A5053787085- Plasma Diagnostics and Applications
- Metal and Thin Film Mechanics
- Particle accelerators and beam dynamics
- Dust and Plasma Wave Phenomena
- Magnetic confinement fusion research
- Plasma Applications and Diagnostics
- Diamond and Carbon-based Materials Research
- Laser-induced spectroscopy and plasma
- Semiconductor materials and devices
- Electrohydrodynamics and Fluid Dynamics
- Electrostatic Discharge in Electronics
- Magnetic Field Sensors Techniques
- Physics of Superconductivity and Magnetism
- Advanced Condensed Matter Physics
- Integrated Circuits and Semiconductor Failure Analysis
- Thin-Film Transistor Technologies
- Manufacturing Process and Optimization
- Superconducting Materials and Applications
- Catalysts for Methane Reforming
- Chemical Synthesis and Analysis
- 3D IC and TSV technologies
- Organometallic Compounds Synthesis and Characterization
- Advanced Measurement and Metrology Techniques
- Semiconductor Lasers and Optical Devices
- Iron-based superconductors research
IMEC
2024
Korea Advanced Institute of Science and Technology
2003-2016
Pohang University of Science and Technology
2007
Institute of Physics
2003
Yonsei University
2000
The extensive design effort for KSTAR has been focused on two major aspects of the project mission - steady-state-operation capability and advanced tokamak physics. steady state aspect is reflected in choice superconducting magnets, provision actively cooled in-vessel components, long pulse current drive heating systems. incorporated features associated with flexible plasma shaping, double null divertor passive stabilizers, internal control coils a comprehensive set diagnostics. Substantial...
The evolution of the electron energy distribution function (EEDF) over a weak magnetic field range is investigated in magnetized radio-frequency (rf) inductive discharges under collisionless regime where an anomalous skin effect and cyclotron resonance (ECR) can occur. A significant change low-energy EEDF found ECR condition during evolution. observed result reveals electrons are efficiently heated by rf presence effect. calculated based on kinetic theory good agreement with experiment.
One-dimensional particle-in-cell Monte Carlo collision simulations of magnetized argon plasmas in an asymmetric capacitively coupled plasma reactor are presented. At low pressure (10mTorr), electron kinetics strongly affected by the magnetic field and transitions from nonlocal to local kinetic property occur with increasing which reflected spatially resolved calculations electron-energy probability function. For high-energy electrons, transition takes place when energy-relaxation length is...
As collisions between electrons and neutral particles constitute one of the most representative physical phenomena in weakly ionized plasma, electron-neutral (e-n) collision frequency is a very important plasma parameter as regards understanding physics this material. In paper, we measured e-n using calibrated cutoff-probe. A highly accurate reactance spectrum plasma/cutoff-probe system, which expected based on previous cutoff-probe circuit simulations [Kim et al., Appl. Phys. Lett. 99,...
The electron energy distribution functions and plasma parameters in various gas mixture discharges (N2,O2,CF4/He,Ar,Xe) are measured. When He is mixed, the temperature increases but density almost constant. rapidly near a mixing ratio of 1, it constant when small. In Ar discharge, constant; slightly Mixing Xe decreases temperature. varies similar way with that case. A simple two-ion-species global model used to analyze parameter variations as function ratio, agrees well experimental results.
The electron energy distribution functions and temperatures are measured in Ar/He Ar/Xe inductively coupled plasma with various mixing ratios. temperature does not change linearly the ratios; instead it increases abruptly near PHe/PAr+He=1 decreases rapidly PXe/PAr+Xe=0. A simple model using a two-ion-species fluid is suggested to explain variations, agrees well experimental results.
Pressure and He mixing effects on plasma parameters in electron temperature control using a grid system are investigated. Electron is higher lower pressure, when the high not controlled. density can be increased by about three times decreasing source gas pressure from 20 to 1 mTorr, two controlled region (diffusion region), while decreased region. This increase mainly due of energy population, measured distribution functions clearly show this.
