• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2003.10a
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• pp.118-118
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• 2003

In a rolling wire probe, a key component of an inspection apparatus for PDP electrode patterns, the electric performance of it is known to be strongly dependent on the surface condition of a collet pin, a needle pin, and a wire. However, the collet and needle pins rotate very rapidly in contact with each other, which results in the degradation of the surface by the heat and friction and finally the formation of black wear marks on the surface after a several hundred hours test. Once the black wear marks appear on the surface, the electric resistance of the probe increases sharply and so the integrity of the probe is severely damaged. In this experiment, TiN coating, which has excellent electric conductances and good wear-resistance, has been applied on the surface of collect and needle pins for preventing the surface damages. In order to achieve the homogeneous coating with a good adhesion property, special coating substrate stages and jigs were designed and applied during coating. TiN has been deposited using 99.999% Titanium target by a DC reactive sputtering method. According to the components and jigs, processing parameters, such as DC power, RF bias and the flow rate ratio of Ar and N$_2$ used as reactive gases, has been controlled to obtain good TiN films. Detailed problems and solutions for applying the new substrate stages and jigs will be discussed.

• Journal of Sensor Science and Technology
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• v.22 no.4
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• pp.239-243
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• 2013

Several methods are available to measure the oxidation of edible oils, such as their acid, peroxide, and anisidine values. However, these methods require large quantities of reagents and are time-consuming tasks. Therefore, a more convenient and time-saving way to measure the oxidation of edible oils is required. In this study, an edible oil-condition sensor was fabricated using single-walled nanotubes (SWNTs) made using the spray deposition method. SWNTs were dispersed in a dimethylformamide solution. The suspension was then sprayed using a spray gun onto a prefabricated Au/Ti electrode. To test the sensor, oxidized edible oils, each with a different acid value, were prepared. The SWNT sensors were immersed into these oxidized oils, and the resistance changes in the sensors were measured. We found that the conductivity of the sensors decreased as the oxidation level of the oil increased. In the case of the virgin oil, the resistance change ratio in the SWNT sensor S(%) = {[(Rf - Ri)]/Ri}(%) was more than 40% after immersion for 1 min. However, in the case of the oxidized oil, the resistance change ratio decreased to less than that of the response of the virgin oil. This result suggests that the change in the oil components induced by the oxidation process in edible oils is related to the conductivity change in the SWNT sensor.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.331-332
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• 2007

Surface micromachined SiC devices have readily been fabricated from the polycrystalline (poly) 3C-SiC thin film which has an advantage of being deposited onto $SiO_2$ or $Si_3N_4$ as a sacrificial layer. Therefore, in this work, magnetron reactive ion etching process which can stably etch poly 3C-SiC thin films grown on $SiO_2$/Si substrate at a lower energy (70 W) with $CHF_3$ based gas mixtures has been studied. We have investigated the etching properties of the poly 3C-SiC thin film using PR/Al mask, according to $O_2$ flow rate, pressure, RF power, and electrode gap. The etched RMS (root mean square), etch rate, and etch profile of the poly 3C-SiC thin films were analyzed by SEM, AFM, and $\alpha$-step.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.472-473
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• 2007

The $(Sr_{1-x}Ca_x)TiO_3$(ST) thin films are deposited on Pt-coated electrode(Pt/TiN/$SiO_2$/Si) using RF sputtering method with substitutional contents of Ca. The maximum grain of thin films is obtained by substitution of Ca at 15[mol%]. Also, the composition of ST thin films were closed to stoichiometry(1.081~1.117 in A/B ratio). The dielectric constant changes almost linearly in temperature ranges of -80~+90[$^{\circ}C$]. The current-voltage characteristics of ST15 thin films showed the increasing leakage current as the measuring temperature increases.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.33-36
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• 1999

In this paper, $Ba_{0.5}$Sr$_{0.5}$TiO$_3$ thin-films were prepared on Pt/Ti/Si0$_2$/Si substrates by RF magnetron sp-uttering method. We investigated electric and dielectric properties of BST thin-films with various ann-ealing temperature using in-sute RTA. Deposition conditions of BST films were set substrate temperat-ure, 30$0^{\circ}C$ and working gas ratio, Ar:O$_2$=90:10. After BST films deposited, we fabricated a capacitor of MIM structure with Al top electrode for measurement. Post-annealing using RTA performed at 40$0^{\circ}C$, $600^{\circ}C$, 80$0^{\circ}C$ for 60 sec, respectively. Also we exacted crystallization and composition of BST thin-films by XRD analysis. In measurement result, this capacitors showed a dielectric constant of about 200 at 1MHz and leakage current density of 5$\times$10$^{-8}$ A/$\textrm{cm}^2$ at 1.5V Microstructure of BST thin-films exhibited effective quality in low-temperature annealed 71ms than high-temperature annealed 71ms.s.s.

