• Current Photovoltaic Research
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• v.2 no.3
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• pp.110-114
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• 2014

We propose a low temperature sol-gel ZnO/Ag nanowire composite thin film to fulfill low temperature and low cost requirements, which are essential criteria in future flexible electronic devices. In this proposed thin film, Ag nanowire plays the role of electrical conduction, and sol-gel ZnO provides a structural medium with a high visible transmittance. Low temperature restriction in the sol-gel fabrication process prevents sufficient oxidation of Zn acetate precursors, which were solved by a post-coating treatment with ultraviolet light irradiation. Composite thin film formation was performed by spin coating methods with a mixed precursor solution or in a sequential manner. We obtained an average visible transmittance larger than 85% and a sheet resistance smaller than $50{\Omega}/sq$. After optimization in a fabricated composite transparent conductive thin film with the thickness around 100 nm. Similar experimental demonstration in a flexible substrate (polyethyleneterephthalate) was successful, which implies a promising application opportunity of this technology.

• Journal of the Korean Ceramic Society
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• v.37 no.7
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• pp.665-672
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• 2000

The ferroelectric YMnO3 thin films were prepared by MOD(metal-organic decomposition) method with Y- and Mn-acetylacetonate as starting materials. Thin films were grown on various substrates by spin-coating technique. The crystalline phases of the thin films were identified by X-ray diffractometer as a function of heat-treatment temperature, pH of coating solution and substrate. In addition, the effect of Mn/Y molar ratio(0.8~1.2) on the formation of hexagonal-YMnO3 phase was investigated. In forming highly c-axisoriented hexagonal-YMnO3 single phase, the Pt coated Si substrate was more effective than the bare Si substrate, and the optimum heat-treatment condition was at 82$0^{\circ}C$ for 30 min. Higher Mn/Y molar ratio within 0.8~1.2 and pH of YMnO3 precursor solution within 0.5~2.5 favored formation of ferroelectric hexagonal phase rather than orthorhombic phase. Leakage current density of the hexagonal-YMnO3 thin film formed on Pt(111)/TiO2/SiO2/Si substrate was low enough as 0.4~4.0$\times$10-8(A/$\textrm{cm}^2$) at 5 V and its remanent polarization(Pr), calculated from the P-E hysteresis loop, was 3 nC/$\textrm{cm}^2$.

• Journal of Sensor Science and Technology
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• v.15 no.2
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• pp.148-152
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• 2006

This paper describes the fabrication of SiCN microstructures for super-high temperature MEMS using photopolymerization of pre-ceramic polymer. In this work, polysilazane liquide as a precursor was deposited on Si wafers by spin coating, microstructured and solidificated by UV lithography, and removed from the substrate. The resulting solid polymer microstructures were cross-linked under HIP process and pyrolyzed to form a ceramic of withstanding over $1400^{\circ}C$. Finally, the fabricated SiCN microstructures were annealed at $1400^{\circ}C$ in a nitrogen atmosphere. Mechanical characteristics of the SiCN microstructure with different fabrication process conditions were evaluated. The elastic modules, hardness and tensile strength of the SiC microstructure implemented under optimum process condtions are 94.5 GPa, 10.5 GPa and 11.7 N/min, respectively. Consequently, the SiCN microstructure proposed in this work is very suitable for super-high temperature MEMS application due to very simple fabrication process and the potential possiblity of sophisticated mulitlayer or 3D microstructures as well as its good mechanical properties.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.14 no.5
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• pp.187-192
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• 2004

We try to use isopropanol which has low boiling point to prepare ZnO thin films at low temperature. ZnO thin films were prepared by sol-gel spin-coating method using zinc acetate dehydrate-isopropanol-monoethanolamine (MEA) solution. The c-axis preferred orientation and optical properties of ZnO films with preheating temperature have been investigated. ZnO thin films were preheated at 200 to $300^{\circ}C$ with an interval of $25^{\circ}C$ and post-heated at $650^{\circ}C$. The ZnO film preheated at $275^{\circ}C$ and post-heated at $650^{\circ}C$ was highly oriented along c-axis (002) plane, and the surface with homogeneous and dense microstructures was formed having nano-sized grains. The optical transmittance was above 90 % in the visible range and exhibited absorption edges at 368 nm wavelength.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.392-393
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• 2006

This paper describes the fabrication of SiCN microstructures for super-high temperature MEMS using photopolymerization of pre-ceramic polymer. In this work. polysilazane liquide as a precursor was deposited on Si wafers by spin coating. microstructured and solidificated by UV lithography. and removed from the substrate. The resulting solid polymer microstructures were cross-linked under HIP process and pyrolyzed to form a ceramic of withstanding over $1400^{\circ}C$. Finally, the fabricated SiCN microstructures were annealed at $1400^{\circ}C$ in a nitrogen atmosphere. Mechanical characteristics of the SiCN microstructure with different fabrication process conditions were evaluated. The elastic modules. hardness and tensile strength of the SiC microstructure implemented under optimum process conditions are 94.5 GPa, 10.5 GPa and 11.7 N/min, respectively. Consequently, the SiCN microstructure proposed in this work is very suitable for super-high temperature MEMS application due to very simple fabrication process and the potential possiblity of sophisticated multlayer or 3D microstructures as well as its good mechanical properties.

