the new discharge chamber is higher than that in the Hayabusa 2 configuration. The ion extraction efficiency, however, was lower than that in the Hayabusa 2 configuration. This suggests that the increase in the total ion current per unit of incident microwave power is the cause of the performance improvement. In the redesigned configuration, the thrust is 12.0 mN, the specific impulse is 3122 s, the discharge loss is 162 W/A, and the propulsion efficiency is 39.6% at the peak performance point. Highlights • An ion beam current increase of 16% was obtained by redesigning the discharge chamber of the μ10 thruster. • It was verified by E×B probe measurement that the beam current improvement was not due to multi-charged ion current. • It was confirmed by electrostatic probe measurement that total plasma current was increased. • A thrust of 12 mN and a total efficiency of 39.6% have been achieved at the peak performance point. [ABSTRACT FROM AUTHOR]

This paper reports the development of a method of using incoherent laser Thomson scattering (LTS) to directly measure the electron velocity distribution function (EVDF) within a plasma plume. In this method, a 532 nm wavelength laser is injected into a plasma and Thomson scattering is detected with a CCD camera and a triple-monochromator. First, the measurement settings (e.g., laser power, number of integrations, and data analysis) were validated through a comparison between a microwave cathode and a hollow cathode. The results indicate that lower laser power is required as the photo-ionization from the metastable state particles increases the Thomson scattering. Second, the EVDFs of the microwave cathode at the plume were investigated for various anode currents and propellant flow rates. The results suggest that the non-Maxwellian EVDF was clearly observed at the low propellant flow rate, and the propellant flow rate is a more important parameter for the non-Maxwellian EVDFs than the anode current. • Electrons at a hollow and microwave cathode's plume region were measured. • Electron properties were acquired by incoherent laser Thomson scattering. • Effects of laser power on photo-ionization were evaluated in both cathodes. • Measurements were conducted under various anode currents and propellant flow rates. • Non-Maxwellian distributions were observed in the microwave cathode plume. [ABSTRACT FROM AUTHOR]

Abstract The sterilization of a small vial using electron cyclotron resonance (ECR) plasma was investigated. The ECR plasma was generated throughout the inside of the small vial, which was sealed with nonwoven fabric, by using magnetic configuration in which the ECR point was located inside the small vial. Moreover, it was demonstrated that the temperature of the small vial was finely controlled by the pulse width and pulse frequency of the pulsed microwave power. A biological indicator (BI), Geobacillus Stearothermophilus , containing 1 × 105 spores present inside the small vial was successfully inactivated in a total treatment time of about 14 min while maintaining treatment temperature of less than 65 °C. Highlights • Inner surface of vial is sterilized using ECR plasma. • Low temperature sterilization is achieved by pulsed drive of ECR plasma. • Sterilization was confirmed at locations other than the ECR point in the vial. • Plasma is generated only inside the vial by controlling the magnetic field distribution. [ABSTRACT FROM AUTHOR]

Highly resistive and sufficiently stiff insulation layers are an important prerequisite for the direct integration of piezoceramic modules into microstructured aluminium alloy sheets to produce smart adaptronic metal parts. In this study, we evaluate the mechanical and electrical properties of amorphous, hydrogenated silicon carbonitride films (a-SiCN:H) deposited by electron cyclotron resonance plasma CVD. First, we find the optimal process parameters for silicon substrates which we then transfer to electroded lead zirconate titanate (PZT) plates. Deposition rate, Young's modulus, stoichiometry and resistivity of a-SiCN:H films are determined by stylus profilometry, nanoindentation, X-ray photoelectron spectroscopy, elastic recoil detection analysis and current-voltage measurements, respectively. Under a 100 kHz bipolar pulsed substrate bias, 2 … 3 μm thick, well insulating films with Young's modulus ≈100 GPa are deposited at high rate of up to 7 μm/h. The electrical performance of a-SiCN:H films on PZT substrates is, to large extent, governed by the size and number of PZT roughness peaks, locally enhancing the field strength. Furthermore, we briefly address the deposition of the electrode layer on PZT. The selected material, sputter-deposited CuCr1Zr alloy, considerably improves the fracture strength of PZT substrates. [ABSTRACT FROM AUTHOR]

