• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.202-202
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• 1999

The Polyethylene (PE), Polystyrene (PS) and Polytetrafluoroethylene (PTFE) surface modification was investigated by hydrogen io assisted reaction (H-IAR) in oxygen environment. The IAR is a kind of surface modification techniques using ion beam irradiation in reactive gas environment. The energy of hydrogen ion beam was fixed at 1keV, io dose was varied from 5$\times$1014 to 1$\times$1017 ions/$\textrm{cm}^2$, and amount of oxygen blowing gas was fixed 4ml/min. Wettability was measured by water contact angles measurement, and the surface functionality was analyzed by x-ray photoelectron spectroscopy. The contact angle of water on PE modified by argon ion beam only decrease from 95$^{\circ}$ to 52$^{\circ}$, and surface energy was not changed significantly. But, the contact angle using hydrogen ion beam with flowing 4ml/min oxygen stiffly decreased to 8$^{\circ}$ and surface energy to 65 ergs/cm. In case of PS, the contact angle and surface energy changes were similar results of PE, but the contact angle of PTEE samples decreased with ion dose up to 1$\times$1015 ions/$\textrm{cm}^2$, increased at higher dose, and finally increased to the extent that no wetting was appeared at 1$\times$1017 ions/$\textrm{cm}^2$. These results must be due to the hydrogen ion beam that cleans the surface removing the impurities on polymer surfaces, then hydrogen ion beam was activated with C-H bonding to make some functional groups in order to react with the oxygen gases. Finally, unstable polymer surface can be changed from hydrophobic to hydrophilic formation such as C-O and C=O that were confirmed by the XPS analysis, conclusionally, the ion assisted reaction is very effective tools to attach reactive ion species to form functional groups on C-C bond chains of PE, PS and PTFE.

• Korean Journal of Materials Research
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• v.15 no.6
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• pp.382-387
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• 2005

Polyvinylidene fluoride (PVDF) surface was irradiated and became superhydrophilic by low energy (180 eV) and high flux $(\~10^{15}/cm{\cdot}s)$ ion beam. As an ion source, a closed electron Hall drift thruster of $\phi=70mm$ outer channel size without grid was adopted. Ar, $O_2$ and $N_2O$ were used for source gases. When $N_2O^+$ and $O_2^+$ reactive gas ion beam were irradiated with the ion fluence of $5\times10^{15}/cm^2$, the wetting angle for deionized water was drastically dropped from $61^{\circ}\;to\;4^{\circ}\;and\;2^{\circ}$, respectively. Surface energy was also increased up to from 44 mN/m to 81 mN/m. Change of chemical component in PVDF surface was analyzed by x-ray photoelectron spectroscopy. Such a great increase of the surface energy was intimately related with the increase of hydrophilic group component in reactive ion irradiated PVDF surfaces. By using an atomic force microscopy, the root-mean-square of surface roughness of ion irradiated PVDF was not much altered compared to that of pristine PVDF.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.30 no.2
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• pp.196-204
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• 2020

Objective: Chronic obstructive pulmonary disease(COPD) is characterized by persistent airflow limitations associated with chronic inflammatory response due to noxious particles or gases in the lung. Increasing oxidative stress associated with COPD. The aim of this study was to evaluate the influencing factors of biomarkers for oxidative stress in retired miners with COPD. Methods: The levels of total peroxide(TPx), total antioxidant capacity(TAC), and oxidative stress index(TPx/TAC ratio, OSI) in plasma as biomarkers for oxidative stress, serum C-reactive protein(CRP) as a biomarker for inflammation, and general characteristics were measured in 93 male subjects with COPD. COPD was defined as post bronchodilator FEV₁/FVC<0.7 by spirometry. Results: Mean levels of TPx(p=0.013), TAC(p=0.010), OSI(p=0.040), and CRP(p=0.024) were higher in current smokers. Levels of TPx(β=0.445, p<0.001), TAC(β=0.490, p<0.001), and OSI(β=0.351, p<0.001) were related to CRP levels, and CRP levels were related to %FEV₁ predicted(β=-0.295, p=0.003) and current smoking(β=0.214, p=0.032). Conclusions: These results suggest that oxidative stress was related to inflammation, and inflammation were related to decreasing %FEV₁ predicted and current smoking in retired miners with COPD.

• Journal of the Korean institute of surface engineering
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• v.37 no.6
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• pp.307-312
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• 2004

Extensive efforts have been made in an attempt to utilize photocatalytic properties of $TiO_2$ in visible range. $TiO_2$ and TiO-N thin films were made by the DC reactive magnetron sputtering method at $300^{\circ}C$. Various gases (Ar, $O_2$ and $N_2$) were used and Ti target was impressed by 0.6 kW-5.8 kW power range. The hysteresis phenomenon of the $TiO_2$ thin film as a function of the discharge voltage characteristic was observed to be higher as applied power increases. That of TiO-N thin film was occurred at the 5.8 kW power. The cross section and surface roughness of thin films were observed by FE-SEM and AFM. Average surface roughness of TiO-N thin film was observed as $15.9\AA$ and that of $TiO_2$ as $13.2\AA$. The crystal phases of both $TiO_2$ and TiO-N thin films were found to be anatase structure. The atomic $\beta$-N (396 eV peak in N 1s XPS) was shown in the rutile crystal of TiO-N and was considered acting as the origin of wavelength shift to the visible light.

