• Membrane Journal
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• v.13 no.2
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• pp.73-80
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• 2003

Abstract: The surfaces of poly (methylpentene)(PMP) were modified by Af and $NH_3$ plasma treatment, and their effects on permeation characteristics were investigated. The mole ratio of O/C in the surface was increased with Ar plasma treatment and consequently the surface became hydrophilic because of the possible formation of -OH, -COOH and C=O. The surface treated by $NH_3$ plasma also became hydrophilic due to the formation of amine and/or amide groups. The $CO_2$ permeability and its actual selectivity over N_2$ were 182 baller and 6.17 for the optimum condition of Ar-30W-6min, while 144 Baller and 6.13 for that of $NH_3$-30 W-8 min.

• Journal of the Korean institute of surface engineering
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• v.48 no.6
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• pp.269-274
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• 2015

In this experiment, post-nitriding treatment was performed at $400^{\circ}C$ on AISI 316 stainless steel which was plasma carburized previously at $430^{\circ}C$ for 15 hours. Plasma nitriding was implemented on AISI 316 stainless steel at various gas compositions (25% $N_2$, 50% $N_2$ and 75% $N_2$) for 4 hours. Additionally, during post nitriding Ar gas was used with $H_2$ and $N_2$ to observe the improvement of surface properties. After treatment, the behavior of the hybrid layer was investigated by optical microscopy, X-ray diffraction, and micro-hardness testing. Potentiodynamic polarization test was also used to evaluate the corrosion resistance of the samples. Meanwhile, it was found that the surface hardness increased with increasing the nitrogen gas content. Also small percentage of Ar gas was introduced in the post nitriding process which improved the hardness of the hardened layer but reduced the corrosion resistance compared with the carburized sample. The experiment revealed that AISI 316L stainless steel showed better hardness and excellent corrosion resistance compared with the carburized sample, when 75% $N_2$ gas was used during the post nitriding treatment. Also addition of Ar gas during post nitriding treatment degraded the corrosion resistance of the sample compared with the carburized sample.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.912-916
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• 2002

In this paper, the $CF_4$ decomposition rate and by-product were investigated for a simulated two plasma reactors which are metal particle reactor and spiral wire reactor as function of mixed gases. The $CF_4$ decomposition rate by plasma reactor with metal particle electrode had a gain of 20~25[%] over that by plasma reactor with spiral wire electrode. The $CF_4$ decomposition efficiency increases with increasing applied voltage up to the critical voltage for spark formation. The $CF_4$ decomposition efficiency of metal particle reactor was about 80[%] at AC 24[kV]. The $CF_4$ decomposition rate used $Ar-N_2$ as base gas was the highest among three base gases of $N_2$, $Ar-N_2$, air. The by-products of the $N_2$, $Ar-N_2$ base as were similar, but in case of air base they were different.

• Korean Chemical Engineering Research
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• v.40 no.6
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• pp.687-693
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• 2002

The surface of polyethersulfone(PES) membrane treated by Ar, $NH_3$ plasma, and the effects were observed before and after the treatment. The membrane treated by Ar plasma was increased the O/C ratio and measured the hydrophilic group, and the one by $NH_3$ plasma was attached the amine group and the amino group. In addition, with the wettability of polyethersulfone membrane $CO_2$ and the polar functional groups of surface interacted increasingly. Thus by comparable increase of the soluble selectivity $CO_2$ to $N_2$ both the permeability and the selectivity of $CO_2$ was improved. The optimum condition for the $CO_2$ permeation and actual separation factor of the plasma treated membrane was as follows; the measurement of Ar-10 W-2 min plasma treatment was $13.19{\times}10^{-10}cm^3(STP)cm/cm^2{\cdot}s{\cdot}cmHg$ and 20.12, and the measurement of $NH_3$-50 W-2 min plasma treatment was $15.40{\times}10^{-10}cm^3(STP)cm/cm^2{\cdot}s{\cdot}cmHg$ and 20.06.

