A5067202183- Plasma Diagnostics and Applications
- Dust and Plasma Wave Phenomena
- Plasma Applications and Diagnostics
- Metal and Thin Film Mechanics
- Electrohydrodynamics and Fluid Dynamics
- Atomic and Molecular Physics
- Ionosphere and magnetosphere dynamics
- Magnetic confinement fusion research
- Electrostatic Discharge in Electronics
- Ion-surface interactions and analysis
- Laser-induced spectroscopy and plasma
- Semiconductor materials and devices
- Particle accelerators and beam dynamics
- Diamond and Carbon-based Materials Research
- Carbon Nanotubes in Composites
- Graphene research and applications
- Laser-Plasma Interactions and Diagnostics
- Plasmonic and Surface Plasmon Research
- Electron and X-Ray Spectroscopy Techniques
- Solar and Space Plasma Dynamics
- Copper Interconnects and Reliability
- Laser-Matter Interactions and Applications
- Mechanical and Optical Resonators
- Cold Atom Physics and Bose-Einstein Condensates
- High-pressure geophysics and materials
Dalian University of Technology
2015-2024
Materials Modification (United States)
2024
Jilin Agricultural University
2024
Ruhr University Bochum
2021
Dalian University
2009-2020
Huazhong University of Science and Technology
2014
University of Antwerp
2014
Lanzhou University
2006
Maxwell Technologies (United States)
2002
Vibrational and rotational temperatures were simultaneously determined in a kilohertz alternating current (ac) gliding arc discharge by using overlapped emission spectra of N2(C 3Πu–B 3Πg) with OH(A 2Σ+–X 2Πi) . The simulated largely radiation transition bands when the temperature was elevated from 500 K to 2500 K. temporally resolved vibrational voltage period suggested that remarkably larger than ratio number densities excited electronic states also based on spectra.
Abstract The influence of a uniform magnetic field parallel to the electrodes on radio frequency capacitively coupled oxygen discharges driven at 13.56 MHz pressure 100 mTorr is investigated by one-dimensional particle-in-cell/Monte Carlo collision (1D PIC/MCC) simulations. Increasing from 0 200 G found result in drastic enhancement electron and <?CDATA ${\mathrm{O}}_{2}^{+}$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:msubsup>...
Abstract One dimensional fluid/electron Monte Carlo (MC) simulations of capacitively coupled Ar/O2 discharges driven by sawtooth up voltage waveforms are performed as a function the number consecutive harmonics driving frequencies 13.56 MHz, N (1 – 3), pressure (200 500 mTorr) and gas mixture (10 90 % admixture O2 to Ar). The effects these external parameters on electron dynamics, transport ions neutrals revealed at constant peak-to-peak voltage. electronegativity is found decline increases...
Abstract A novel method of uniformity control in low pressure capacitively coupled radio-frequency plasmas by an individually driven sidewall electrode is proposed and verified two-dimensional kinetic simulations. At the electrode, energetic electron beams are generated sheath expansion heating propagate radially inwards towards reactor center. Upon reaching edge planar powered where wafer located plasma processing applications, they interact with time-modulated RF at this electrode....
Abstract The effects of the simultaneous presence two different types plasma asymmetry, viz, geometric and electrical, on low-pressure capacitively coupled argon discharges are studied by 2D3V graphics-processing-unit-based particle-in-cell/Monte Carlo simulations. asymmetry originates from powered vs grounded electrode surface areas, while electrical is established applying peaks/valleys sawtooth-up/-down driving voltage waveforms. While in geometrically symmetric discharges, {peaks ↔...
The electron bounce resonance heating (BRH) in dual-frequency capacitively coupled plasmas operated oxygen and argon has been studied by different experimental methods. In comparison with the electropositive discharge, BRH an electronegative discharge occurs at larger electrode gaps. Kinetic particle simulations reveal that bulk electric field becomes quite strong is out of phase sheath field. Therefore, it retards resonant electrons when traversing bulk, resulting a suppressed BRH. This...
Self-organized striated structure has been observed experimentally and numerically in CF4 plasmas radio-frequency capacitively coupled recently (Liu et al 2016 Phys. Rev. Lett. 116 255002). In this work, the is investigated a oxygen discharge with introduction of effect from secondary electron emission, based on particle-in-cell/Monte Carlo collision model. As we know, transport positive negative ions plays key role formation striations electronegative gases, for which, electronegativity...
Abstract Understanding the spatio-temporal dynamics of charged particles in low pressure radio frequency capacitively coupled plasmas (CCP) is basis for knowledge based process development these plasma sources. Due to importance kinetic non-local effects particle cell/Monte Carlo collision (PIC/MCC) simulation became primary modeling approach. However, due computational limitations most previous PIC/MCC simulations were restricted spatial resolution one dimension. Additionally, studies on...
Two classic radio-frequency (RF) plasmas, i.e., the capacitively and inductively coupled plasmas (CCP ICP), are widely employed in material processing, e.g., etching thin film deposition, etc. Since RF usually operated particular circumstances, low pressures (mTorr–Torr), high-frequency electric field (13.56 MHz–200 MHz), reactive feedstock gases, diverse reactor configurations, etc., a variety of physical phenomena, electron resonance heating, discharge mode transitions, striated...