Dry etching characteristics of single crystal (100) CdTe epitaxial layers grown on GaAs substrates were studied using CH, H, and Ar as process gases in an electron cyclotron resonance plasma. A smooth and anisotropic etching was obtained with CH, H, and Ar. No hydrocarbon polymer was found on the etched surface, which was confirmed by x-ray photoelectron spectroscopy measurement. Etching of the CdTe surface was also possible with H and Ar; however, no etching was observed in the absence of H. Dependence of the etch rate on plasma gas composition and flow rates was studied. Mechanisms of etching with and without CH supply were also studied. Etched CdTe layers also showed no deterioration of electrical properties, which was confirmed by photoluminescence measurement at 4.2 K and Hall measurement at 300 K. [ABSTRACT FROM AUTHOR]

By introducing DC negative-biased Co target in the Electron Cyclotron Resonance (ECR) nitrogen/argon plasma, the Co-N films containing Co 4 N phase were synthesized on Si(100) substrate. Effects of processing parameters on magnetic properties of the films are investigated. It is found that magnetic properties of Co-N films vary with N 2 /Ar flow ratio, substrate temperature, and target biasing voltage. The saturation magnetization M s decreased by increasing the N 2 /Ar gas flow ratio or decreasing target biasing voltage, while the coercive field H c increased, which is ascribed to the variation of relative concentration for N or Co active species in plasma vapor. The magnetic properties present complex dependency with growth temperature, which is related to the atom mobility on the substrate affected by the growth temperature. This study exhibits a potential of ECR plasma chemical vapor deposition to synthesize the interstitial compounds and tune magnetic properties of films. [ABSTRACT FROM AUTHOR]

Titan hazes, and their laboratory analogs, named tholins, have been extensively studied in the laboratory. Previously, cold plasmas, such as radio frequency discharge, were the dominant plasma sources to produce energetic electrons and ions to simulate photoelectrons. In this work, the electron cyclotron resonance (ECR) discharge plasma was extended to study the formation of hazes encountered in Titan's upper atmosphere. ECR plasma has many advantages such as the electrons being cyclotron accelerated with a broad-energy-spectrum that can dissociate nitrogen, and with the temperature of the ions and neutrals remaining at room temperature. In addition, ECR plasma is free of radio-frequency interference, which ensures that the background parameters and processes can be precisely measured. The N 2 / CH 4 gas mixtures were discharged under different pressures and CH 4 mixing ratios, and the basic plasma parameters, emission spectra and gas composition, as well as the parameters related to the molecular weight functional groups of the reaction products were detected simultaneously during the reaction. The optical emission spectra show that the increasing production of CN species was observed with the addition of CH 4. In addition, the solid products were collected and analyzed using infrared spectroscopy and mass spectrometry, and the results are generally consistent with previous works. In summary, the ECR plasma has unique advantages and can provide an alternative energy source to study the generation of hazes encountered in Titan's upper atmosphere. • The electron cyclotron resonance (ECR) discharge plasma was extended to study the formation of tholins in this work. • The electrons can be cyclotron accelerated with a broad-energy-spectrum that can dissociate nitrogen using ECR plasma. • The work provides an alternative way to study the generation of hazes in Titan's upper atmosphere in the laboratory. [ABSTRACT FROM AUTHOR]

