• Progress in Superconductivity and Cryogenics
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• v.9 no.4
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• pp.16-18
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• 2007

We report the results of MOD-processed YBCO coated conductors on the IBAD-MgO template. The precursor solution was coated on the $CeO_2-buffered$ IBAD-MgO template using a slot-die coating method, calcined at a temperature of $550^{\circ}C$, and fired at high temperatures for 2.5 h in a reduced oxygen atmosphere. The $J_C$ value of YBCO coated conductors was found to be very sensitive to the microstructure, and thus higher $J_C$ value could be achieved when the in-plane texture was higher and the difference in $T_{C,zero}$. was negligible. Optimally processed YBCO coated conductor exhibited $J_C$ value of $0.75MA/cm^2$ at 77 K in self-field, which might be due to somewhat depressed $T_{C,zero}$ of 87.3 K caused by possible $Sm^{3+}$ substitution on the $Ba^{2+}$ site.

• Journal of Sensor Science and Technology
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• v.18 no.3
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• pp.239-244
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• 2009

We fabricated nano-templates by low temperature BCP(block copolymer) process at 180 $^{\circ}C$, then we deposited 10 nm-thick $TiO_2$ layers with ALD(atomic layer deposition) at low temperature of 150 $^{\circ}C$. Through FE-SEM analysis, we confirmed the successful formation of the groove-type(width of crest : 30 nm, width of trough : 18 nm) and the cylinder-type(diameter : 10 nm, distance between hole : 25 nm) templates. Moreover, after $TiO_2$-ALD processing, we confirmed the deposition of the uniform nano layers of $TiO_2$ on the nano-templates. Through AFM analysis, the pitches of the crest-through(in groove-type) and hole-hole(in cylinder-type) were the same before and after $TiO_2$-ALD processing. In addition, we indirectly determined the existence of the uniform $TiO_2$ layers on nano-templates as the surface roughness decreased drastically. We successfully fabricated nano-template at low temperature and confirmed that the three-dimensional nano-structure for sensor application could be achieved by $TiO_2$-ALD processing at extremely low temperature of 150 $^{\circ}C$.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.814-817
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• 2010

AAO thin films prepared by a two-step anodization process have pores that are uniform in diameter, highly ordered, and perfectly vertical with respect to the plane of the nano template. Further, the pore size and interpore distance can be easily controlled by varying the anodizing voltage and acid electrolyte. When metals are electrochemically deposited in the pores, metal nanowires that are highly ordered and uniform in diameter are formed in each pore.

• Food Engineering Progress
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• v.14 no.1
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• pp.49-53
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• 2010

Surface plasmon resonance (SPR) which is utilized in thin film refractometry-based sensors has been concerned on measurement of physical, chemical and biological quantities because of its high sensitivity and label-free feature. In this paper, an application of SPR to detection of alcohol content in wine and liquor was investigated. The result showed that SPR sensor had high potential to evaluate alcohol content. Nevertheless, food industry may need SPR sensor with higher sensitivity. Herein, we introduced a nano-technique into fabrication of SPR chip to enhance SPR sensitivity. Using Langmuir-Blodgett (LB) method, gold film with nano-structured surface was devised. In order to make a new SPR chip, firstly, a single layer of nano-scaled silica particles adhered to plain surface of gold film. Thereafter, gold was deposited on the template by an e-beam evaporator. Finally, the nano-structured surface with basin-like shape was obtained after removing the silica particles by sonication. In this study, two types of silica particles, or 130 nm and 300 nm, were used as template beads and sensitivity of the new SPR chip was tested with ethanol solution, respectively. Applying the new developed SPR sensor to a model food of alcoholic beverage, the sensitivity showed improvement of 95% over the conventional one.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.3 s.47
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• pp.321-328
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• 2004

Nano silica ball and nano carbon ball are developed commercially by template synthesis method. Adsorption of unpleasant smelling substances such as ammonia, trimethylamine, acetaldehyde and methyl mercaptane onto nano carbon ball with hollow macroporous core/mesoporous shell structures, nano carbon ball, was investigated and compared with that onto odor adsorbent materials, activated carbon, commercially available. The adsorption and decomposition of malodor at nano carbon ball exhibited superior than those onto activated carbon. The physicochemical properties such as mesopore size distributions, large nitrogen BET specific surface area and large pore volume and decomposition of malodor were studied to interpret the predominant adsorption performance. The nano carbon ball is expected to be useful in many applications such as deodorizers, adsorbent of pollutants.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.633-636
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• 2005

