• Journal of Sensor Science and Technology
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• v.26 no.4
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• pp.228-234
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• 2017

Gas sensors based on metal-oxide-semiconductors are predominantly used in numerous applications including monitoring indoor air quality and detecting harmful substances such as volatile organic compounds. Nanostructures, e.g., nanoparticles, nanotubes, nanodomes, or nanofibers, have been widely utilized to improve the gas sensing properties of metal-oxide-semiconductors by increasing the effective surface area participating in the surface reaction with target gas molecules. Recently, 1-dimensional (1D) metal oxide nanostructures fabricated using glancing angle deposition (GAD) method with e-beam evaporation have been widely employed to increase the surface-to-volume ratio significantly with large-area uniformity and reproducibility, leading to promising gas sensing properties. Herein, we provide a brief overview of 1D metal oxide nanostructures fabricated using GAD and their gas sensing properties in terms of fabrication methods, morphologies, and additives. Moreover, the gas sensing mechanisms and perspectives are presented.

• Journal of the Semiconductor & Display Technology
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• v.13 no.2
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• pp.1-5
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• 2014

Transparent and conducting aluminum-doped ZnO electrodes were fabricated by atomic layer deposition methods. The electrode showed the lowest resistivity of $5.73{\times}10^{-4}{\Omega}cm$ at a 2.5% cyclic layer deposition ratio of Trimethyl-aluminum and Diethyl-zinc chemicals. The electrodes showed minimum resistivity when deposited at a temperature of $225^{\circ}C$. The electrode also showed optical transmittance of about 92% at 300 nm. An organic solar cell made with a 300-nm-thick aluminum-doped ZnO electrode exhibited 2.0% power conversion efficiency.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.9
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• pp.741-746
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• 2009

Compare to conventional Indium Tin Oxide (ITO) film deposition methods, cesium assisted sputtering method has been shown superior electrical, mechanical, and optical film properties. However, it is not easy to use cesium assisted sputtering method since ITO film properties are very sensitive to Cesium assisted equipment condition but their mechanism is not yet clearly defined physically or mathematically. Therefore, to optimize deposited ITO film characteristics, development of accurate and reliable process model is essential. For this, in this work, we developed ITO film deposition process model using neural networks and design of experiment (DOE). Developed model prediction results are compared with conventional statistical regression model and developed neural process model has been shown superior prediction results on modeling of ITO film thickness, sheet resistance, and transmittance characteristics.

• Journal of the Semiconductor & Display Technology
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• v.10 no.2
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• pp.83-89
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• 2011

In this study, we investigated the effects of shutter control by Reactive Magnetron Sputtering using Inductively-Coupled Plasma(ICP) for obtaining ZnO thin films with high purity. The surface morphologies and structure of deposited ZnO thin films were characterized using Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and X-ray Diffractometer (XRD). Also, optical and chemical properties of ZnO thin films were analyzed by Spectroscopic Ellipsometer (SE) and X-ray Photoelectron spectroscopy (XPS). As a result, it observed that ZnO thin films grown at reactive sputtering using shutter control and ICP were higher density, lower surface roughness, better crystallinity than other conventional sputtering deposition methods. For obtaining better quality deposition ZnO thin films, we will investigate the effects of substrate temperature and RF power on shutter control by a reactive magnetron sputtering using inductively-coupled plasma.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.5
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• pp.468-473
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• 2008

A MgO layer is used as electrode protective film in the alternating current plasma display panel (AC PDP). The properties of MgO layer are thought to be one of the most important factors that affects the panel reliability through the firing voltage variation. In this study, we investigated the relations between the surface characteristics and e-beam evaporation process parameters such as deposition rate, temperature of substrate and distance between the MgO pellet and substrate. To produce the MgO layer of (200) crystal orientation, we suggest the high temperature of the substrate, the long distance between the pellet and substrate and the high deposition rate.

