A5048400398- Plasma Diagnostics and Applications
- Metal and Thin Film Mechanics
- Diamond and Carbon-based Materials Research
- Ion-surface interactions and analysis
- Plasma Applications and Diagnostics
- Catalytic Processes in Materials Science
- Dust and Plasma Wave Phenomena
- Thin-Film Transistor Technologies
- Semiconductor materials and devices
- Laser-induced spectroscopy and plasma
- Electrohydrodynamics and Fluid Dynamics
- Surface Modification and Superhydrophobicity
- Mass Spectrometry Techniques and Applications
- Magnetic confinement fusion research
- Copper Interconnects and Reliability
- Ionosphere and magnetosphere dynamics
- Atomic and Molecular Physics
- Advanced Chemical Physics Studies
- ZnO doping and properties
- Fusion materials and technologies
- Silicon Nanostructures and Photoluminescence
- Polymer Nanocomposite Synthesis and Irradiation
- Ammonia Synthesis and Nitrogen Reduction
- nanoparticles nucleation surface interactions
- Analytical chemistry methods development
Ruhr University Bochum
2015-2024
John Wiley & Sons (Germany)
2019
Max Planck Institute for Plasma Physics
1995-2018
The Coordinating Center
2016
Joint Research Centre
2010
CEA Paris-Saclay - Etablissement de Fontenay-aux-roses
2010
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2010
Fraunhofer Institute for Process Engineering and Packaging
2010
Max Planck Society
1993-2003
University of Illinois Urbana-Champaign
1997-2002
Hydrocarbon films were prepared by electron cyclotron resonance plasma deposition from different hydrocarbon source gases at varying ion energies. The used the saturated hydrocarbons CH4, C2H6, C3H8, C4H10 (n- and iso-) unsaturated C2H4 C2H2 as well mixtures of these with hydrogen. Film was analyzed in situ real-time ellipsometry, resulting ex ion-beam analysis. On basis large range parameters investigated, correlation between gas, parameters, film properties determined. are found to be...
The effluent of a microscale atmospheric pressure plasma jet (μ-APPJ) operated in helium with small admixture molecular oxygen (<1.6%) has been analyzed by means two independent diagnostics, quantitative beam mass spectrometry (MBMS) and two-photon absorption laser-induced fluorescence spectroscopy (TALIF). atomic density, the ozone density depletion have measured MBMS validated TALIF. Absolute densities up to 4.7×1015 cm-3 could be very good agreement between both diagnostics. In addition,...
Abstract The inactivation of bacteria and biomolecules using plasma discharges were investigated within the European project BIODECON. goal was to identify isolate mechanisms by combining dedicated beam experiments with especially designed reactors. reactors are based on a fully computer‐controlled, low‐pressure inductively‐coupled (ICP). Four these built distributed among consortium, thereby ensuring comparability results between teams. Based this combined effort, role UV light, chemical...
Reactive plasmas are highly valued for their ability to produce large amounts of reactive radicals and energetic ions bombarding surrounding surfaces. The non-equilibrium electron driven plasma chemistry is utilized in many applications such as anisotropic etching or deposition thin films high-quality materials with unique properties. However, the character high power densities make very complex hard understand. Mass spectrometry (MS) a versatile diagnostic method, which has, therefore,...
The use of plasmas as a reactive mixture ions, electrons and neutrals is at the core numerous technologies in industry, enabling applications microelectronics, automotives, packaging, environment medicine. Recently, even medical has made great progress. dominant character plasma often its non equilibrium nature with different temperatures for individual species plasma, neutrals. This opens up multitude reaction pathways which are inaccessible to conventional methods chemistry, example....
Abstract Physical vapor deposition (PVD) refers to the removal of atoms from a solid or liquid by physical means, followed those on nearby surface form thin film coating. Various approaches and techniques are applied release including thermal evaporation, electron beam ion-driven sputtering, laser ablation, cathodic arc-based emission. Some based plasma discharge, while in other cases composing ionized either due film-forming species they intentionally afterward. Here, brief overview various...