Imprint lithography is a promising method for high-resolution and high-throughput lithography using low-cost equipment. As with other nanoimprint methods, ultraviolet-nanoimprint lithography (UV-NIL) resolution appears to be limited only by template resolution, and offers a significant cost of ownership reduction when compared to other next generation lithography (NGL) methods such as EUVL and 157 nm lithography. The purpose of this paper is to suggest optimum values of control parameters of Imprio 100 manufactured by Molecular Imprint, Inc., which is the first commercially available UV-NIL tool, for sound nanoimprint. UV-NIL experiments were performed on Imprio 100 to find dispensing recipe for avoiding air entrapment. Dispensing recipe related to residual layer thickness and uniformity was optimized and 40 nm thick residual layer was achieved.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.4
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• pp.8-13
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• 2015

In this study, we fabricated and characterized a nanostructured surface based on a plastic injection molding with a local mold heating (LMH) system. A metal mold core with a closed packed nano convex array (CVA) was achieved by integrated engineering procedures: (1) master template fabrication by anodic aluminum oxidation (AAO), (2) nickel electroforming (NE) process, and (3) post-processing by precision machining. The nickel mold core was utilized to replicate a surface with a closed packed nano concave-array (CCA) based on injection molding using cyclic olefin copolymer (COC) as a plastic material. In particular, an LMH system was introduced to enhance transcription quality of the nano structures by delaying solidification of molten polymer near the surface of the mold core.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.1971-1973
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• 2005

We fabricated an alumina membrane with nano-sized pore array by anodic oxidation using the thin film aluminum deposited on silicon wafer. It is important that the sample prepared by metal deposition method has a flat aluminum surface and a good adhesion between the silicon wafer and the thin film aluminum. The oxidation time was controlled by observation of current variation. The nano-sized pores with diameter of $60{\sim}120nm$ was obtained by $40{\sim}80$ voltage. The pore widening process was employed for obtaining the flat surface because the pores of the alumina membrane prepared by the fixed voltage method shows the structure of rough surface. Finally, the sample was immersed to the phosphoric acid with 0.1M concentration to etching the barrier layer. The sample will be applied to electronic sensors, field emission display, and template for nano- structure.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.220-221
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• 2007

금속 촉매 성장 (Metal-induced growth) 를 이용하여, 마이크로 사이즈의 결정질 (Microcrystalline) 박막 실리콘 (Silicon, Si)을 성장하였다. 금속 촉매로서는 코발트, 니켈, 코발트/니켈 복합물질(Co, Ni, or Co/Ni) 이 사용되었으며, 실리콘과 반응하여 실리사이드 (Silicide) 층을 형성한다. 이러한 실리사이드 층은 실리콘과 격자 거리가 유사하여 (Little lattice mismatch), 그 위에 실리콘 박막을 성장하기 위한 모체 (Template) 가 된다. XRD (X-ray diffraction) 분석을 통하여, 실리사이드 ($CoSi_2$ or $NiSi_2$) 의 형성과 성장된 박막 실리콘의 결정성을 연구하였다. 이러한 박막을 이용하여, 쇼트키 태양전지 (Schottky Solar cell) 에 응용하였다. 코발트/니켈 복합물질을 이용하였을 경우에 10.6mA/$cm^2$ 단락전류를 얻었으며, 이는 코발트만을 이용한 경우보다 10 배만큼 증가하였다. 이러한 실리사이드를 매개로한 박막 실리콘의 성장은 공정상에서의 열부담 (Thermal budget) 을 줄일 수 있으며, 대면적 응용에 큰 가능성을 가지고 있다.

• Journal of Ceramic Processing Research
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• v.13 no.spc2
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• pp.295-299
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• 2012

We investigated the crystal and the optical properties of GaN-based blue light emitting diodes (LEDs) which were simultaneously grown on c-plane (0001) and semipolar (11-22) GaN templates by using metal-organic chemical vapor deposition (MOCVD). The X-ray rocking curves (XRCs) full width at half maximums (FWHMs) of c-plane (0001) and semipolar (11-22) GaN templates were 275 and 889 arcsec, respectively. In addition, high-resolution X-ray ω-2θ scan showed that satellite peaks of semipolar (11-22) InGaN quantum-wells (QWs) was weaker and broader than that of c-plane (0001) InGaN QWs, indicating that the interface quality of c-plane (0001) QWs was superior to that of semipolar (11-22) QWs. Photoluminescence (PL) and electroluminescence (EL) results showed that the emission intensity and the FWHMs of polar c-plane (0001) LED were much higher and narrower than those of semipolar (11-22) LED, respectively. From these results, we believed that relative poor crystal quality of semipolar (11-22) GaN template might give rise to the poor interfacial quality of QWs, resulting in lower output power than conventional c-plane (0001) GaN-based LEDs.