A two-step electron-ion hybrid irradiation process in electron cyclotron resonance (ECR) plasma was proposed as a flexible method to obtain carbon film with low roughness and electrical conductive surface. By the combination of either electron irradiation or ion irradiation during and after film deposition, two modes of hybrid irradiation were realized: In i-e hybrid mode, smooth amorphous carbon film was firstly deposited under ion irradiation, and its electrical resistivity was reduced from 1.4 to 0.12 Ω·cm − 1 after 5-min electron irradiation. In e-i hybrid mode, conductive graphene nanocrystallited film was firstly deposited, and its surface Ra roughness was decreased from 15.7 to 0.063 nm after 5-min ion irradiation. The top surface structural transition under electron irradiation in the i-e mode were demonstrated by transmission electron microscopy (TEM), Raman spectra, X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM), and the effective depth of electron irradiation on carbon film surface were discussed. This study provided a practical route to the massive production of ultra-smooth carbon films with novel nanostructure and outstanding physical properties for potential applications in nano-machinery and nano-devices. The hybrid irradiation method also expanded the way of plasma utilization in the fields of film deposition and surface modification, and will inspire various new films and coatings with improved top surfaces. [ABSTRACT FROM AUTHOR]

Vertically aligned graphene nanosheets (VAGNS) are grown by plasma enhanced chemical vapor deposition (PECVD) using electron cyclotron resonance (ECR) plasma system for application as an anode material in lithium ion battery (LIB). Microwave assisted etching, in presence and absence of substrate bias, is carried out on as grown VAGNS films to modify the morphology of the film. Scanning electron microscopy (SEM) is used for characterizing the surface features of the VAGNS films. The VAGNS sample which is microwave plasma treated (power 400 W) with substrate bias of 100 V, showed an initial charging specific capacity of 223 μAh·cm −2 ·μm −1 , while as deposited VAGNS showed specific capacity of 124.4 μAh·cm −2 ·μm −1 . After 5 cycles, while the former showed a specific capacity of 68.1 μAh·cm −2 ·μm −1 (760.7 mAh g −1 ), while the later showed a specific capacity of 43.9 μAh·cm −2 ·μm −1 (458.7 mAh·g −1 ). During discharge initially while surface modified VAGNS showed a capacity of 100.1 μAh·cm −2 ·μm −1 , the as deposited VAGNS showed a capacity of 38.2 μAh·cm −2 ·μm −1 . The specific capacity after five cycles, during discharge for modified VAGNS is 68 μAh·cm −2 ·μm −1 (725.9 mAh g −1 ), and for as deposited VAGNS it is 34 μAh·cm −2 ·μm −1 (380.6 mAh·g −1 ). The specific capacity remains fairly constant after this initial capacity loss up to 50 cycles. The results indicate that surface modification of VAGNS improves the performance of the material as anode for lithium ion battery. [ABSTRACT FROM AUTHOR]

The hydrogenation of polycrystalline SiGe layers, obtained by solid phase crystallization, by an electron ciclotron resonance hydrogen plasma and the influence of this hydrogenation process on the electrical characteristics of thin film transistors fabricated using this material as active layer have been studied. The hydrogenation processes were carried out at 150 and 250 ºC for several times, up to 11 hours. Infrared transmission spectra of these samples show only the absorption bands corresponding to Si-H bonds, indicating that hydrogen atoms are bonded mainly to silicon atoms. Ultraviolet reflectance measurements show that the surface damage caused by the plasma exposure increases as the Ge content of the film does. The transistors fabricated using polycrystalline SiGe films as active layer show a degradation phenomenon, consisting of a progressive decrease of the drain current at constant gate and drain bias. The degradation slows down as the hydrogenation time increases at constant temperature.En este trabajo se ha caracterizado el proceso de hidrogenación en un plasma generado por resonancia ciclotrónica de electrones de capas de SiGe policristalino obtenidas mediante cristalización en fase sólida y el efecto de la hidrogenación en las características eléctricas de transistores de película delgada fabricados usando dicho material. Los procesos de hidrogenación se realizaron a 150 y 250 ºC, con duraciones de hasta 11 horas. Los espectros de transmitancia en infrarrojo muestran solamente las bandas de absorción características de los enlaces Si-H. Estas bandas indican que el hidrógeno se incorpora al material enlazándose principalmente con los átomos de silicio. Las medidas de reflectancia en el ultravioleta indican que se crea daño en la superficie de la muestra y que éste aumenta a medida que lo hace el contenido en Ge. Los transistores de película delgada con capa activa de SiGe policristalino muestran un fenómeno de degradación consistente en que la corriente que atraviesa el canal disminuye con el tiempo manteniendo fijas las condiciones de polarización. La hidrogenación de los transistores hace que la degradación sea cada vez más lenta a medida que aumenta el tiempo de proceso en plasma a temperatura constante.

