• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.11a
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• pp.183-183
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• 2015

Arc in plasma processing chamber results in high current discharge marks and particles on wafers, but it is hard to identify or observe it during the proc ess. In this paper, we report the observations of plasma arc s during various plasma proc esses through a non-invasive optic al plasma monitoring system (OPMS) devised for the in-situ detec tion of abnormal discharge.

• Journal of Industrial Technology
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• v.19
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• pp.331-341
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• 1999

We analyzed theoretically the removal efficiency and the particle growth inside the pulse corona discharge reactor to remove $NO_x$ and investigated the effects of process variables such as the NO and $NH_3$ input concentrations. Most of NO is converted into $NO_2$ and $HNO_3$ and the $HNO_3$ reacts with $NH_3$ to form the $NH_4NO_3$ particles. About 6.4% of NO is converted into $HNO_2$ which form the $NH_4NO_2$ particles by reaction with $NH_3$. Some of $NO_2$ follows the reaction pathway to form $NO_3$ and $N_2O_5$. The amount of particles formed inside the reactor is basically determined by the input $NH_3$ concentration. The ratio of NO to $NH_3$ affects the reactor length for particle formation significantly. The higher the input concentrations of NO and $NH_3$ are, the faster the particles grow.

• Journal of Powder Materials
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• v.14 no.2 s.61
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• pp.116-122
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• 2007

It is well known that thermal plasma process has lots of advantages such as high temperature and good quality for synthesis of nano particles. In this research, we attempt the synthesis of nano unitary and composite powder (Ag, Mg-Al, Zr-V-Fe) using transferred thermal plasma. Nano particles of metal alloy, ranging from 20 nm to 150 nm, have been synthesized by this process.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.5
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• pp.401-409
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• 2013

Numerical analysis on RF (Radio-Frequency) thermal plasma treatment of micro-sized Ni metal was carried out to understand the synthesis mechanism of nano-sized Ni powder by RF thermal plasma. For this purpose, the behaviors of Ni metal particles injected into RF plasma torch were investigated according to their diameters ($1{\sim}100{\mu}m$), RF input power (6 ~ 12 kW) and the flow rates of carrier gases (2 and 5 slpm). From the numerical results, it is predicted firstly that the velocities of carrier gases need to be minimized because the strong injection of carrier gas can cool down the central column of RF thermal plasma significantly, which is used as a main path for RF thermal plasma treatment of micro-sized Ni metal. In addition, the residence time of the injected particles in the high temperature region of RF thermal plasma is found to be also reduced in proportion to the flow rate of the carrier gas In spite of these effects of carrier gas velocities, however, calculation results show that a Ni metal particle even with the diameter of $100{\mu}m$ can be completely evaporated at relatively low power level of 10 kW during its flight of RF thermal plasma torch (< 10 ms) due to the relatively low melting point and high thermal conductivity. Based on these observations, nano-sized Ni metal powders are expected to be produced efficiently by a simple treatment of micro-sized Ni metal using RF thermal plasmas.

• Textile Coloration and Finishing
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• v.24 no.4
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• pp.313-320
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• 2012

For the preparation of hardened films which can be applied as a binder for flame-resistant materials such as silica, linseed oil was subjected to a low temperature plasma treatment with argon, or oxygen gas. The film was produced much faster than so-called drying of oil in air. The SEM analysis for silica particles embedded in the hardened film after plasma treatment showed that the silica particles were immobilized on substrate and were evenly dispersed. The FT-IR spectral analysis for the plasma-treated linseed oil films demonstrated that the radicals which were formed during the plasma treatments caused the linseed oil to be cross-linked, and the plasmas attacked carbon chains of the oil randomly without focusing on specific vulnerable bonds such carbon double and carbonyl bonds intensively unless exposure times of the plasmas were prolonged too much, while the cross-linking of the air-dried film was considered to occur at the well-known typical sites, i.e., carbon-carbon double bond and ${\alpha}$-methylene carbon. Burning times, as a measure of flame/fire resistance, of silica-filled cellulose substrates, increased with increasing contents of silica.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1492-1494
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• 1996

We have studied the generation, growth and behavior of chemical species and particles in silane PCVD. We included the plasma chemistry of silane, particle nucleation by homogeneous formation, acrosol dynamics and transport phenomena of chemical species and particles. The concentration profile of chemical species and particles were shown as a function of reactor length. The effects of process variables such as reactor pressure, total gas flow rate and electrical field strength on the behavior of chemical species and particles were analyzed.