Abstract Instabilities in capacitively coupled Ar/CF 4 plasma discharges driven by dual frequency sources are investigated using a one-dimensional fluid/electron Monte Carlo hybrid model. Periodic oscillations of the electron density and temperature on timescale multiple low (LF) periods observed. As increases, an intense oscillation within each high (HF) period is initiated. This causes fluctuation results discharge instability. phenomenon consistent with behavior observed scenarios...
An annular-mode gliding arc discharge powered by a 50 Hz alternating current (ac) supply was studied in vortex flow of dry and humid air. Its temporal evolution characteristics were investigated electrical measurement, temporally resolved imaging, optical emission spectroscopic measurements. Three stages arc-ignition, arc-gliding, arc-extinction clearly observed each half-cycle the discharge. During arc-gliding stage, intensity light from root at cathode remarkably higher than that other...
We study the wake effect in induced potential and stopping power due to plasmon excitation a metal slab by point charge moving inside slab. Nonlocal effects response of electron gas are described quantum hydrodynamic model, where equation electronic motion contains both pressure term gradient correction from Bohm potential, resulting fourth-order differential for perturbed density. Thus, besides using condition that normal component velocity should vanish at impenetrable boundary metal,...
The electron power absorption dynamics and plasma uniformity in low pressure capacitively coupled RF discharges with structured electrodes are investigated by graphics processing unit-based 2d3v particle-in-cell/Monte Carlo simulations argon gas. In the presence of planar electrodes, is radially nonuniform due to strong density peaks close reactor sidewall, which caused edge effects that locally enhance ionization. Such a local enhancement these characteristics can also be achieved...
The electron bounce resonance heating (BRH) in dual-frequency capacitively coupled plasmas operated oxygen is studied by different experimental methods and a particle-in-cell/Monte Carlo collision (PIC/MCC) simulation, compared with the electropositive argon discharge. In comparison argon, results show that an discharge peaks positive-ion density light intensity tend to occur at larger electrode gaps. Moreover, gaps L > 2.5 cm, (and electron) emission drop monotonically upon increasing L,...
Abstract The electrical asymmetry effect (EAE) enables separate control of the ion flux and mean energy in capacitively coupled plasmas (CCP). While a variety plasma processing applications benefit from this, large-area, very-high-frequency CCPs still suffer lateral nonuniformities caused by electromagnetic standing wave effects (SWE). Many such sources are geometrically asymmetric operated at low pressure so that high frequency nonlinear series resonance (PSR) oscillations RF current...
A theoretical model is presented to investigate the wave dispersion relation of a two-dimensional (2D) strongly coupled Yukawa system, taking into account constant magnetic field pointing perpendicular 2D within framework quasilocalized charge approximation. Numerical results represent dependence on strength, coupling parameter, and screening parameter. Both high-frequency low-frequency branches are shown as result longitudinal transverse modes due Lorenz effect. The obtained from analysis...
We consider a charged particle moving parallel to the surface of metal film covering on semi-infinite dielectric substrate with constant speed. By means linearized quantum hydrodynamic theory, induced electron gas density and stopping power are studied, taking into account statistical diffraction effects. The calculation results show that an oscillatory wake field appears apparently behind at both surfaces effect thickness cannot be neglected when is thinner. Besides, dependence thickness,...
Particle-in-cell/Monte Carlo collision simulations, coupled with an external circuit, are used to investigate the behavior of pulsed dual-frequency (DF) capacitively plasmas (CCPs). It is found that phase shift θ between high (or low) frequency source and pulse modulation has a great influence on ion density ionization rate. By pulsing source, time-averaged shows maximum when = 90∘. The energy distribution functions (IEDFs) at driven electrode, however, keep almost unchanged, illustrating...
Abstract The electrical asymmetry effect combined with the magnetic in a geometrically symmetric argon discharge is investigated using one-dimensional particle-in-cell simulation Monte Carlo collision model. Both effects can induce an asymmetric plasma response consequent dc self-bias. It found that these two work independently of each other to some extent, which greatly enhances flexibility for controlling ion properties interest, e.g. flux Γ i and mean energy <?CDATA $\left\langle...
A two-dimensional particle-in-cell (PIC) model is proposed to study the wake field and stopping power induced by a nonrelativistic charged particle moving perpendicular external magnetic in two-component plasmas. The effects of on potential due polarization both plasma ions electrons are discussed. velocity fields investigated, respectively, weak strong cases. Our simulation results show that case high ion velocity, wakes exhibit typical V-shaped cone structures opening angles decrease with...
Pulsed-discharge plasmas offer great advantages in deposition of silicon-based films due to the fact that they can suppress cluster agglomeration, moderate energy bombarding ions, and prolong species' diffusion time on substrate. In this work, a one-dimensional fluid/Monte-Carlo hybrid model is applied study pulse modulated radio-frequency (RF) sustained capacitively coupled Ar SiH4/Ar discharges. First, electron distributions pulsed have been investigated compared under identical...
A novel method, the so-called electrical asymmetry effect (EAE), is gaining increasing interest for realizing separate control of ion flux and energy. In this paper, a two-dimensional fluid model combined with full set Maxwell equations used to investigate plasma properties in an electrically asymmetric capacitive discharge sustained by multiple consecutive harmonics operating very high frequency regime. The results indicate that total number k, modulation dc self-bias induced changing (the...