• 대한방사선기술학회지:방사선기술과학
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• 제33권3호
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• pp.179-184
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• 2010

나노 공간분해능을 갖는 영상을 얻기 위한 경엑스선 현미경 시스템에서는 단색 엑스선이 요구된다. 엑스선관에서 발생되는 화이트 빔으로부터 8.4 keV의 텅스텐 $L_{\alpha}$ 특성방사선을 84% 이상 반사시킬 수 있는 5.65 nm의 단위막 두께를 가지는 C/W 다층박막 거울을 설계하였고, 이온빔 스파터링 장치를 이용하여 $50{\times}50\;mm$ 크기로 제작하였다. 제작된 C/W 다층박막 거울은 99.5% 이상의 균일도(Uniformity)를 가지며, TEM 사진을 이용해 그 구조를 확인하였다. 8.05 keV의 구리 특성방사선을 광원으로 하는 엑스선 반사율 측정 장치를 이용한 다층박막 거울의 반사율을 측정함으로써 C/W 다층박막 거울의 8.4 keV에서의 반사율을 예상할 수 있었다. 제작된 C/W 다층박막 거울과 엑스선관을 이용하여 8.4 keV의 특성방사선을 획득함으로써 단색 엑스선을 획득하였다. 이때의 반사율은 77.1%였고, 단색 엑스선의 반치폭은 0.21 keV이었다. 엑스선관에서 높은 효율로 단색 엑스선을 획득할 수 있어 실험실 규모의 경엑스선 현미경 장치의 광원으로써 사용될 수 있는 가능성을 확인하였고, 다층박막 거울의 단위막 두께를 수 나노미터로 제작한다면 17.5 keV의 몰리브덴 특성방사선에 해당하는 단색 엑스선을 얻어 유방촬영에도 적용할 수 있을 것이다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.19-19
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• 2009

TiNxOy/TiNx multilayer thin films with a high resistance (~ k$Omega$) were deposited on SiO2/Si substrates at room temperature by sputtering. The TiNx thin films show island and smooth surface morphology in samples prepared by dc and rf magnetron sputtering, respectively. TiNxOy/TiNx multilayer has been developed to control temperature coefficient of resistance (TCR) by the incorporation of TiNx layer (positive TCR) inserted into TiNxOy layers(negative TCR). Electrical and structural properties of sputtered TiNxOy/TiNx multilayer films were investigated as a function of annealing temperature. In order to achieve a stable high resistivity, multilayer films were annealed at various temperatures in oxygen ambient. Samples annealed at 700 oC for 1 min exhibit a good TCR value and a stable high resistivity.

• Korea-Australia Rheology Journal
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• 제15권1호
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• pp.1-7
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• 2003

A new method is introduced to build up organic/organic multilayer films composed of cationic poly(allylamine hydrochloride) (PAH) and negatively charged poly (sodium 4-styrenesulfonate) (PSS) using the spinning process. The adsorption process is governed by both the viscous force induced by fast solvent elimination and the electrostatic interaction between oppositely charged species. On the other hand, the centrifugal and air shear forces applied by the spinning process significantly enhances desorption of weakly bound polyelectrolyte chains and also induce the planarization of the adsorbed polyelectrolyte layer. The film thickness per bilayer adsorbed by the conventional dipping process and the spinning process was found to be about 4 ${\AA}$ and 24 ${\AA}$, respectively. The surface of the multilayer films prepared with the spinning process is quite homogeneous and smooth. Also, a new approach to create multilayer ultrathin films with well-defined micropatterns in a short process time is Introduced. To achieve such micropatterns with high line resolution in organic multilayer films, microfluidic channels were combined with the convective self-assembly process employing both hydrogen bonding and electrostatic intermolecular interactions. The channels were initially filled with polymer solution by capillary pressure and the residual solution was then removed by the .spinning process.

• 대한전자공학회논문지
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• 제25권4호
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• pp.422-429
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• 1988

The photoconductive multilayer of Se-As(hole blocking layer)/Se-As-Te (photoconductive layer) /Se-As (layer for supporiting hole transport)/Se-As(layer or controlling total capacitance)/Sb2S3(electron blocking layer) was fabricated and its electrical and optical properties were investigated. The photoconductive multilayer is made of evaporated a-Se as the base material, doped with As and Te to prevent the crystallization of a-Se and to enhance red sensitivity, respectively. The multilayer with good image reproducibility has the following deposition condition. The first layer has the thickness of 250\ulcornerat the deposition rate of 250\ulcornersec. The second layer has the thickness of 800\ulcornerat the deposition rate of 250\ulcornersec. The third layer has the thickness of 125\ulcornerat the deposition rate of 250\ulcornersec. The fourth layer has the thickness of 1700\ulcornerunder the Ar gas ambient of 50x10**-3torr. The image pick-up tube, employing this multilayer demonstrates the following characteristics. The photosensitivity is 0.8, the resolution limit is above 300TV line, and the decay lag is about 7%. And spectral response convers the whole visible range. Therfore the application to color TV camera is expected.

