• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.390-393
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• 2001

This study demonstrated the feasibility of tape casting method to fabricate soda borosilicate glass-coated stainless steel electrostatic chucks(ESC) for low temperature semiconductor processes. The glass coatings on the stainless steel substrates ranged from 100 $\mu\textrm{m}$ to 150 $\mu\textrm{m}$ thick. The adhesion of the glass coatings was found to be excellent such that it was able to withstand moderate impact tests and temperature cycling to over 300$^{\circ}C$ without cracking and delamination. The electrostatic clamping pressure generally followed the theoretical voltage-squared curve except at elevated temperatures and higher applied voltages when deviations were observed to occur. The deviation is due to increased leakage current at higher temperature and applied voltage as the electrical resistivity drops.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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• pp.1663-1664
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• 2006

Carbon films was grown on Si substrates using the method of electrolysis for methanol liquid. Deposition parameters for the growth of the carbon films were current density for the electrolysis, methanol liquid temperature and electrode spacing between anode and cathode. We examined electrical resistance and the surface morphology of carbon films formed under various conditions specified by deposition parameters. It was clarified that the high electrical resistance carbon films with smooth surface morphology are grown when a distance between the electrodes was relatively wider. We found that the electrical resistance in the films was independent of both current density and methanol liquid temperature for electrolysis. The temperature dependence of the electrical resistance in the low resistance carbon films was different from one obtained in graphite.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.553-554
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• 2006

Carbon films was grown on Si substrates using the method of electrolysis for methanol liquid. Deposition parameters for the growth of the carbon films were current density for the electrolysis. methanol liquid temperature and electrode spacing between anode and cathode. We examined electrical resistance and the surface morphology of carbon films formed under various conditions specified by deposition parameters. It was clarified that the high electrical resistance carbon films with smooth surface morphology are grown when a distance between the electrodes was relatively wider. We found that the electrical resistance in the films was independent of both current density and methanol liquid temperature for electrolysis. The temperature dependence of the electrical resistance in the low resistance carbon films was different from one obtained in graphite.

• JSTS:Journal of Semiconductor Technology and Science
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• 제17권2호
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• pp.265-270
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• 2017

4H-SiC has attracted attention for high-power and high-temperature metal-oxide-semiconductor field-effect transistors (MOSFETs) for industrial and automotive applications. The gate oxide in the 4H-SiC MOS system is important for switching operations. Above $1000^{\circ}C$, thermal oxidation initiates $SiO_2$ layer formation on SiC; this is one advantage of 4H-SiC compared with other wide band-gap materials. However, if post-deposition annealing is not applied, thermally grown $SiO_2$ on 4H-SiC is limited by high oxide charges due to carbon clusters at the $SiC/SiO_2$ interface and near-interface states in $SiO_2$; this can be resolved via low-temperature deposition. In this study, low-temperature $SiO_2$ deposition on a Si substrate was optimized for $SiO_2/4H-SiC$ MOS capacitor fabrication; oxide formation proceeded without the need for post-deposition annealing. The $SiO_2/4H-SiC$ MOS capacitor samples demonstrated stable capacitance-voltage (C-V) characteristics, low voltage hysteresis, and a high breakdown field. Optimization of the treatment process is expected to further decrease the effective oxide charge density.

• 한국재료학회지
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• 제16권2호
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• pp.99-105
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• 2006

This paper reports an improved bonding method using the IPA (isopropyl alcohol) assisted low-temperature bonding process for the PMMA (polymethylmethacrylate) micro CE (capillary electrophoresis) chip. There is a problem about channel deformations during the conventional processes such as thermal bonding and solvent bonding methods. The bonding test using an IPA showed good results without channel deformations over 4 inch PMMA wafer at $60^{\circ}C$ and 1.3 bar for 10 minutes. The mechanism of IPA bonding was attributed to the formation of a small amount of vaporized acetone made from the oxidized IPA which allows to solvent bonding. To verify the usefulness of the IPA assisted low-temperature bonding process, the PMMA micro CE chip which had a $45{\mu}m$ channel height was fabricated by hot embossing process. A functional test of the fabricated CE chip was demonstrated by the separation of fluorescein and dichlorofluorescein. Any leakage of liquids was not observed during the test and the electropherogram result was successfully achieved. An IPA assisted low-temperature bonding process could be an easy and effective way to fabricate the PMMA micro CE chip and would help to increase the yield.