• Electrical & Electronic Materials
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• v.9 no.7
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• pp.727-732
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• 1996

In the present paper, the Cu films 4.mu.m thick were deposited by RF magnetron sputtering method on Si wafer. The Cu films deposited at a condition of 100W, 10mtorr exhibited a low electrical resistivity of 2.3.mu..ohm..cm and densed microstructure, poor adhesion. The Cu films grown by 200W, 20mtorr showed a good adhesion property and higher electrical resistivity of 7.mu..ohm..cm because of porous columnar microstructure. Therefore, The Cu films were deposited by double layer deposition method using RF magnetron sputtering on Si wafer. The dependence of the electrical resistivity, adhesion, and reflectance in the CU films [C $U_{4-d}$(low resistivity) / C $U_{d}$(high adhesion) / Si-wafer] on the thickness of d has been investigated. The films formed with this deposition methods had the low electrical resistivity of about 2.6.mu..ohm..cm and high adhesion of about 700g/cm.m.m.

• Journal of the Korean institute of surface engineering
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• v.22 no.3
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• pp.128-134
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• 1989

Mechanism of cobalt deposition was investigated using the potentiodynamic potentiostatic methods in solution of pH 4 and pH6.4 In all experimental conditions, polarization curves showed two regions with different Tafel slopes and the reaction order of cobalt ion was varied with the pH. It is belived that the deposition mechanism depends not only on the portential but also on the ph.

• Journal of Ceramic Processing Research
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• v.20 no.5
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• pp.464-469
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• 2019

In this study, the electrical conductivity of multi-walled carbon nanotubes (MWCNTs) and polyethylene synthesized by an extrusion process was evaluated. The MWCNTs used exhibited differences in their dispersion characteristics depending on the type of catalyst or synthesis gas used. Thus, the choice of catalyst or synthesis gas significantly affect the physicochemical state of the final MWCNTs and MWCNT-based composites. In this investigation, the characteristics of MWCNTs were analyzed in four cases by introducing ethylene and propylene gas to each catalyst synthesized using deposition precipitation and spray drying methods. The MWCNT-based composites synthesized using the catalyst prepared by deposition precipitation and the ethylene synthesis gas showed the best electrical conductivity. In principle, the morphologies of the MWCNTs indicate that the smaller the aggregate size and bundle thickness, the better the electrical conductivity of the MWCNT composites. This implies that the network is well-formed.

• Progress in Superconductivity and Cryogenics
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• v.9 no.4
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• pp.1-6
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• 2007

We describe methods for depositing high temperature superconducting films on textured metal tapes by reactive co-evaporation (RCE). We discuss how RCE can be used to deposit on moving tape in a continuous fashion in a Garching-style process. Results are presented on films deposited by RCE at Los Alamos on IBAD-MgO textured tapes. The performance achieved, attaining over 500A/cm-width in self-field at 75.5 K, is competitive with the best results obtained by other processes for coated conductors. Tape production throughput is critical for the economics of the process and high deposition rates achieved in RCE are attractive for this. We present a detailed cost analysis model for HTS deposition using an RCE Garching process. The results indicate that HTS deposition can cost $<$5/kA{\cdot}m$ in a scaled up manufacturing environment.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.2
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• pp.109-124
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• 2023

For decades, sputtering as a physical vapor deposition (PVD) method has been a widely used technique for film coating processes. The sputtering enables oxides, metals, alloys, nitrides, etc to be deposited on a wide variety of substrates from silicon wafers to polymer substrates. Meanwhile, transparent conductive oxides (TCOs) have played important roles as electrodes in electrical applications such as displays, sensors, solar cells, and thin-film transistors. TCO films fabricated through a sputtering process have a higher quality leading to an improved device performance than other films prepared with other methods. In this review, we discuss the mechanism of sputtering deposition and detail the TCO materials. Related technologies (processing conditions, materials, and applications) are introduced for electrical applications.