• Proceedings of the Materials Research Society of Korea Conference
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• 2001.05a
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• pp.81-81
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• 2001

No Abstract (See Full-text)

• Proceedings of the Korean Vacuum Society Conference
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• 2003.02a
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• pp.140-140
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• 2003

• Proceedings of the Korean Society of Crop Science Conference
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• 1994.10a
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• pp.62-63
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• 1994

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.12 no.5
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• pp.247-252
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• 2002

$(Pb_{1-x}La_x)TiO_3$ (x = 0.1) thin films were prepared on ITO-coated glass substrates by metal organic chemical vapor deposition using ultrasonic spraying. Effects of the post-annealing and the seeding layer on crystallization, microstructures and electrical properties of thin films were investigated. Dielectric constants of films increased due to the modification of crystallization and the changing of a surface morphology by applying the post-annealing. In addition, as the application of PT seed- ing layer offered nucleation sites to PLT thin films, electrical properties of films were enhanced by the increase of crys-tallinity and grain size. The dielectric constant of the films post-heated for 60 min and with a seeding layer was 213 at 1 kHz.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.268-269
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• 2005

YBCO 박막형 초전도체(coated conductor) 제조를 위해서는 여러 층의 완충층이 필요하다. 현재 일반적인 완충층의 구조는 seed layer로써 $Y_2O_3$, diffusion barrier로 YSZ, capping layer로 $CeO_2$가 사용되고 있다. 특히, capping layer로 $CeO_2$는 YBCO와 lattice mismatch가 매우 우수한 산화물로 이용되고 있다 본 연구에서는 $CeO_2$ capping layer가 증착 방법에 따라 그 위에 증착되어지는 초전도층의 특성에 어떤 영향을 미치는지 연구하였다. $CeO_2$를 thermal evaporation과 PLD (pulsed laser deposition) 증착 방법으로 증착 한 후 그 위에 PLD 방법으로 YBCO를 증착하여 coated conductor의 성능을 평가하였다.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.212-212
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• 2003

Many of the spin valve multilayer structures with FeMn as antiferromagnetic layer consist of a NiFe/FeMn/NiFe trilayer where the bottom NiFe layer is the seed layer to facilitate the growth of (111) gama-FeMn antiferromagnetic phase and the top NiFe layer forms the pinned layer[1], In this study, exchange bias of bottom NiFe layer has been investigated as functions of thicknesses of top and bottom NiFe in NiFe/FeMn/NiFe, prepared by rf magnetron sputtering, MH-loop was measured by vibration sample magnetometer (VSM). Two hysteresis loops are corresponded to bottom and top layers, similar to reported loops in spin valve structure. Exchange bias of bottom NiFe could be induced by the interfacial coupling between bottom NiFe and FeMn. But those coupling are strongly dependent on the top and bottom NiFe thicknesses, revealing anomalous character ul exchange bias of bottom NiFe layer.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.6
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• pp.2979-2995
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• 2017

In recent years, there has been an increasing number of studies focused on identifying a set of spreaders to maximize the influence of spreading in complex networks. Although the k-core decomposition can effectively identify the single most influential spreader, selecting a group of nodes that has the largest k-core value as the seeds cannot increase the performance of the influence maximization because the propagation sphere of this group of nodes is overlapped. To overcome this limitation, we propose a neighborhood coreness cover and discount heuristic algorithm named "NCCDH" to identify a set of influential and decentralized seeds. Using this method, a node in the high-order shell with the largest neighborhood coreness and an uncovered status will be selected as the seed in each turn. In addition, the neighbors within the same shell layer of this seed will be covered, and the neighborhood coreness of the neighbors outside the shell layer will be discounted in the subsequent round. The experimental results show that with increases in the spreading probability, the NCCDH outperforms other algorithms in terms of the affected scale and spreading speed under the Susceptible-Infected-Recovered (SIR) and Susceptible-Infected (SI) models. Furthermore, this approach has a superior running time.

• Journal of Sensor Science and Technology
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• v.17 no.3
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• pp.183-187
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• 2008

A sub-ppm level MEMS gas sensor that can be used for the detection of formaldehyde (HCHO) is presented. It is realized by using a zinc oxide (ZnO) thin-film material with a Ni-seed layer as a sensing material and by bulk micromachining technology. To enhance sensitivity of the MEMS gas sensor with Ni-seed layer was embedded with ZnO sensing material and sensing electrodes. As experimental results, the changed sensor resistance ratio for HCHO gas was 9.65 % for 10 ppb, 18.06 % for 100 ppb, and 35.7 % for 1 ppm, respectively. In addition, the minimum detection level of the fabricated MEMS gas sensor was 10 ppb for the HCHO gas. And the measured output voltage was about 0.94 V for 10 ppb HCHO gas concentration. The noise level of the fabricated MEMS gas sensor was about 50 mV. The response and recovery times were 3 and 5 min, respectively. The consumption power of the Pt micro-heater under sensor testing was 184 mW and its operating temperature was $400^{\circ}C$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.632-635
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• 2001

Microcrystalline Si films have been deposited by using five W-wire filaments of 0.5 mm diameter for hot-wire chemical vapor deposition (HWCVD). We compared the HWCVD grown films with the film exposed to transformer couple plasma system for the modification of seed layer. W-wire filament temperature was maintained below 1600$^{\circ}C$ to avoid metal contamination by thermal evaporation at the filament. Deposition conditions were varied with H$_2$dilution ratio, with and without plasma treatment. From the Raman spectra analysis, we observed that the film crystallization was strongly influenced by the H$_2$dilution ratio and weakly depended on the distance between the wire and a substrate. We were able to achieve the crystalline volume fraction of about 70% with an SiH$_4$/H$_2$ratio of 1.3%, a wire temperature of 1514$^{\circ}C$, a substrate separation distance of 4cm, and a chamber pressure of 38 mTorr. We investigated the influence of ${\mu}$c-Si film properties by using a plasma treatment. This article also deals with the influence of the H$_2$dilution ratio in crystallization modification.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.12-12
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• 2008

Ruthenium is one of the noble metals having good thermal and chemical stability, low resistivity, and relatively high work function(4.71eV). Because of these good physical, chemical, and electrical properties, Ru thin films have been extensively studied for various applications in semiconductor devices such as gate electrode for FET, capacitor electrodes for dynamic random access memories(DRAMs) with high-k dielectrics such as $Ta_2O_5$ and (Ba,Sr)$TiO_3$, and capacitor electrode for ferroelectric random access memories(FRAMs) with Pb(Zr,Ti)$O_3$. Additionally, Ru thin films have been studied for copper(Cu) seed layers for Cu electrochemical plating(ECP) in metallization process because of its good adhesion to and immiscibility with Cu. We investigated Ru thin films by thermal ALD with various deposition parameters such as deposition temperature, oxygen flow rate, and source pulse time. Ru thin films were grown by ALD(Lucida D100, NCD Co.) using RuDi as precursor and $O_2$ gas as a reactant at 200~$350^{\circ}C$.