• Journal of environmental and Sanitary engineering
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• v.13 no.2
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• pp.147-155
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• 1998

In this study, we prepared non-porous plasma membrane for having high permeability and selectivity and this membrane was deposited on the $Al_{2}O_{3}$ membrane by using $CHF_{3}$ & $SiH_{4}$ monomer. Also, we investigated for the permeation characteristics of the plasma polymer membrane by Ar plasma treatment. When the position of substrate was near cathode, the selectivity was increased with Ar plasma treatment time and rf-power. The pore size of $Al_{2}O_{3}$ membrane had an effect on the permeability and the position of substrate affected selectivity.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.4
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• pp.203-209
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• 2000

This paper proposes the improvement of the etch rate of GaN using a magnetized inductively coupled $CH_4/H_2/Ar$plasma. The gradient magnetic field with the axial direction is investigated using Gauss-meter and the ion current density is measured using double Langmuir probe. The applied magnetic field changes the ion current density profile in the radial direction, resulting in producing the higher density in the outer region than in the center. GaN dry etching process is carried out based on the measurements of the ion current density. The each rate of 2000 /min is achieved with $CH_4/H_2/Ar$ chemistries at 800 W input power, 250W rf bias power, 10 mTorr pressure and 100 gauss magnetic field.

• Journal of the Korean institute of surface engineering
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• v.41 no.3
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• pp.83-87
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• 2008

This study described the effects of RF power, DC bias voltage, chamber pressure and gas mixing ratio on the etch rates of TiN thin film and selectivity of TiN thin film to $SiO_2$ with $BCl_3$/Ar gas mixture. When the gas mixing ratio was $BCl_3$(20%)/Ar(80%) with other conditions were fixed, the maximum etch rate of TiN thin film was 170.6 nm/min. When the DC bias voltage increased from -50 V to -200 V, the etch rate of TiN thin film increased from 15 nm/min to 452 nm/min. As the RF power increased and chamber pressure decreased, the etch rate of TiN thin film showed an increasing tendency. When the gas mixing ratio was $BCl_3$(20%)/Ar(80%) under others conditions were fixed, the intensity of optical emission spectra from radical or ion such as Ar(750.4 nm), $Cl^+$(481.9 nm) and $Cl^{2+}$(460.8 nm) was highest. The TiN thin film was effectively removed by the chemically assisted physical etching in $BCl_3$/Ar ICP plasma.

• Transactions on Electrical and Electronic Materials
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• v.14 no.2
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• pp.67-70
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• 2013

In this study, we changed the input parameters (gas mixing ratio, RF power, DC bias voltage, and process pressure), and then monitored the effect on TiN etch rate and selectivity with $SiO_2$. When the RF power, DC-bias voltage, and process pressure were fixed at 700 W, - 150 V, and 15 mTorr, the etch rate of TiN increased with increasing $CF_4$ content from 0 to 20 % in $CF_4$/Ar plasma. The TiN etch rate reached maximum at 20% $CF_4$ addition. As RF power, DC bias voltage, and process pressure increased, all ranges of etch rates for TiN thin films showed increasing trends. The analysis of x-ray photoelectron spectroscopy (XPS) was carried out to investigate the chemical reactions between the surfaces of TiN and etch species. Based on experimental data, ion-assisted chemical etching was proposed as the main etch mechanism for TiN thin films in $CF_4$/Ar plasma.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.05a
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• pp.177-178
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• 2012

In this experiment, post-nitriding treatment has been performed at $400^{\circ}C$ on AISI 316 stainless steel which is plasma carburized previously at $430^{\circ}C$ for 15 hours. Plasma nitriding was implemented on AISI 316 stainless steel at various gas compositions (25% N2, 50% N2 and 75% N2) for 4 hours. Additionally, during post nitriding Ar gas was used with H2 and N2 to observe the improvement of treatment. After treatment, the behavior of the hybrid layer was investigated by optical microscopy, X-ray diffraction, and micro-hardness testing. Potentiodynamic polarization test was also used to evaluate the corrosion resistance of the samples. Meanwhile, it was found that the surface hardness increased with increasing the nitrogen gas content. Also small percentage of Ar gas was introduced in the post nitriding process which improved the hardness of the hardened layer but reduces the corrosion resistance compared with the carburized sample. The experiment revealed that AISI 316L stainless steel showed better hardness and excellent corrosion resistance compared with the carburized sample, when 75% N2 gas was used during the post nitriding treatment. Also addition of Ar gas during post nitriding treatment were degraded the corrosion resistance of the sample compared with the carburized sample.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2006.04a
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• pp.134-134
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• 2006