The electron energy distribution functions (EEDFs) are measured by a rf compensated Langmuir probe in solenoidal inductive reactor at various frequencies and 2 mTorr of argon. frequency dependence the function is clearly observed. diffusion coefficients against applied calculated from nonlocal heating theory. It found that bounce resonance electrons determine coefficient shape begins to flatten. exact condition discharge presented. reported EEDFs mainly due finite-size discharge.
To elucidate plasma nonuniformity in high frequency capacitive discharges, Langmuir probe and B-dot measurements were carried out the radial direction a cylindrical discharge driven at 90MHz with argon pressures of 50 400mTorr. Through measurements, significant inductive electric field (i.e., time-varying magnetic field) was observed edge, it found that creates strong pressure operation. The operation is physically similar to E-H mode transition typically discharges. This result agrees well...
Curvilinear design was applied to standard cell layout improve electrical characteristics and reduce manufacturing costs. Its implementation intelligently co-optimized with 1-D Manhattan shapes photolithography process preserve the area equivalent that of Manhattan-only designs. B-spline curve representation employed realize curvilinear design. pathfinding carried out through Voronoi diagram find optimum routing path, A* algorithm determine shortest path. In curvilinear-designed cells,...
A study on the dependence of electron energy distribution function (EEDF) discharge gap size in capacitive rf discharges was conducted. The evolution EEDF over a range from 2.5to7cm 65mTorr Ar investigated both experimentally and theoretically. measured EEDFs exhibited typical bi-Maxwellian forms with low groups. significant depletion portion found decreasing size. results show that heating by bulk electric fields, which is main process low-energy electrons, greatly enhanced as decreases,...
Previous studies indicated that the measurement results of microwave probes can be improved by applying adequate sheath width to their models, and consequently around probe tips has become very important information for diagnostics. In this paper, we propose a method measuring argon plasma cutoff circuit model phase spectrum. The measured was found in good agreement with floated calculated from Child-Langmuir law. physical reasons discrepancy between two measurements are also discussed.
Recently, the technique for measurement of sheath width by using cutoff probe and its equivalent circuit model was proposed conducted experimentally. In this study, we investigate reliability based on computational simulation. The simulation three-dimensional Finite-Difference Time-Domain reproduces transmission spectrum with an input parameter width. We measure calculate discrepancy between them under various plasma densities widths. results show acceptable all conditions studied (the...
A theory is developed for the density profile of low temperature plasmas confined by applied magnetic field and an experiment electron-cyclotron-resonance (ECR) plasma conducted to compare theoretical prediction experimental measurements. Due a large electron mobility along field, electrons move quickly out system, leaving ions behind building space charge potential, which leads ambipolar diffusion ions. In steady-state condition, generation ionization neutral molecules in balance with loss...
The temporal measurement of gas pressure in inductive coupled plasma revealed that there is an interesting anomalous evolution the early stage ignition and extinction: a sudden change its relaxation which time scales are about few seconds tens second, respectively, were observed after extinction. This phenomenon can be understood as combined result between neutral heating effect induced by for new temperature. temperature laser Rayleigh scattering dependant calculations good agreement with...
Summary form only given: Wave-cutoff method using microwave provides capabilities for diagnostics of various processing plasmas, and can give the precise absolute electron densities. In this study, pressure limitation density measurement a wave- cutoff is presented. As gas increases, wave-cutoff signal disappears. The disappearance happens when electron-neutral collision frequency over plasma frequency. At that time, motion cannot catch up to movement electromagnetic wave, waves begin...
No. 60), a = 16.052(2)A, b= 11.523(1) A, c 8.236(1) V= 1523.3A 3 , Z 4, Rgi(F) 0.076, wR Ki (F 2 ) 0.250, T= 296 K.
Summary form only given. The CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> capture and storage technology (CCS technology) needs immediate action, but does not have complete solutions yet due to the efficient, economical conversion problems.In this presentation, governing fundamental quantities will be identified obtain maximum energy efficiency capacity for CO2 dissociation. Several ideas introduced, describing advantages...