• 한국재료학회지
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• 제14권11호
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• pp.795-801
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• 2004

The injection molded Fe sintered bodies were fabricated using two kinds of Fe powders haying 50 nm and $3\sim5{\mu}m$ in diameter. In the using of Fe powder having 50 nm in diameter, the comparatively dense bodies ($94\sim97\%$) were obtained even at low sintering temperature ($600\sim700^{\circ}C$), while in the sintered bodies ($1000^{\circ}C$) using $3\sim5{\mu}m$ Fe powder, their relative densities showed low values about $93\%$, although they were strongly depend on the sintering temperature and volume ratio of Fe powder and binder. In the sintered bodies using of 50 nm Fe powders, the volume shrinkage and grain size increased as the sintering temperature increased, but the values of hardness decreased. In the sample sintered at $650^{\circ}C$, the values of relative density, volume shrinkage and grain size were $96\%,\;37\%\;and\;0.97{\mu}n$, respectively and the minimum value of wear depth was obtained due to combination of fine grain and comparatively high density.

• 한국전기전자재료학회논문지
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• 제21권8호
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• pp.687-694
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• 2008

This paper is focused on the improvement of MOS device reliability related to deuterium process. The injection of deuterium into the gate oxide film was achieved through two kind of method, high-pressure annealing and low-energy implantation at the back-end of line, for the purpose of the passivation of dangling bonds at $SiO_2/Si$ interface. Experimental results are presented for the degradation of 3-nm-thick gate oxide ($SiO_2$) under both negative-bias temperature instability (NBTI) and hot-carrier injection (HCI) stresses using P and NMOSFETs. Annealing process was rather difficult to control the concentration of deuterium. Because when the concentration of deuterium is redundant in gate oxide excess traps are generated and degrades the performance, we found annealing process did not show the improved characteristics in device reliability, compared to conventional process. However, deuterium ion implantation at the back-end process was effective method for the fabrication of the deuterated gate oxide. Device parameter variations under the electrical stresses depend on the deuterium concentration and are improved by low-energy deuterium implantation, compared to conventional process. Our result suggests the novel method to incorporate deuterium in the MOS structure for the reliability.

• 한국세라믹학회지
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• 제55권4호
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• pp.358-363
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• 2018

To improve the polarization property of cathodes, which is the main factor limiting the performance of protonic ceramic fuel cells (PCFCs), $K_2NiF_4-type$ $Pr_2NiO_{4+{\delta}}$, which is expected to exhibit a triple conducting property (proton, oxygen ion, and hole conductions) was applied to PCFCs and its properties were investigated. Low-temperature microwave heat-treatment was used to achieve both sufficient interface adhesion between the electrolyte and the cathode layers and suppression of the secondary phase formation due to migration of elements such as barium and cerium. Through this fabrication method, a high performance of $0.82W{\cdot}cm^{-2}$ and low ohmic resistance of $0.06{\Omega}{\cdot}cm^2$ were obtained in an $Ni-BaCe_{0.55}Zr_{0.3}Y_{0.15}O_{3-{\delta}}$ | $BaCe_{0.55}Zr_{0.3}Y_{0.15}O_{3-{\delta}}$ | $Pr_2NiO_{4+{\delta}}$ single cell at $650^{\circ}C$. This result verifies that the $K_2NiF_{4+{\delta}}-type$ cathode shows good chemical compatibility which, in turn, will make it a potent candidate as a PCFC cathode.

• Macromolecular Research
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• 제11권2호
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• pp.122-127
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• 2003

A glass-like carbon was fabricated using furan resin. The influence of heat treatment temperature during fabrication process on the chemical and micro-structural changes was studied by various analytical and spectroscopic methods including TGA, FT-IR, CHN, TEM and XRD. The chemical resistance properties of the fabricated glass-like carbon were also investigated. It has been found that the heat-treated samples at higher temperature up to 2600 $^{\circ}C$ in $N_2$ atmosphere had little weight loss, small amounts of functional groups, and high carbon content. The fabricated glass-like carbons upon heat treatment at 2600 $^{\circ}C$ showed an amorphous stage without any grain growth and/or reconstruction of structure. The glass-like carbon had much better chemical resistance than the artificial graphite, and exhibited a high chemical resistance due to its low surface areas, minimum impurities, and low graphite crystallites.

• 한국세라믹학회지
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• 제54권5호
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• pp.395-399
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• 2017

The thermal properties and crystallization behavior of calcium phosphate glass fabricated using eggshell were examined. Nature eggshell has several impurities in the main component of $CaCO_3$. To manufacture calcium phosphate glass, washed eggshell was dissolved in aqua-regia while adding a solution of isopropyl alcohol, D. I. water and phosphoric acid. The calcined precursor was melted at $1000^{\circ}C$, and the glass ($T_g$ : $540^{\circ}C$) was crystallized at $620{\sim}640^{\circ}C$, which temperature range is relatively low compared to the crystallization temperature of other general types of calcium phosphate glass. The calcium phosphate glass using eggshell was successfully crystallized without any additional nucleating agents due to the multiple effects of impurities such as $Fe_2O_3$, $Al_2O_3$, SrO and $SiO_2$ in the eggshell. The main crystalline phase was ${\beta}-Ca(PO_3)_2$ and a biocompatible material, hydroxyapatite, was also observed. The crystallization process was completed under the condition of a holding time of only 1 h at the low temperature.