• Journal of the Semiconductor & Display Technology
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• v.7 no.2
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• pp.35-38
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• 2008

This study shows the improvement of PR-Ashing rates in semi-conductor process using Atmospheric Plasma. Taguchi method is used to improve Ashing rates of photo-resist that is spread on the surface of a wafer. Improvement of Ashing rates is acquired through the decision of the effective factors and suitable combination of the factors. The results show the contribution rate of each factor and the effectiveness of Plasma for PR-Ashing process in this system.

• Journal of Industrial and Engineering Chemistry
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• v.68
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• pp.372-379
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• 2018

The improvement of $NO_x$ reduction by $Ag/{\gamma}-Al_2O_3$ with a hydrocarbon ($n-C_7H_6$) in the early state was investigated in a packed-bed dielectric barrier discharge plasma reactor. The results revealed that the combination of plasma with the catalyst enhanced $NO_x$ reduction efficiency at low operating temperatures, depending on the temperature and specific input energy. To sum up, the poor performance of the catalytic $NO_x$ reduction at low temperatures in the early stage before reaching thermochemical steady state can be greatly compensated for by using the atmospheric-pressure plasma generated in the catalyst bed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.2
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• pp.148-152
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• 2005

Atmospheric low-temperature plasma was produced using dielectric barrier discharge (DBD) plate-type plasma reactor and high frequency of 13.56 Hz. The surfaces of polyimide films for insulating and packaging materials were treated by the atmospheric low-temperature plasma. The contact angle of 67$^{\circ}$ was observed before the plasma treatment. The contact angle was decreased with deceasing the velocity of plasma treatment. In case of oxygen content of 0.2 %, electrode gap of 2 mm, the velocity of plasma treatment of 20 mm/sec, and input power of 400 W, the minimum contact angle of 13$^{\circ}$ was observed. The chemical characteristics of polyimide film after the plama treatment were investigated using X-ray photoelectron spectroscopy (XPS), and new carboxyl group bond was observed. The surfaces of polyimide films were changed into hydrophilic by the atmospheric low-temperature plasma. The polyimide films having hydrophilic surface will be very useful as a packaging and insulating materials in electronic devices.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.7
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• pp.459-466
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• 2012

In order to improved treatment performance of dielectric barrier discharge (DBD) plasma, plasm + UV process and gas-liquid mixing method has been investigated. This study investigated the degradation of N, N-Dimethyl-4-nitrosoaniline (RNO, indicator of the generation of OH radical). The basic DBD plasma reactor of this study consisted of a plasma reactor (consist of quartz dielectric tube, titanium discharge (inner) and ground (outer) electrode), air and power supply system. Improvement of plasma reactor was done by the combined basic plasma reactor with the UV process, adapt of gas-liquid mixer. The effect of UV power of plasma + UV process (0~10 W), gas-liquid mixing existence and type of mixer, air flow rate (1~6 L/min), range of diffuser pore size (16~$160{\mu}m$), water circulation rate (2.8~9.4 L/min) and UV power of improved plasma + UV process (0~10 W) were evaluated. The experimental results showed that RNO degradation of optimum plasma + UV process was 7.36% higher than that of the basic plasma reactor. It was observed that the RNO decomposition of gas-liquid mixing method was higher than that of the plasma + UV process. Performance for RNO degradation with gas-liquid mixing method lie in: gas-liquid mixing type > pump type > basic reactor. RNO degradation of improved reactor which is adapted gas-liquid mixer of diffuser type showed increase of 17.42% removal efficiency. The optimum air flow rate, range of diffuser pore size and water circulation rate for the RNO degradation at improved reactor system were 4 L/min, 40~$100{\mu}m$ and 6.9 L/min, respectively. Synergistic effect of gas-liquid mixing plasma + UV process was found to be insignificant.

• Journal of the Korean Vacuum Society
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• v.19 no.1
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• pp.22-27
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• 2010

To improve surface wettability, each sample was treated by atmospheric pressure plasma (APP) using dielectric barrier discharge (DBD) system. Argon and oxygen gases were used for treatment gas to modify the $TiO_2$ surface by APP with RF power range from 50 to 200 W. Water contact angle was decreased from $20^{\circ}$ to $10^{\circ}$ with argon only. However, water contact angle was decreased from $20^{\circ}$ to < $1^{\circ}$ with mixture of argon and oxygen. Water contact angle with $O_2$ plasma was lower than water contact angle with Ar plasma at the same RF power. It seems to be increasing the polar force of $TiO_2$ surface. Also, analysis result of X-ray photoelectron spectra (XPS) shows the increase of intensity of O1s shoulder peak, resulting in increasing of surface wettability by APP. Moreover, each water contact angle increased according to increase past time. However, contact angle increase with plasma treatment was lower than without plasma treatment. Additionally, the efficiency of $TiO_2$ photocatalyst was improved by plasma surface-treatment through the degradation experiment of phenol.