• 마이크로전자및패키징학회지
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• 제8권2호
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• pp.19-24
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• 2001

EUV 노광공정의 반사형 노광계 및 마스크에 사용되는 Mo/Si 다층박막 착탁 시 발생하는 각 층의 두께 변화와 상호확산 층 (inter-diffusion layer)이 생성될 경우에 대하여 이들이 다층박막 반사도에 미치는 영향을 전산모사를 통하여 알아보았다. 본 연구그룹에서 개발한 다층박막 반사 시뮬레이션 프로그램을 사용하여 Mo/Si 40-period박막의 반사토플 계산한 결과, 각각의 period가 두께의 편챠(28%)를 갖는 경우, 모든 period가 같은 두께를 갖는 다층박막에 비해 최대반사도가 10.8% 감소가 되었으며 두 층간 물질 사이의 상호확산(interdiffustion) 층을 가정하였을 경우, 다층박막의 경우 그렇지 않은 경우에 비해 4.7%의 최대반사도가 감소가 예상되었다. 그리고 각 층의 적층에 따른 반사도의 변화를 시뮬레이션 프로그램을 통해 계산한 결과 반사도는 25층까지 계속 증가하며 26층부터 불규칙한 경향성을 가지며 증가와 감소를 반복함을 알 수 있었다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.420-423
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• 2008

The characteristics of $Al_2O_3/Ag/Al_2O_3$ multilayer passivaton prepared by twin target sputtering (TTS) system for organic light emitting diodes. The $Al_2O_3/Ag/Al_2O_3$ multilayer thin film passivation on a PET substrate had a high transmittance of 86.44 % and low water vapor transmission rate (WVTR) of $0.011\;g/m^2$-day due to the surface plasmon resonance (SPR) effect of Ag interlayer and effective multilayer structure for preventing the intrusion of water vapor. Using synchrotron x-ray scattering and field emission scanning electron microscope (FESEM) examinations, we investigated the growth behavior of Ag layer on the $Al_2O_3$ layer to explain the SPR effect of the Ag layer. This indicates that an $Al_2O_3/Ag/Al_2O_3$ multilayer passivation is a promising thin film passivation scheme for organic based flexible optoelectronics.

• Journal of Electrochemical Science and Technology
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• 제2권4호
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• pp.193-197
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• 2011

The influences of the thickness and microstructure of Fe layer on the electrochemical performances of Fe/Si multilayer thin film anodes were investigated. The Fe/Si multilayer films were prepared by electron beam evaporation, in which Fe layer was deposited with/without simultaneous bombardment of Ar ion. The kinetics of Li insertion/extraction reactions in the early stage are slowed down with increasing the thickness of Fe layer, but such a slowdown seems to be negligible for thin Fe layers less than about $500{\AA}$. When the Fe layer was deposited with ion bombardment, even the $300{\AA}$ thick Fe layer significantly suppress Li diffusion through the Fe layer. This is attributed to the dense microstructure of Fe layer, induced by ion beam assisted deposition (IBAD). It appears that the Fe/Si multilayer films prepared with IBAD show good cyclability compared to the film deposited without IBAD.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.1575-1577
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• 2009

We have investigated the characteristics of transparent indium zinc oxide(IZO)/Ag/IZO multilayer electrode grown on polyethylene terephthalate (PET) substrates using a specially designed roll-to-roll sputtering system for use in flexible device are described. By the continuous R2R sputtering of the bottom IZO, Ag, and top IZO layers at room temperature, we were able to fabricate an IZO-Ag-IZO multilayer electrode with a sheet resistance of 6.15 ${\Omega}$/square, optical transmittance of 87.4 %, and figure of merit value of 42.03 10-3 ${\Omega}$-1. In addition, the IZO-Ag-IZO multilayer electrode exhibited superior flexibility to the RTR sputter grown single ITO electrode, due to the existence a ductile Ag layer between the IZO layers. This indicates that the RTR sputtered IZO-Ag-IZO multilayer is a promising flexible electrode that can substitute for the conventional single ITO electrode grown by bath type sputtering for use in low cost flexible device, due to its low resistance, high transparency, superior flexibility and fast preparation by the R2R process.

• 한국전기전자재료학회논문지
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• 제20권12호
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• pp.1044-1048
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• 2007

With development of electronic products the demands for miniaturization and weight-lightening have increased until a recent date. Accordingly, The effort to substitute glass substrates was widely made. However, polymer substrates have weak point that substrates were damaged at high temperature. In this paper, we deposited transparent conductive film at low temperature. And we inserted Au thin film between oxide to compensate for deteriorated electrical characteristics. Ga-doped ZnO(GZO) multilayer coatings were deposited on glass substrate by DC sputtering. The optimization of deposition conditions of both AZO and Au layers were performed to obtain better electrical and optical characteristics in advance. We presumed that the properties of multilayer were affected by the deposition process of both GZO and Au layers. The best multilayer coating exhibited the resistivity of $2.72{\times}10^{-3}\;{\Omega}-cm$ and transmittance of 77 %. From these results, we can confirm a possibility of the application as transparent conductive electrodes.

• Journal of Magnetics
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• 제8권3호
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• pp.108-112
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• 2003

We report the experimental finding that there exists a transition of magnetization reversal process with varying the applied field in Co/Pd multilayer. We have measured the wall-motion speed V and the nucleation rate R during magnetization reversal via time-resolved direct domain observation, where the magnetization reversal process of Co/Pd multilayer is found to take a transition from thermal activation process to viscous process at the critical field of about 1.87 H$\_$C/ (coercivity). In the thermal activation regime, we find that the field dependences of two activation volumes for the wall-motion process and the nucleation process are different with each other, which reveals that the wall-motion and nucleation experience completely different interactions. In the viscous regime, we find that the wall-mobility is much smaller than a typical value for the sandwiched Co films, which implies that the Co/Pd interfaces in multilayer substantially contribute to the dynamic dissipation.