• Korean Chemical Engineering Research
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• v.57 no.2
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• pp.177-184
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• 2019

Non-fluorinated water repellent coating solutions were obtained using methyltrimethoxysilane (MTMS) and trimethylethoxysilane (TMES) as precursors. The solutions were spin-coated on a cold-rolled steel sheet and cured thermally to prepare water repellent coating films. During this process, the effect of molar ratio of TMES/MTMS was studied for the hydrophobic properties of the coating films. Hydrophobic properties of coating films were characterized using contact angle measurement, surface morphology analysis and infrared spectroscopy. When the molar ratio of TMES/MTMS was varied from 0 to 30, the contact angle of the un-coated cold-rolled steel sheet was $30^{\circ}$, whereas when the molar ratio of TMES/MTMS was 1, the contact angle increased to $104^{\circ}$ and water repellency was significantly improved. In the case of TMES/MTMS molar ratios of 10, 15, 25 and 30, the contact angles of coating films showed $109^{\circ}$, $114^{\circ}$, $117^{\circ}$ and $144^{\circ}$, respectively. At this time, the hydrophobicity of the coating films was improved by the increase of the surface roughness and the content of the methyl component at the coating surface. In particular, when the molar ratio of TMES/MTMS was 30, the overall surface roughness was greatly increased due to the presence of surface particles as well as the water repellency due to methyl groups of TMES, resulting in super hydrophobicity of $144^{\circ}$.

• Tribology and Lubricants
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• v.24 no.5
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• pp.255-263
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• 2008

Adhesion tests were conducted to investigate the adhesion characteristics between mold and thermoplastic polymer film. Coating of anti-sticking layer (ASL), a kind of polymer material, imprint pressure, and separation velocity were considered as the process conditions. A piece of fused silica without patterns on its surface was used as a mold and the thermoplastic polymer films were made on Si substrate by spin-coating the commercial polymer solution such as mr-I PMMA and mr-I 7020. The ASL was derived from (1H, 1H, 2H, 2H - perfluorooctyl) trichlorosilane($F_{13}$-OTS) and coated on the fused silica mold in vapor phase. The pull-off force was measured in various process conditions and the surfaces of the mold and the polymer film were observed after separation. It was found that the adhesion characteristics between the mold and the thermoplastic polymer film and the release performance of ASL were changed according to the process conditions. The ASL was effective to reduce the pull-off force and the damage of polymer film. In cases of the mold coated with ASL, the pull-off force did not depend on imprint pressure and separation velocity.

• Journal of Information Display
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• v.9 no.3
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• pp.8-11
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• 2008

A novel non-alkoxide sol-gel process for synthesizing Ga-doped ZnO thin film on glass was derived for possible use as a transparent electrode in flat-panel displays, using zinc acetate dehydrate as the starting material. The structural and electrical properties of thin films have been characterized as functions of Ga addition and post-heat-treatments. Their carrier density, Hall mobility, and optical transmittance were measured and discussed herein to explain the characteristics of the sol-gel-derived Ga-doped ZnO thin film on glass.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.42-42
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• 2009

To make up for the disadvantages of PVA gate, we blend PVP(20% wt) with PVA(5% wt) as a gate material. The best ratio for the mixture was 5:5, PVP-PVA blended gate used MIM structure showed better performance in leakage current and capacitance. PVP-PVA blended gate was fabricated by spin-coating process and pentacene was used as an organic TFT channel layer by thermal evaporation. Overall OTFT performance has also increased as PVP-PVA blended gate has relatively lower leakage current and higher capacitance than pure PVA gate has.

• Journal of the Microelectronics and Packaging Society
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• v.3 no.1
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• pp.33-40
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• 1996

MOD법에 의해 BST박막을 제조하고 전기적 특성을 측정함으로써 마이크로 회로에 적용가능성을 타진하였다. MOD 공정의 선구물질로서 barium neodecanoate, strontium 2-ethylhexanoate 및 titanium dimethoxy 야-2-ethylheanoate를 합성하였다, 합성된 선구물 질들을 Ba0.5Sr0.5TiO3가 되도록 화학양론적으로 혼합하여 공통용매인 p-xylene에 녹인다음 기판위에 spin coating 방법으로 박막을 형성하여 건조하고 소성하였다. 사용된 기판은 ITO/glass, Pt/SiO2/Si, Pt/Ti/SiO2/Si 및 Pt foil을 사용하였다. 소성 속도를 빨리했을 경우 소성속도를 느리게 했을때에 비하여 훨씬 균일하고 치밀한 박막을 얻을수 있었다, 여러 가 지 제조조건의 변화에 따른 유전상수 I-V 특성 및 C-V 측성 등의 전기적 특성을 측정하고 고찰하였다.