MIS structures have been fabricated on Si (111) by a two-step process: first an exposition of the Si substrates to an ECR oxygen plasma was performed, which yields a layer of SiOx (in the following PO-SiOx); this process was followed by an ECR plasma silicon nitride deposition (SiN1.55:H). The resulting MIS structure is Al/SiN1.55:H/PO-SiOx/Si. Devices have been characterized by the simultaneous measurement of the capacitance at high and low frequencies. This measurement lets us know the PO-SiOx/Si interface quality, calculate the thickness of the PO-SiOx layer and the growth rate of SiN1.55:H. To characterize the oxidation process some series of samples were prepared. In each series a process parameter was varied. These parameters were: the SiN1.55:H deposition time, the ECR plasma oxidation duration, the substrate temperature and the total oxygen flux. The bonding structure of the stacked dielectric has been studied by infrared spectroscopy. The stacked dielectrics spectra showed the superposition of two peaks: a less intense peak associated to the PO-SiOx layer with its maximum in 1056 cm-1, and another one due to the SiN1.55:H film with its maximum in 860 cm-1. These measurements showed that the PO‑SiOx growth law is dSiO = 2.7 tox 0.26 nm where dSiO is the PO-SiOx layer thickness and tox is the oxidation time in min. Concerning electrical characteristics, stacked MIS devices showed interface trap density minimums (Dit) close to 1011 eV-1cm-2. This value is inferior to the one that non-oxydized devices (Al/SiN1.55:H/Si) show. Also, stacked devices presented higher Fermi level sweeps and an electrical hysteresis almost insignificant.Se han fabricado estructuras MIS sobre Si (100) mediante un proceso en dos pasos: una primera exposición del sustrato de Si a un plasma ECR de oxígeno, que da lugar a la obtención de una capa de SiOx (en adelante PO-SiOx), seguido de un depósito de nitruro de silicio (SiN1.55: H) mediante plasma ECR. La estructura MIS resultante es de la forma Al/SiN1.55:H/PO‑SiOx/Si. Los dispositivos han sido caracterizados mediante la medida simultánea de las capacidades a alta y baja frecuencia, lo que permite conocer la calidad de la intercara PO‑SiOx/Si, calcular los espesores de la capa de PO‑SiOx y la velocidad de crecimiento del SiNx:H. Para caracterizar el proceso de oxidación se realizaron varias series de muestras variando en cada una un parámetro del proceso. Estos parámetros fueron: el tiempo de depósito del SiNx:H, el tiempo de oxidación, la temperatura del sustrato y el flujo total de O2. Asimismo, se ha estudiado la estructura de enlaces del dieléctrico apilado mediante espectroscopia infrarroja. El espectro del dieléctrico apilado mostró la superposición de dos picos: uno de menor intensidad asociado al PO‑SiOx con el máximo en 1056 cm-1, y otro debido al SiN1.55:H con máximo en 860 cm-1. Estas medidas mostraron que la ley que rige el crecimiento del PO‑SiOx es dSiO = 2.7 tox 0.26 nm donde dSiO es el espesor de la capa de PO-SiOx y tox es el tiempo de oxidación en min. Por lo que respecta a las características eléctricas, las estructuras presentaron mínimos de la densidad de trampas en la intercara (Dit) cercanos a 1011 eV-1cm-2. Este valor es inferior al que presentaron las estructuras sin oxidar, del tipo SiN1.55:H/Si. Además, los dispositivos apilados mostraron un barrido del nivel de Fermi mayor y una histéresis prácticamente despreciable.