• Journal of the Semiconductor & Display Technology
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• v.22 no.3
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• pp.130-135
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• 2023

Plasma-resistant ceramic (PRC) is a material used to prevent internal damage in plasma processing equipment for semiconductors and displays. The challenge is to suppress particles falling off from damaged surfaces and increase retention time in order to improve productivity and introduce the latest miniaturization process. Here, we confirmed the effect of suppressing plasma deterioration and reducing the etch rate through surface treatment of existing PRC with an initial illumination level of 200 nm. In particular, quartz glass showed a decrease in etch rate of up to 10%. Furthermore, it is believed that micro-scale secondary particles formed on the microstructure of each material grow as crystals during the fluoridation process. This is a factor that can act as a killer defect when dropped, and is an essential consideration when analyzing plasma resistance. The plasma etching suppression effect of the initial illumination is thought to be due to partial over etching at the dihedral angle of the material due to the sputtering of re-emission of Ar+-based cations. This means that plasma damage due to densification can also be interpreted in existing PRC studies. The research results are significant in that they present surface treatment conditions that can be directly applied to existing PRC for mass production and a new perspective to analyze plasma resistance in addition to simple etching rates.

• Applied Science and Convergence Technology
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• v.27 no.1
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• pp.9-13
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• 2018

Samples of anodic oxide film used in semiconductor and display manufacturing processes were prepared at different electrolyte temperatures to investigate the corrosion resistance. The anodic oxide film was grown on aluminum alloy 6061 by using a sulfuric acid ($H_2SO_4$) electrolyte of 1.5 M at $0^{\circ}C$, $5^{\circ}C$, $10^{\circ}C$, $15^{\circ}C$, and $20^{\circ}C$. The insulating properties of the samples were evaluated by measuring the breakdown voltage, which gradually increased from 0.43 kV ($0^{\circ}C$) to 0.52 kV ($5^{\circ}C$), 1.02 kV ($10^{\circ}C$), and 1.46 kV ($15^{\circ}C$) as the electrolyte temperature was increased from $0^{\circ}C$ to $15^{\circ}C$, but then decreased to 1.24 kV ($20^{\circ}C$). To evaluate the erosion of the film by fluorine plasma, the plasma erosion and the contamination particles were measured. The plasma erosion was evaluated by measuring the breakdown voltage after exposing the film to $CF_4/O_2/Ar$ and $NF_3/O_2/Ar$ plasmas. With exposure to $CF_4/O_2/Ar$ plasma, the breakdown voltage of the film slightly decreased at $0^{\circ}C$, by 0.41 kV; however, the breakdown voltage significantly decreased at $20^{\circ}C$, by 0.83 kV. With exposure to $NF_3/O_2/Ar$ plasma, the breakdown voltage of the film slightly decreased at $0^{\circ}C$, by 0.38 kV; however, the breakdown voltage significantly decreased at $20^{\circ}C$, by 0. 77 kV. In addition, for the entire temperature range, the breakdown voltage decreased more when sample was exposed to $NF_3/O_2/Ar$ plasma than to $CF_4/O_2/Ar$ plasma. The decrease of the breakdown voltage was lower in the anodic oxide film samples that were grown slowly at lower temperatures. The rate of breakdown voltage decrease after exposure to fluorine plasma was highest at $20^{\circ}C$, indicating that the anodic oxide film was most vulnerable to erosion by fluorine plasma at that temperature. Contamination particles generated by exposure to the $CF_4/O_2/Ar$ and $NF_3/O_2/Ar$ plasmas were measured on a real-time basis. The number of contamination particles generated after the exposure to the respective plasmas was lower at $5^{\circ}C$ and higher at $0^{\circ}C$. In particular, for the entire temperature range, about five times more contamination particles were generated with exposure to $NF_3/O_2/Ar$ plasma than for exposure to $CF_4/O_2/Ar$ plasma. Observation of the surface of the anodic oxide film showed that the pore size and density of the non-treated film sample increased with the increase of the temperature. The change of the surface after exposure to fluorine plasma was greatest at $0^{\circ}C$. The generation of contamination particles by fluorine plasma exposure for the anodic oxide film prepared in the present study was different from that of previous aluminum anodic oxide films.

• Applied Science and Convergence Technology
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• v.27 no.1
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• pp.14-18
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• 2018

In order to understand the mechanism of the synthesis of particles using a plasma torch, it is necessary to understand the reaction mechanisms using a computer simulation. In this study, we have developed a simulation method to combine the Lagrangian scheme to follow microparticles and a nodal method to treat nanoparticles categorized with different particle sizes. The Lagrangian scheme includes the Coulomb force which affects the dynamics of larger particles. In contrast, the nodal method is adequate for the nanoparticles because the charge effect is negligible for nanoparticles but the number of nanoparticles is much larger than that of microparticles. This method is helpful to understand the dynamics and growth mechanism of micro- and nano-powder mixture observed in the experiment.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.77-77
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• 2012

As interest has increased in the interaction between low-temperature plasmas and materials, the role of modeling and simulation of processing in plasma has become important in understanding the effects of charged particles and radicals in plasma applications. Thus in this presentation, we present the theoretical and experimental studies of electron impact cross section for plasma processing gas, such as plasma etching and deposition processes. Also, here the work conducted at the Data Center for Plasma Properties (DCPP) over last 7 years on the systematic synthesis and assessment of fundamental knowledge on low-energy electron interactions with plasma processing gases is briefly summarized and discussed.