• Journal of Environmental Science International
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• v.24 no.11
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• pp.1393-1404
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• 2015

Ten empirical disinfection models for the plasma process were used to find an optimum model. The variation of model parameters in each model according to the operating conditions (first voltage, second voltage, air flow rate, pH, incubation water concentration) were investigated in order to explain the disinfection model. In this experiment, the DBD (dielectric barrier discharge) plasma reactor was used to inactivate Phytophthora capsici which cause wilt in tomato plantation. Optimum disinfection models were chosen among ten models by the application of statistical SSE (sum of squared error), RMSE (root mean sum of squared error), $r^2$ values on the experimental data using the GInaFiT software in Microsoft Excel. The optimum models were shown as Log-linear+Tail model, Double Weibull model and Biphasic model. Three models were applied to the experimental data according to the variation of the operating conditions. In Log-linear+Tail model, $Log_{10}(N_o)$, $Log_{10}(N_{res})$ and $k_{max}$ values were examined. In Double Weibull model, $Log_{10}(N_o)$, $Log_{10}(N_{res})$, ${\alpha}$, ${\delta}_1$, ${\delta}_2$, p values were calculated and examined. In Biphasic model, $Log_{10}(N_o)$, f, $k_{max1}$ and $k_{max2}$ values were used. The appropriate model parameters for the calculation of optimum operating conditions were $k_{max}$, ${\alpha}$, $k_{max1}$ at each model, respectively.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.96-96
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• 2010

To improve surface wettability, each sample was treated by atmospheric pressure plasma (APP) using dielectric barrier discharge (DBD) system. Argon and oxygen gases were used for treatment gas to modify the $TiO_2$ surface by APP with RF power range from 50 to 200 W. Water contact angle was decreased from $20^{\circ}$ to $10^{\circ}$ with argon only. However, water contact angle was decreased from $20^{\circ}$ to < $1^{\circ}$ with mixture of argon and oxygen. Water contact angle with $O_2$ plasma was lower than water contact angle with Ar plasma at the same RF power. It seems to be increasing the polar force of $TiO_2$ surface. Also, analysis result of X-ray photoelectron spectra (XPS) shows the increase of intensity of O1s shoulder peak, resulting in increasing of surface wettability by APP. Moreover, each water contact angle increased according to increase past time. However, contact angle increase with plasma treatment was lower than without plasma treatment. Additionally, the efficiency of $TiO_2$ photocatalyst was improved by plasma surface-treatment through the degradation experiment of phenol

• Journal of the Korean Institute of Gas
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• v.22 no.1
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• pp.26-36
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• 2018

Conventional nickel-based catalyst processes used for dry reforming reactions have high activation temperatures and problems such as carbon deposition and metal sintering on the active sites of the catalyst surface. In this study, the characteristics of butane dry reforming reaction were investigated by using DBD plasma combined with catalytic process and compared with existing catalyst alone process. The physical and chemical properties of the catalysts were investigated using a surface area & pore size analyzer, XRD, SEM and TEM. Using $10%Ni/{\gamma}-Al_2O_3$ at $580^{\circ}C$, in the case of the catalyst+plasma process, the conversion of carbon dioxide and butane were improved by about 30% than catalyst alone process. When the catalyst+plasma process, the conversion of carbon dioxide and butane and the hydrogen production concentration are enhanced by the influence of various active species generated by the plasma. In addition, it was found that the particle size of the catalyst is decreased by the plasma in the reaction process, and the degree of dispersion of the catalyst is increased to improve the efficiency.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.540-541
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• 2005

• Journal of Environmental Science International
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• v.22 no.7
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• pp.915-923
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• 2013

Decomposition of non-biodegradable contaminants such as phenol contained in water was investigated using a dielectric barrier discharge (DBD) plasma reactor in the aqueous solutions with continuous oxygen bubbling. Effects of various parameters on the removal of phenol in aqueous solution with high-voltage streamer discharge plasma are studied. In order to choose plasma gas, gas of three types (argon, air, oxygen) were investigated. After the selection of gas, effects of 1st voltage (80 ~ 220 V), oxygen flow rate (2 ~ 7 L/min), pH (3 ~ 11), and initial phenol concentration (12.5 ~ 100.0 mg/L) on phenol degradation and change of $UV_{254}$ absorbance were investigated. Absorbance of $UV_{254}$ can be used as an indirect indicator of phenol degradation and the generation and disappearance of the non-biodegradable organic compounds. Removal of phenol and COD were found to follow pseudo first-order kinetics. The removal rate constants for phenol and COD of phenol were $5.204{\times}10^{-1}min^{-1}$ and $3.26{\times}10^{-2}min^{-1}$, respectively.