In this report, the mass and energy spectra of ions in Ar/N 2 electron cyclotron resonance (ECR) plasma at the microwave power of 100 W and the gas pressure of 1 Pa are investigated by a Hiden EQP analyzer, and also the plasma optical emission spectra are recorded by optical emission spectroscopy (OES). Singly charged Ar + and N 2 + as the dominant ions are detected. The ion energy distribution functions (IEDFs) of Ar + and N 2 + exhibit complicated evolutions of peak structures with varying the N 2 fractions. The IEDF of Ar + is bimodal at the low N 2 fractions, and changes to trimodal structure as the N 2 fractions are near 40%. However, it turns to be unimodal at the N 2 fractions above 80%. The IEDFs of N 2 + present unimodal structures in the case of both high and low N 2 fractions, and the bimodal profiles appear as the N 2 fractions are around 50%. It is suggested that the distributed ionization and the charge–exchange reactions between ions and neutrals are responsible for the evolutions of peak structures for IEDFs. [ABSTRACT FROM AUTHOR]

The paper presents an improved method of depositing nanocrystalline thin films of Fe-doped TiO2 to be used as a reusable cyclic photocatalyst for degrading the organic pollutants. The technique of electron cyclotron resonance plasma-enhanced chemical vapor deposition was employed with titanium tetra-isopropoxide (C12H28O4Ti) and ferrocene (C10H10Fe) as precursors of Ti and Fe, respectively. Optical emission spectroscopy was used to identify the reactive species, to determine the electron temperature and the ion density during deposition. The films were characterized using optical absorption and photoluminescence spectra, whereas the morphological analysis was carried out with scanning electron microscopy. Strong adhesion of the deposited films with the substrate ruled out any possibility of TiO2 particles being leached out. It was confirmed by observing the degradation rate of the same film repeatedly. Cyclic use of the film for the catalytic reactions thus makes the process much user friendly for the water treatment. [ABSTRACT FROM AUTHOR]

The investigations reported here describe the synthesis of carbon nanowalls (CNWs) by microwave electron-cyclotron resonance (ECR) plasma-assisted chemical vapour deposition (PACVD) process without an application of external bias to the substrate during growth. CNWs were grown on silicon (Si) substrates using hydrogen (H2)/methane (CH4) plasma at 650°C substrate temperature. Nickel (Ni) was used as a catalyst for the synthesis of CNWs. To the best of our knowledge, this is the first report that describes the bias-independent growth of CNWs using the ECR PACVD process. Formation of CNWs is confirmed by scanning electron microscopy and Raman spectroscopy. The discussion part also includes a possible growth mechanism for CNWs in terms of the role of surface plasmons. [ABSTRACT FROM PUBLISHER]

Highlights: [•] The etching process of MPCVD diamond film was described. [•] The pyramidal crystallites of diamond film completely sunk. [•] An etching model of diamond film was proposed to explicate the etching mechanism. [Copyright &y& Elsevier]

Abstract: We produced a 915 MHz ECR plasma with TM01 microwaves for different magnetic flux density distributions and examined the radial profiles of the ion saturation current as a function of pressure and power. It was found that the 915 MHz ECR plasma is uniform over 200 mm in diameter around the L-cutoff density and when a diverging magnetic field is used, a low electron temperature plasma is realized. [Copyright &y& Elsevier]

There are very specific demands on the plasma processes used in various plasma technological applications. Microwave plasmas offer a wide range of applications for different pressures ranging from very low pressure (<0.1 Pa) over low pressure (0.1-100 Pa) and medium pressure (103-104 Pa) up to atmospheric pressure (105 Pa). This contribution is a short review on some microwave based plasma sources at different pressure ranges and a brief introduction into the plasma physics behind them (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