• Journal of the Microelectronics and Packaging Society
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• v.3 no.1
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• pp.11-24
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• 1996

부분압이 다른 여러 가지 반응성 가스분위기하에서 이른곤 이온을 이용하여 PC, PET PMMA 그리고 PTFE 폴리머 표면의 삼차 증류수에대한 진수성을 증대하였다. 폴리머 표면의 친수성의 변화는 여러 가지 반응성 가스 분위기하에서 아르곤 이온의 조사량을 1014 부터 1x1017cm2까지 변화하면서 조사하였다. 접촉감은 아르곤 이온이 조사되는 폴리머 표면 근처에 유입된 가스의 방응성(O2>N2>H2)에 따라 많이 감소하였다, 폴리머 표면에 형성된 친수성기는 XPS Cls, Ols, 그리고 Nls 스펙트럼을 분석하여 확인하였다. 표면 개질된 PC와 PTFE에 대한 Al 금속의 접착력 증대를 Scotch tape와 인장실험을 통하여 확인하였다. 접착 력 증가는 표면 에너지 중 polar force의 증가에 의한 것으로 입증되었다. 에너지를 가진 아 르곤 입자 폴리머 체인 그리고 반응성 가스 사이의 반응기구는 2단계 모델로 설명가능하였 는데 그 기구는 첫 번째 이온의 조사에 의한 불안정한 폴리머 체인의 형성과 두 번째 단계 로 이렇게 형성된 폴리머 체인과 반응성 가스들 사이의 화학반응으로 이루어진다. 질화아루 미늄의 표면을 산소분위기하에서 아르곤 빔을 조사하여 표면개질한후 AlON층이 새롭게 형 성된 것을 XPS를 이용하여 확인할수 있었다. 개질된 질화알루미늄과 구리금속 박막간의 접 착력을 scratch 실험을 통하여 조사하였다.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.239-239
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• 2003

As a result of the recent miniaturization and enhancement in the performance of thin film inductors and thin film transformers, there are increased demands for the thin films with a high magnetic permeability in the high frequency range, a high saturation magnetization, a high electrical resistivity, and a low coercive force. In order to improve high frequency properties, we will investigate anisotropy field by shape and size of pattern. The Fe-Al-O thin films of 16mm diameter and 1$\mu\textrm{m}$ thickness were deposited on Si wafer, using RE magnetron reactive sputtering technique with the mixture of argon and oxygen gases. The fabricating conditions are obtained in the working partial pressure of 2m Torr, O$_2$ partial Pressure of 5%, Input power of 400w, and Al pellets on an Fe disk with purity of 99.9%. For continuous thin film is the 4Ms of 19.4kG, H$\sub$c/ of 0.6Oe, H$\sub$k/ of 6.0Oe and effective permeability of 2500 up to 100MHz. In this work, we expect to enhanced effect of magnetic anisotropy on patterned of Fe-Al-O thin films.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.338-341
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• 1995

The surface properties after plasma etching of Al(Si, Cu) solutions using the chemistries of chlorinated and fluorinated gases with varying the etching time have been investigated using X-ray Photoelectron Spectroscopy. Impurities of C, Cl, F and O etc are observed on the etched Al(Si, Cu) films. After 95% etching, aluminum and silicon show metallic states and oxized (partially chlorinated) states, copper shows Cu metallic states and Cu-Clx(x$CuCl_x$ (x$CuCl_x$ (1

• Journal of Powder Materials
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• v.20 no.6
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• pp.411-424
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• 2013

In this study, the synthesis of nickel nanoparticles and copper nanospheres for the potential applications of MLCC electrode materials has been studied by plasma arc evaporation method. The change in the broad distribution of the size of nickel and copper nanopowders is successfully controlled by manifesting proper mixture of gas ambiance for plasma generation in the size range of 20 to 200 nm in diameter. The factors affecting the mean diameter of the nanopowder was studied by changing the composition of reactive gases, indicating that nitrogen enhances the formation of larger particles compared to hydrogen gas. The morphologies and particle sizes of the metal nanoparticles were observed by SEM, and ultrathin oxide layers on the powder surface generated during passivation step have been confirmed using TEM. The metallic FCC structure of the nanoparticles was confirmed using powder X-ray diffraction method.

• Journal of the Korean institute of surface engineering
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• v.39 no.3
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• pp.98-104
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• 2006

Al-doped ZnO (AZO) films were deposited on the plastic substrate by inductively coupled plasma (ICP) assisted DC magnetron sputtering. The AZO films were produced by sputtering a metallic target (Zn/Al) in a mixture of argon and oxygen gases. AZO films with an electrical resistivity of ${\sim}10^3\;{\Omega}cm$ and an optical transmittance of 80% were obtained even at a low deposition temperature. In-situ process control methods were used to obtain stable deposition conditions in the transition region without any hysteresis effect. The target voltage was controlled either at a constant DC power. It was found that the ratio of the zinc to oxygen emission intensity, I (O 777)/I (Zn 481) decreased with increasing the target voltage in the transition region. The $Ar/O_2$ plasma treatment improve the adhesion strength between the polycarbonate substrate and AZO films.

• JSTS:Journal of Semiconductor Technology and Science
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• v.8 no.3
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• pp.244-250
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• 2008

An inductively coupled plasma etching process to replace an existing slower rate reactive ion etching process for $60{\mu}m$ diameter via-holes using Cl2/BCl3 gases has been investigated. Process pressure and platen power were varied at a constant ICP coil power to reproduce the RIE etched $200{\mu}m$ deep via profile, at high etch rate. Desired etch profile was obtained at 40 m Torr pressure, 950 W coil power, 90W platen power with an etch rate ${\sim}4{\mu}m$/min and via etch yield >90% over a 3-inch wafer, using $24{\mu}m$ thick photoresist mask. The etch uniformity and reproducibility obtained for the process were better than 4%. The metallized via-hole dc resistance measured was ${\sim}0.5{\Omega}$ and via inductance value measured was $\sim$83 pH.