• 한국수소및신에너지학회논문집
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• 제18권2호
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• pp.132-139
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• 2007

Popular techniques for producing synthesis gas by converting methane include steam reforming and catalyst reforming. However, these are high temperature and high pressure processes limited by equipment, cost and difficulty of operation. Low temperature plasma is projected to be a technique that can be used to produce high concentration hydrogen from methane. It is suitable for miniaturization and for application in other technologies. In this research, the effect of changing each of the following variables was studied using an AC Glidarc system that was conceived by the research team: the gas components ratio, the gas flow rate, the catalyst reactor temperature and voltage. Glidarc plasma reformer was consisted of 3 electrodes and an AC power source. And air was added for the partial oxidation reaction of methane. The result showed that as the gas flow rate, the catalyst reactor temperature and the electric power increased, the methane conversion rate and the hydrogen concentration also increased. With $O_2/C$ ratio of 0.45, input flow rate of 4.9 l/min and power supply of 1 kW as the reference condition, the methane conversion rate, the high hydrogen selectivity and the reformer energy density were 69.2%, 36.2% and 35.2% respectively.

• 한국재료학회지
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• 제13권4호
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• pp.271-278
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• 2003

Conventional backlight for liquid crystal display (LCD) uses mercury which leads to environmental pollution. In this study, characteristics of AC coplanar type mercury-free plasma flat lamp have been studied. Pollution-free Xe-He is adopted as a discharge gas system. Since the Xe gas has a lower efficiency in generating vacuum ultraviolet (VUV) than mercury, the improvement of luminance and luminous efficiency in the Xe gas system is very important. The electrode, dielectric, and phosphor layers constituting lamp are formed on the bottom glass by the screen printing method. The effects of pulse shape, on-time, and pulse frequency on the luminance and luminous efficiency have been examined. For Xe(5%)-He gas, the lamp exhibits higher efficiency with sharper pulse shape, higher peak voltage, and shorter pulse on-time (up to 2 $\mu\textrm{s}$). Higher efficiency and lower consumption of power were obtained at 30 kHz than at 60 kHz. The collision of ion to bottom electrodes is a dominant factor to raise the lamp temperature. Therefore the high voltage and low current discharge system is necessary for reduction of the lamp temperature as well as for enhancement of the luminous efficiency.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 추계학술대회 논문집 전기물성,응용부문
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• pp.187-190
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• 2004

In this work, we investigated etching characteristics and mechanism of BST thin films using $Cl_2$/Ar, $CF_4/Cl_2$/Ar and $BCl_3/Cl_2$/Ar gas mixtures using inductively coupled plasma (ICP) system. A chemically assisted physical etch of BST was experimentally confirmed by ICP under various gas mixtures. The etch rate of the BST thin films had a maximum value at 20 $BCl_3$ and 10% $CF_4$ gas concentration, and decreased with further addition of $BCl_3$ or $CF_4$ gas, because $BaCl_x$, $SrCl_x$, $BaF_x$ and $SrF_x$ compounds have higher melting and boiling points. The maximum etch rate of the BST thin films was 57nm/min at the 30% $Cl_2(Cl_2+Ar)$. The characteristics of the plasma were analyzed by using OES and Langmuir probe.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.392-392
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• 2010

In this study, high-speed chemical dry thinning process of Si wafer and evolution of surface roughness were investigated. Direct injection of NO gas into the reactor during the supply of F radicals from $NF_3$ remote plasmas was very effective in increasing the Si thinning rate due to the NO-induced enhancement of surface reaction but thinned Si surface became roughened significantly. Addition of Ar gas, together with NO gas, decreased root mean square (RMS) surface roughness of thinned Si wafer significantly. The process regime for the thinning rate enhancement with reduced surface roughness was extended at higher Ar gas flow rate. Si wafer thinning rate as high as $22.8\;{\mu}m/min$ and root-mean-squared (RMS) surface roughness as small as 0.75 nm could be obtained. It is expected that high-speed chemical dry thinning process has possibility of application to ultra-thin Si wafer thinning with no mechanical damage.