Abstract: The dissociative excitation reactions of CH3CN with the electron-cyclotron resonance (ECR) plasma flows of Ar and He were studied based on the electrostatic-probe measurements and on the optical emission spectra of the CN(B2Σ+ − X 2Σ+) transition. The density and the temperature of free electrons and the CN(B2Σ+ − X 2Σ+) emission intensity in these plasmas are varied by adding a trace amount of H2O. From the correlation between the CN(B2Σ+ − X 2Σ+) emission intensity and the electron density contributing to the dissociation process upon the addition of H2O, the formation of the CN(B2Σ+) state from the decomposition of CH3CN proceeds, predominantly, via the electron impact in the Ar plasma and via the electron impact and/or the ion–electron recombination in the He plasma. These results are found to be consistent with the evaluation of the number densities of CN(B2Σ+) using the steady-state method. In addition, hydrogenated amorphous carbon nitride films were prepared under the desiccated condition, and the compositional analysis was carried out, yielding the [N]/([N]+[C]) ratio of 0.22 and 0.25 for the Ar and He plasmas, respectively. [Copyright &y& Elsevier]

The dissociative excitation reaction of CH with the electron-cyclotron resonance plasma of Ar was investigated based on the electrostatic-probe measurements and on the optical emission spectroscopy of the CH(AΔ-XΠ) transition. The density, n, and the temperature, T, of free electrons were controlled by adding HO molecules externally into the reaction region, and the dependence of the CH(AΔ-XΠ) emission intensity on the addition of HO was observed to compare with the evaluated dependencies based on n and T. The mechanism of production of CH(AΔ) was found, predominantly, to be the electron impact with the contribution of 10-20% of the electron-impact dissociation of CH radicals; the contribution of the ion-electron recombination was negligible. Hydrogenated amorphous carbon films were fabricated using the same reaction system. The atomic compositions, Raman spectra, and the hardness of films were discussed in terms of the variations of n and T upon the addition of HO molecules. [ABSTRACT FROM AUTHOR]

Abstract: A new path to prepare cross-linked graphene layers embedded carbon (GLEC) films has been reported by introducing electron irradiation during the mirror-confinement electron cyclotron resonance (ECR) plasma sputtering process. The electron irradiation in the ECR plasma was identified by using Langmuir single probe equipped with a designed simulated substrate and the irradiation mode was found to be controlled directly by altering the substrate bias voltage. Cross-linked GLEC film was prepared using the electron irradiation in the pressure of 0.04Pa and positive bias voltage of 50V, and the nanostructure and binding configuration of the film were analyzed by high resolution transmission electron microscope (HRTEM) and X-ray photoelectron spectroscopy (XPS). The results showed that GLEC film contains cross-linked graphene layers grown normally to the substrate surface when the content of sp 2 hybridized carbon atoms in the film is more than 70%. The tribological behaviors of both cross-linked GLEC films and amorphous carbon films were compared using a Pin-on-Disk tribometer, and the mechanism for low friction coefficient was discussed by using HRTEM observation on wear track. The HRTEM results indicated that the cross-linked GLEC film has the potential to achieve low friction at the beginning of the friction. [Copyright &y& Elsevier]

Abstract: The passivation of crystalline Si solar cells using nitrous oxide (N2O) electron cyclotron resonance (ECR) plasma discharges has been studied and compared with ECR hydrogen passivation. The cells consisted of ECRCVD grown microcrystalline Si emitter layers on single crystal Si (sc-Si) and multicrystalline Si (mc-Si) substrates, without anti-reflective coatings or surface texturing. For cells on sc-Si substrates, hydrogen passivation is more effective at a substrate temperature of 300 °C and low microwave power (300 W). With increased power (500 W) H2 is less effective than N2O due to hydrogen plasma damage leading to a significant fall in the cell fill factor. In comparison with H2, N2O discharges lead to a significantly better (by > a factor of 2) improvement in the performance of cells on mc-Si substrates for treatment times of ≤15 min at a passivation temperature of 300 °C and 300 W microwave power. XPS measurements suggest that a surface oxide layer containing N and C atoms is formed by the N2O plasma which, most likely, reduces the surface state density and, hence, carrier recombination. [Copyright &y& Elsevier]