• Journal of Power System Engineering
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• v.15 no.5
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• pp.49-53
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• 2011

This study concerns about wireless power generation that uses the energy harvester with EAP actuator. The UWSN(Underwater Wireless Sensor Network) has been considered many times by many researches. Because the information of underwater is getting important to secure the resource or to predict the meteorological phenomena. But the sensor node in the UWSN is driven by the acoustic wave to communicate with other sensor node. And this acoustic wave usually spends a 100 times energy than the RF(Radio Frequency) wave due to transfermation medium(sea water). Therefore the power source of the sensor node is very important that is needed to improve in the UWSN. For this purpose, the energy harvester is made by the acrylic elastomer in this study. And the electrode is modified with an aluminum impurity to improve the efficiency of energy harvester. After that, the modified energy harvester is experimented to confirm the improvement of the energy efficiency.

• Journal of the Semiconductor & Display Technology
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• v.8 no.2
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• pp.11-14
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• 2009

The $Sr_{0.7}Bi_{2.3}Nb_2O_9$(SBN) thin films are deposited on Pt-coated electrode(Pt/Ti/$SiO_2$/Si) using RF sputtering method at various $Ar/O_2$ ratio. We investigated the effect of deposition condition(specially $Ar/O_2$ ratio) on the structural properties of SBN thin film. As $Ar/O_2$ ratio was increased, the peaks in the XRD pattern became more sharp. Also, the peaks(008)(115)(220) in 80/20 of $Ar/O_2$ ratio were suddenly appeared. The optimum of the rougness showed about 4.33 nm in 70/30 of $Ar/O_2$ ratio. The crystallinity of SBN thin films were increased with the increase of $Ar/O_2$ ratio. Also, Deposition rate of SBN thin films was about 4.17 nm/min in 70/30 of $Ar/O_2$ ratio. The capacitance of SBN thin films were increased with the increase of $Ar/O_2$ ratio.

• Journal of the Korean institute of surface engineering
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• v.52 no.3
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• pp.145-149
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• 2019

Transparent and conductive ZnO/Ag/SnO2 (ZAS) tri-layer films were deposited onto glass substrates at room temperature by using radio frequency (RF) and direct current (DC) magnetron sputtering. The thickness values of the ZnO and $SnO_2$ thin films were kept constant at 50 nm and the value for Ag interlayer was varied as 5, 10, 15, and 20 nm. In the XRD pattern the diffraction peaks were identified as the (002) and (103) planes of ZnO, while the (111), (200), (220), and (311) planes could be attributed to the Ag interlayer. The optical transmittance and electrical resistivity were dependent on the thickness of the Ag interlayer. The ZAS films with a 10 nm thick Ag interlayer exhibited a higher figure of merit than the other ZAS films prepared in this study. From the observed results, a ZAS film with a 10 nm thick Ag interlayer was believed to be an alternative transparent electrode candidate for various opto-electrical devices.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.34 no.1
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• pp.39-43
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• 2021

In the case of ZnO:Al thin films, it is the best material that can replace ITO that is mainly used as a transparent electrode in electronic devices such as solar cells and flat-panel displays. In this study, ZnO:Al films were fabricated by using the RF dual magnetron sputtering method at various substrate temperatures. As the substrate temperature increased, the crystallinity of the ZnO:Al thin films was improved, and the electrical conductivity and electrical properties of the thin film improved owing to the increase in grain size. In addition, the surface roughness of the ZnO:Al thin films increased due to changes in the surface and density of the thin films. Moreover, the substrate temperature increased the density of thin films and improved their transmittance. To be applied to solar cells and other several electronic devices in the future, the hardness and adhesion properties of the thin film improve as the substrate temperature increases.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2003.05a
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• pp.53-53
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• 2003

Plasma polymerized organic thin films were deposited on Si(100) glass and metal substrates using thiophene and ethylcyclohexane precursors by PECVD method. In order to compare electrochemical properties of the as-grown thin films, the effects of the RF plasma power in the range of 30~100 W. AFM showed that the polymer films with smooth surface and sharp interface could be grown under various deposition conditions. Impedance analyzer was utilized for the determination of I-V curve for leakage current density and C-V for dielectric constants, respectively. To obtain C-V curve, we used a MIM structure of metal(Al)-insulator(plasma polymerized thin film)-metal(Pt) structure. Al as the electrode was evaporated on the thiophene films that grew on Pt coated silicon substrates, and the dielectric constants of the as-grown films were then calculated from C- V data measured at 1MHz. From the electrical property measurements such as I-V and C-V characteristics, the minimum dielectric constant and the best leakage current of thiophene thin films were obtained to be about 3.22 and $1{\;}{\times}10^{-11}{\;}A/cm^2$. However, in case of ethylcyclohexane thin films, the minimum dielectric constant and the best leakage current were obtained to be about 3.11 and $5{\;}{\times}10^{-12}{\;}A/cm^2$.