Thermal conductivities $\Lambda $ of amorphous carbon thin films are measured in the temperatures range 80--400 K using $3\omega method. Sample from soft a-C:H prepared by remote-plasma deposition ($\Lambda = 0.20$ W m$^{-1}$ K$^{-1}$ at room temperature) to diamond with a large fraction $sp^3$ bonded deposited filtered-arc source 2.2$ K$^{-1}$). Effective-medium theory provides phenomenological description variation conductivity mass density. The thermal good agreement minimum calculated...
The growth of hydrocarbon films (C:H films) from a methane plasma and their erosion by hydrogen are investigated means in situ ellipsometry. kinetic energy the ions impinging on surface during deposition is varied applying rf bias resulting dc self-bias ranging floating potential up to 100 V. In addition, substrate temperature room 600 K. direct comparison between indicates that dependence rate caused temperature-dependent due reactions with abundant atomic hydrogen. Furthermore, synergistic...
An atmospheric pressure microplasma jet is developed for depositing homogeneous thin films from C2H2. The adjustment of the gas flow through assures optimal conditions as well minimizes deposition inside jet. In addition, formation an argon boundary layer surrounding emerging plasma beam separates ambient atmosphere growth precursor. Thereby incorporation nitrogen and oxygen into deposited film suppressed. Soft polymerlike hydrogenated amorphous carbon (a-C:H) are at rate a few nm/s on area...
HiPIMS plasmas generate energetic metal ions at the substrate as a major difference to conventional direct current magnetron sputtering. The origin of these is still an open issue, which unraveled by using two fast diagnostics: time resolved mass spectrometry with temporal resolution 2 $\mu$s and phase optical emission spectroscopy 1 $\mu$s. A power scan from dcMS-like was performed, 2-inch titanium target sputter source argon working gas. Clear differences in transport well properties...
Microplasma jets are commonly used to treat samples in ambient air. The effect of admixing air into the effluent may severely affect composition emerging species. Here, a He/O2 microplasma jet has been analyzed helium and an atmosphere by molecular beam mass spectrometry. First, was recorded as function distance determine how fast admixes effluent. Then, spatial distribution atomic oxygen ozone compared with measurements atmosphere. Additionally, fluid model gas flow reaction kinetics...
Atmospheric pressure non-equilibrium plasmas (APPs) are effective source of radicals, metastables and a variety ions photons, ranging into the vacuum UV spectral region. A detailed study these species is important to understand tune desired effects during interaction APPs with solid or liquid materials in industrial medical applications. In this contribution, opportunities challenges mass spectrometry for detection neutrals from APPs, fundamental physical phenomena related sampling process...
Abstract Hydrogen production via plasma methane pyrolysis is investigated using a microwave torch (MPT) and gliding arc plasmatron (GAP). The performance of the two sources in terms conversion, product spectrum, energy efficiency compared. physical chemical properties produced carbon particles are conversion higher GAP than MPT. In MPT amorphous spherical volume source. stops after acetylene. acetylene into solid takes place heterogeneous reaction on top electrode surfaces instead. This...
Erosion of hydrocarbon films at room temperature due to argon ions and thermal atomic hydrogen is investigated in a particle-beam experiment. Physical sputtering by the observed energies ⩾200 eV reaches yield 0.5 an ion energy 800 eV. The measured yields are agreement with TRIM.SP computer simulations, threshold ≃58 derived for physical sputtering. simultaneous fluxes atoms all down 20 about 3 hydrogen-atom-to-argon-ion-flux ratio 400. It proposed that significant decrease as well increase...
The deposition of C:H layers by an electron-cyclotron-resonance plasma from methane was investigated. deposited at a pressure 1.6 Pa and substrate temperature between room 700 K. film composition, morphology, structure were investigated high-energy ion beam analysis scanning electron microscopy. A combined plasma-surface model for thin-film is proposed, which includes the electron-induced dissociation in growth model. dominant reactions are adsorption radical CH3, direct incorporation ions,...