• 한국재료학회지
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• 제31권3호
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• pp.162-171
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• 2021

Dry etching of copper thin films is performed using high density plasma of ethylenediamine (EDA)/hexafluoroisopropanol (HFIP)/Ar gas mixture. The etch rates, etch selectivities and etch profiles of the copper thin films are improved by adding HFIP to EDA/Ar gas. As the EDA/HFIP concentration in EDA/HFIP/Ar increases, the etch rate of copper thin films decreases, whereas the etch profile is improved. In the EDA/HFIP/Ar gas mixture, the optimal ratio of EDA to HFIP is investigated. In addition, the etch parameters including ICP source power, dc-bias voltage, process pressure are varied to examine the etch characteristics. Optical emission spectroscopy results show that among all species, [CH], [CN] and [H] are the main species in the EDA/HFIP/Ar plasma. The X-ray photoelectron spectroscopy results indicate the formation of CuCN compound and C-N-H-containing polymers during the etching process, leading to a good etch profile. Finally, anisotropic etch profiles of the copper thin films patterned with 150 nm scale are obtained in EDA/HFIP/Ar gas mixture.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1998년도 춘계학술발표회논문집(2)
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• pp.216-221
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• 1998

A study on induction plasma deposition with ceramic materials, yttria-stabilized-zirconia ZrO$_2$-Y$_2$O$_3$ (m.p 264O $^{\circ}C$), was conducted with a view developing a new method for nuclear fuel fabrication Before making dense pellets more than 96％TD., the spraying condition was optimized through the process parameters, such as chamber pressure, plasma plate power powder spraying distance, sheath gas composition, probe position, particle size and powders different morphology. The results with a 5mm thick deposit on rectangular planar graphite substrates showed a 97.11％ theoretical density when the sheath gas flow rate was Ar/H$_2$120/20 l/min, probe position 8cm, particle size -75 ${\mu}{\textrm}{m}$ and spraying distance 22cm by AMDRY146 powder. The degree of influence of the main effects on density were powder morphology. particle size, sheath gas composition, plate power and spraying distance, in that order. Among the two parameter interactions, the sheath gas composition and chamber pressure affects density greatly. By using the multi-pellets mold wheel type, the pellet density did not exceed 94%T.D., owing to the spraying angle.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.515-517
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• 2004

The laser absorption spectroscopy has been used for measuresurement of the xenon atoms in the resonant $1S_4$ and metastable $1S_5$ states in coplanar AC PDP. For the purpose of improving VUV luminous efficiency and optimization of PDP cells, it is important to study behavior of excited Xe atoms in a micro-discharge cell of a coplanar AC-PDP. We measured the xenon excited density of $1S_5$ and $1S_4$ state under mixture gas of Ne-Xe(10%) with gas pressure of 350 Torr and sustaining gap distance of 150 um.

• 한국전기전자재료학회논문지
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• 제31권3호
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• pp.156-159
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• 2018

Inductively coupled plasma (ICP) treatment with argon and a mixture of argon and oxygen gases has been used to modify the surface of polycarbonate (PC) substrates. The results showed that the surface contact angle was inversely proportional to the plasma discharge power and that the mixed-gas plasma (gas flow 10:10 sccm, discharge power 60 W) decreased the surface contact angle as low as $18.3^{\circ}$, indicating a large increase in the surface hydrophilicity. In addition, $SnO_2$ thin films deposited on the PC substrate effectively enhanced the ICP plasma treatment, and could also enhance the usefulness of PC in the inner parts of automobiles.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1533_1534
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• 2009

This paper presents an atmospheric micro glow plasma-jet device. The device consists of four components; a thin Ni anode, a porous alumina insulater, a stainless steel cathode and an aluminum case. The Ni anode is fabricated using micromachining technology. The anode has 10 holes, of which the hole diameter and the depth are $250{\mu}m$ and $60{\mu}m$, respectively. The discharge test is performed in nitrogen gas at atmospheric pressure for 20 kHz AC bias. The breakdown voltage is 3.5 kV at gas flow rate of 4 L/min and the the plasma-jet is blown out to ambient at 5.5 kV. In order to verify the characteristics of plasma, the current and the voltage of device are measured. The maximum temperature of plasma is $37^{\circ}C$. The plasma is well generated and stable at high voltage.

• Journal of Advanced Marine Engineering and Technology
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• 제32권2호
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• pp.262-267
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• 2008

Plasma immersion ion beam (PIIB) nitriding process is an environmentally benign and cost-effective process, and offers the potential of producing high dose of nitrogen ions in a way of simple, fast and economic technique for the high plasma flux treatment of large surface area with nitrogen ion source gas. In this report PIIB nitriding technique was used for nitriding on austenite stainless steel of AISI304 with plasma treatment at $250{\sim}500^{\circ}C$ for 4 hours, and with the working gas pressure of $2.67{\times}10^{-1}$ Pa in vacuum condition. This PIIB process might prove the advantage of the low energy high flux of ion bombardment and enhance the tribological or mechanical properties of austenite stainless steel by nitriding, Furthermore, PIIB showed a useful surface modification technique for the nitriding an irregularly shaped three dimensional workpiece of austenite stainless steel and for the improvement of surface properties of AISI 304, such as hardness and strength