Abstract: A 2.45GHz electron cyclotron resonance (ECR) plasma source with a magnetron magnetic field configuration has been developed for the generation of high flux of hyperthermal neutral beams (HNB). The plasma potential in ECR plasma is required to obtain the HNB energy. In this study, the axial profile of the plasma potential was deduced from the ion kinetic energy distribution (IED) which was measured using an ion energy analyzer. It was found that the IED was broadened with a full width half maximum (FWHM), representing the difference between the maximum plasma potential and the minimum plasma potential. [ABSTRACT FROM AUTHOR]

Abstract: Diamond etching is characterized using a microwave ECR plasma reactor with regard to etch rate selectivity, surface morphology, and feature size. Etching is performed on diamond substrates using a variety of etch mask materials including aluminum, titanium, gold, silicon dioxide and silicon nitride. The etch feed gases are combinations of oxygen, sulfur hexafluoride and argon. Aluminum masks provided the highest selectivity ratio of diamond etch rate to mask etch rate, both with and without SF6 in the oxygen/argon feedgas. Selectivity was not found to be dependent on mask feature size. Gold masks produced the least degree of micromasking. [Copyright &y& Elsevier]

Abstract: To develop ECR plasma source for industrial applications, we produced a large diameter ECR plasma and examined radial profiles of the ion saturation current as a function of pressure and power. It was found that ECR plasma uniform over 300mm is produced for pressures higher than 1mTorr and the electron temperature decreases with increasing pressures. [Copyright &y& Elsevier]

Abstract: Two kinds of HfSiO x /interlayers (ILs)/Ge gate stack structures with HfGeN- and GeO2-ILs were fabricated using electron cyclotron resonance (ECR) plasma sputtering and the subsequent post deposition annealing (PDA). It was found that HfGe was formed by the deposition of Hf metal on Ge and changed to HfGeN by N2 ECR-plasma irradiation, which was used as IL. Another IL was GeO2, which was grown by thermal oxidation at 500°C. For dielectrics with HfGeN-IL, PDA of 550°C resulted in effective oxide thickness (EOT) of 2.2nm, hysteresis of 0.1V, and interface state density (D it)=7×1012 cm−2 eV−1. For dielectrics with GeO2-IL, PDA of 500°C resulted in EOT of 2.8nm, hysteresis of 0.1V, and D it =1×1012 cm−2 eV−1. The structural change of HfSiO x /GeO2/Ge during the PDA was clarified by using X-ray photoelectron spectroscopy, and the gate stack formation for obtaining the good IL was discussed. [Copyright &y& Elsevier]

Abstract: We report high quality Ti films grown in a novel electron cyclotron resonance (ECR) plasma-assisted magnetron sputtering (PMS) deposition system. The films are compared with films deposited by conventional direct current (DC) magnetron sputtering. Using ECR-PMS, the argon plasma bombardment energy and Ti film deposition rate can be controlled separately, with the substrate bias voltage under feedback control. Results from SEM, AFM, XRD and PAS (scanning electron microscopy, atomic force microscopy, X-ray diffraction and positron annihilation spectroscopy) show that the properties of Ti films prepared by ECR-PMS are greatly improved compared with conventional sputtering. SEM and AFM confirmed that ECR-PMS Ti films have a dense, smooth, mirror-like surface. Increasing the substrate bias of the ECR plasma from −23 V to −120 V while keeping a fixed sputtering bias voltage of −40 V, the intensity of the (100) reflection of Ti film was a little strengthened, but (002) remained strongly preferred orientation. The XRD peak broadening of ECR-PMS Ti films is more than for conventional magnetron sputtering, due to grain refinement induced by Ar ion bombardment. Doppler broadening of PAS analysis reveals that the Ti films have fewer vacancy defects compared with films prepared by the conventional magnetron. [Copyright &y& Elsevier]