A simple robust method is presented to determine the densities of metastable and resonant species in low temperature, pressure argon argon-diluted plasmas. The ratios spectral lines which correspond transitions from common upper states or lower are measured with resolution optical spectrographs. Photon reabsorption makes these sensitive population states. concept escape factors used develop a set nonlinear equations for line ratios, does not depend on By means least squares method, can be...
A rf microplasma jet working at atmospheric pressure has been characterized for Ar, He, and Ar∕CH4 Ar∕C2H2 mixtures. The microdischarge a coaxial configuration, with gap between the inner outer electrodes of 250μm. main flow runs through structure, while reactive gases are inserted capillary as electrode. discharge is excited using 13.56MHz, rms voltages around 200–250V currents 0.4–0.6A obtained. Electron densities 8×1020m−3 gas temperatures lower than 400K have measured optical emission...
The behavior of dual frequency capacitively coupled plasma discharges (2f-CCP) is experimentally studied by Langmuir probe and rf current measurements compared with simulations from the literature. driving ratio, system pressure, high (HF) power low (LF) are varied in experiments. An increase LF causes a moderate electron density but significant decrease temperature. HF strong populates energy part distribution function. These dependences can be explained on basis global model. It shown that...
An RF microplasma jet working at atmospheric pressure has been developed for thin film deposition application. It consists of a capillary coaxially inserted in the ceramic tube. The is excited by an frequency 13.56 MHz rms voltages around 200–250 V. plasma generated forming gas (helium or argon) annular space between and By adjusting flows, flow pattern prevents inside source mixing reactive species with ambient air discharge region, so that no traces are found even when operated atmosphere....
Organic and inorganic silicon dioxide films have been deposited by means of an atmospheric pressure microplasma jet. Tetramethylsilane (TMS), oxygen, hexamethyldisiloxane (HMDSO) are injected into argon as plasma forming gases. In the case TMS injection, if admixture oxygen is used. HMDSO can be at room temperature even without any admixture: low flow rates [&lt;0.1 SCCM (SCCM denotes cubic centimeters per minute STP),&lt;32 ppm], SiOxHz contain no carbon exhibit oxygen-to-silicon...
High power impulse magnetron sputtering (HiPIMS) is a deposition technique where metal target sputtered in high density plasma to synthesize thin layers with superior properties on substrate material.These plasmas are characterised by short pulses the range of 50 µs 200 and very peak powers several kW/cm 2 per area.The understanding these dynamic upmost interest for further development this coating technique.Fast camera measurements revealed formation localised ionisation zones that...
The rotation of localised ionisation zones, i.e. spokes, in magnetron discharge are frequently observed. spokes investigated by measuring floating potential oscillations with 12 flat probes placed azimuthally around a planar circular magnetron. 12-probe setup provides sufficient temporal and spatial resolution to observe the properties various such as direction, mode number angular velocity. function current, ranging from 10 mA (current density 0.5 cm−2) 140 A (7 cm−2). In range 600 plasma...
Abstract Pyrolysis of methane is a promising, new, greenhouse gas‐free production method hydrogen. Here, we present optical emission spectra microwave plasma torch operated in an argon–methane mixture. Detailed spatial resolution achieved by means Abel inversion. The are dominated dicarbon Swan bands and black body radiation from carbon nanoparticles. Both spectral features utilized to estimate the gas temperature. In center plasma, temperatures up 4300 K reached with large gradients (500...
The surface loss probabilities of hydrocarbon radicals on the amorphous hydrogenated carbon (C:H) films are investigated by depositing inside a cavity with walls made from silicon substrates. This is exposed to discharge using different source gases, and particles plasma can enter through slit. probability β determined analysis deposition profile cavity. corresponds sum effective sticking formation non-reactive volatile product via reactions. By comparing profiles measured in CH4, C2H2 C2H4...