• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.231.1-231.1
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• 2015

Surface energy, being an important material parameter to control its interactions with the other surfaces plays a key role in bio-related application. Carbon films are found very promising due to their characteristics such as wear and corrosion resistant, high hardness, inert, low resistivity and biocompatibility. The present work deals with the deposition of carbon films using unbalanced facing target magnetron sputtering technique. The discharge characteristics were studied using optical emission spectroscopy and correlated with the film properties. Surface energy was investigated through contact angle measurement. The ID/IG ratio as calculated from Raman spectroscopy data increases with the increase in power density due to the higher number of sp2 clusters embedded in the amorphous matrix. The deposited films were smooth and homogeneous as observed by Atomic force microscopy having RMS roughness in the range of 1.74 to 2.25 nm. It is observed that electrical resistivity and surface energy varies in direct proportionality with operating pressure and has inverse relation with power density. The surface energy results clearly exhibited that these films can have promising applications in cell cultivation.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2007.04a
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• pp.139-140
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• 2007

본 연구에서는 ion bombardment에 의한 폴리머 기판의 손상을 줄이기 위해 FTS (Facing Target Sputtering) 장치를 이용하여 투명 전극용 ITO 박막을 합성하였다. 산소와 헬륨의 혼합비율을 변수로 하여 박막을 합성한 결과, 투명전극에 적합한 낮은 비저항과 80% 이상의 투과도를 갖는 박막을 합성할 수 있었다.

• Transactions on Electrical and Electronic Materials
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• v.5 no.3
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• pp.98-103
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• 2004

The plasma properties in the facing target sputtering system during carbon nitride film deposition have been investigated. The ionized nitrogen species of the deposited films increased with increasing discharge current and were independent of the nitrogen pressure. The nitrogen content in the films did not vary significantly with the variation of nitrogen gas. The electron temperature was high close to that in the inter-cathode region, reduced as the electrons moved away from the most intense region of magnetic confinement and increased again outside this region. Calculations based on the film composition showed that the ion to carbon atom ratio at the substrate was about 50 and that the ratio between the ionized and neutral nitrogen molecules was about 0.25.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.896-897
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• 2006

In the viewpoint of engineering, materials problem is a key problem, which determines whether the exploitation of fusion energy will be success. The most important class of fusion materials is plasma-facing materials (PFM). W, as high Z high melting-point metal is one of the most important candidate materials due to its high plasma erosion resistance. Improving the ductility of W and W based alloy, lowering its ductile-brittleness transition temperature for meeting the requirements of fusion application is an important task. In this paper, severalpowder meatllurgy methods of fabricating W and W based materials are being investigated.

• Journal of the Korean institute of surface engineering
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• v.41 no.5
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• pp.199-204
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• 2008

Indium tin oxide (ITO) has been commonly used as an anode for organic light emitting diode (OLED), because of its relatively high work function, high transmittance, and low resistance. The ITO was mostly deposited by capacitive type DC or RF sputtering. In this study we introduced a new facing target sputtering method. On applying this new sputtering method, the effect of fundamental deposition parameters such as substrate heating and post etching were investigated in relation to the resultant I-V-L characteristics of OLED. Three kinds of ITOs deposited at room temperature, at $400^{\circ}C$ and at $400^{\circ}C$ with after surface modification by $O_2$ plasma etching were compared. The OLED on ITO deposited with substrate heating and followed by etching showed better I-V-L characteristics, which starts to emit light at 4 volts and has luminescence of $65\;cd/m^2$ at 9 volts. The better I-V-L characteristics were ascribed to the relevant surface roughness with uniform micro-extrusions and to the equi-axed micromorphology of ITO surface.

• Journal of Information Display
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• v.8 no.3
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• pp.5-10
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• 2007

Twin target sputtering (TTS) system with a configuration of vertically parallel facing Al targets and a substrate holder perpendicular to the Al target plane has been designed to realize a direct Al cathode sputtering on organic light emitting diodes (OLEDs). The TTS system has a linear twin target gun with ladder type magnet array for effective and uniform confinement of high density plasma. It is shown that OLEDs with Al cathode deposited by the TTS show a relatvely lower leakage current density $({\sim}1{\times}10^{-5}mA/cm^2)$ at reverse bias of -6V, compared to that ($1{\times}10^{-2}{\sim}10^{-3}$ $mA/cm^2$ at -6V) of OLEDs with Al cathodes grown by conventional DC magnetron sputtering. In addition, it was found that Al cathode films prepared by TTS were amorphous structure with nanocrystallines due to low substrate temperature. This demonstrates that there is no plasma damage caused by the bombardment of energetic particles. This indicates that the TTS system with ladder type magnet array could be useful plasma damage free deposition technique for direct Al cathode sputtering on OLEDs or flexible OLEDs.

• Korean Journal of Materials Research
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• v.2 no.5
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• pp.337-342
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• 1992

Spectroscopic diagnostics on reactive plasmas was carried out in a facing target sputtering unit with BaO +12Fe composite targets and 50% $O_2+$ Ar sputter gas. Spectra of rective plasmas were composed of peaks which were assigned to be Ba, B$a^+$, Fe, FeO, F$e^+$, Ar, $Ar^+$, O, $O^+$. As detecting positions in plasmas were far away from targets, the relative peak intensities of the ions and neutral species were decreased, but the relative intensities of the former decreased faster than those of the latter.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.11
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• pp.1016-1021
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• 2008

The development of the first wall whose major function is to withstand high neutron and heat fluxes is a critical path to fusion power. The materials database and the fabrication technology are being developed for design, construction and safety operation of the fusion reactor. The first wall was designed to consist of the plasma facing armor, the heat sink layer and the supporting plates. and Porous materials are of significant interest due to their wide applications in catalysis, separation, lightweight structural materials. In this study, the characteristics of the sintering process of SiC ceramic, $SiC_f$/SiC composite and porous $C_f$/SiC composite have been introduced order to study of the fusion blanket materials and heat-exchange pannel.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.404-405
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• 2007

Tin-doped indium thin film is outstanding material among transparent Conductive Oxide (TCO) materials. ITO thin films show a low electrical resistance(<$10^{-4}\;[{\Omega}{\cdot}m]$) and high transmittance(>80%) in the visible range. ITO thin films usually have been deposited on the glass substrate. In order to apply flexible display, the substrate should have the ability to bend and be deposited without substrate heat. Also properties of ITO thin film depend on what kind of substrate. In this study, we prepared ITO thin film on the polycarbonate (PC) substrate by using Facing Target Sputtering (FTS) system. Before deposition of ITO thin film, PC substrate took plasma surface treatment. The electrical and surface properties of as-deposited thin films were investigated by Hall Effect measurement, UV/VIS spectrometer and the surface property of substrate is investigated by Contact angle measurement.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.83-84
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• 2006

Processing of W-Cu graded materials from attritor-milled W-CuO mixtures is described. The powder reduction steps are investigated by TG and XRD analyses and by microstructural observations (SEM, TEM). Sintering of reduced powder with different compositions is analysed by dilatometry. Sintering behaviour of the graded component processed by co-compaction of a 10/20/30wt%Cu multi-layer material is briefly discussed. Liquid Cu migration is observed and smooths the composition gradient. Perspectives to control this migration are discussed.