Abstract: Deposits of one dimensional nanowires of zinc with diameters of 90–120nm have been obtained by means of dc sputtering within an electron cyclotron resonance plasma reactor. The sputtering has been made effective by using a negatively biased cylindrical target. The structure of the nanocrystalline wires deposited on glass substrates were investigated with scanning electron microscopy, transmission electron microscopy and scanning tunneling microscopy. STM revealed that the structure of the one dimensional nanowires are ensemble of nanoclusters and nanowires with diameter of 4–5nm. The crystalline nature of the metallic nanowires was studied with X-ray and electron diffraction analysis. The native oxide present on the metallic wires was revealed by photoluminescent spectroscopy. Theoretical modeling has been used to explain the possible mechanisms operative inside the plasma which lead into deposition of zinc on the substrate starting from the precursor species. [Copyright &y& Elsevier]

Abstract: Carbon nitride (CN x ) thin films with high nitrogen content were deposited on Si (100) substrates by using electron cyclotron resonance nitrogen plasma assisted pulsed laser deposition (ECR-PLD), and their thermal stability were studied by examining their composition and bonding behaviors upon post-deposition heat annealing in vacuum and in nitrogen ambient. The as-deposited films contain nitrogen content varying around 50 at.% and are primarily amorphous containing several bonding configurations between carbon and nitrogen atoms with different bond components depending on bias voltage applied to the substrates. In addition to the D, G and L Raman bands reported for most CN x thin films, three prominent Raman peaks were observed at 170, 260 and 616 cm−1 from our as-deposited films. Composition analysis by Rutherford backscattering spectroscopy measurement and chemical structure characterization by Fourier Transform infrared spectroscopy and Raman scattering measurements showed that the ECR-PLD deposited CN x thin films are quite stable upon annealing in vacuum up to 750 °C. The CN x films exhibit even higher thermal stability in nitrogen ambient. [Copyright &y& Elsevier]

Abstract: The KEKCB is an electron cyclotron resonance ion source (ECRIS) operating at the microwave frequency of 18GHz and has successfully operated as the charge breeder at Tokai Radioactive Ion Accelerator Complex (TRIAC). Following an overview of the TRIAC, the recent operating results of the KEKCB have been demonstrated. Special attention was paid on the element-dependent charge breeding efficiency and the beam impurity originating from the ECR plasma of the KEKCB. [Copyright &y& Elsevier]

Abstract: Cathodic sputtering is demonstrated to be effective in synthesizing thin films of molybdenum nanoparticles. An electron cyclotron resonance plasma reactor has been used as the source. The particle size distribution is found to be controllable by proper choice of the cathodic bias potential. Sizes ranging between 20 and 30nm deposited at the optimum bias potential are found to exhibit a self assembled structure as observed by scanning tunneling microscopy. Field emission microscopic studies on these films supported on W have exhibited very stable emission current over a period of 3h. [Copyright &y& Elsevier]

The effects of external magnetic field on the characteristics of electron cyclotron resonance (ECR) discharge are investigated by means of simulation. The quasi-3-D particle-in- cell plus Monte Carlo collision (PIC/MCC) method is presented. Secondary electron emission model is applied to describe the interaction between electron and boundary, which is simulated by the Monte Carlo collision (MCC) approach. The spatiotemporal evolution of electron space distributions is shown. Electron density and temperature at the initial stage and steady state of ECR discharge with the different external magnetic field configurations are discussed. [ABSTRACT FROM AUTHOR]