• Title/Summary/Keyword: substrate

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Bridge-type formation of iridium-catalyzed carbon nanofibers across the Gap on MgO substrate and their electrical properties

  • Kim, Kwang-Duk;Kim, Sung-Hoon;Kim, Nam-Seok
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.16 no.5
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    • pp.198-202
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    • 2006
  • We could achieve the bridge-type formation of the iridium-catalyzed carbon nanofibers across the gap on the MgO substrate using microwave plasma enhanced chemical vapor deposition method. On the plane surface area of the MgO substrate, the iridium-catalyzed carbon nanofibers were grown as a lateral direction to the substrate. The bridge-type formation and/or the lateral growth of the iridium-catalyzed carbon nanofibers were interconnected with each other. Finally, they could form an entangled network having the bridge-type formation of the carbon nanofibers across the gap on the substrate and the laterally-grown carbon nanofibers on the plane surface area of the substrate. The entangled network showed the semiconductor electrical characteristics.

Deposition of Carbon Thin Film using Laser Ablation and Its Field Emission Properties (레이저 증착법에 의한 탄소계 박막의 구조 및 전계방출특성)

  • ;Kenjiro Oura
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.15 no.7
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    • pp.634-639
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    • 2002
  • Using laser ablation technique carbon thin films were deposited on Si(100) substrate as a function of substrate temperature. In this study, the surface morphologic, structural and field emission properties of these carbon thin films were investigated using Raman spectroscopy, scanning electron microscopy, and a diode technique, respectively. With increasing of the substrate temperature, the surface morphologies were changed significantly. Moreover, the intensity of D-band and the full width at half maximum of these bands were dependent on substrate temperatures. As the substrate temperature was increased, the field emission properties were improved. As the result, we find that the field emission properties of the films were changed significantly with the substrate temperature and structural features of carbon than films.

The study of crystallization to Si films deposited using a sputtering method on a Mo substrate (Mo기판 위에 sputtering 법으로 성장된 Si 박막의 결정화 연구)

  • 김도영;고재경;박중현;이준신
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07a
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    • pp.36-39
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    • 2002
  • Polycrystalline silicon (poly-Si) thin film transistor (TFT) technology is emerging as a key technology for active matrix liquid crystal displays (AMLCD), allowing the integration of both active matrix and driving circuit on the same substrate (normally glass). As high temperature process is not used for glass substrate because of the low softening points below 450$^{\circ}C$. However, high temperature process is required for getting high crystallization volume fraction (i.e. crystallinity). A poly-Si thin film transistor has been fabricated to investigate the effect of high temperature process on the molybdenum (Mo) substrate. Improve of the crystallinity over 75% has been noticed. The properties of structural and electrical at high temperature poly-Si thin film transistor on Mo substrate have been also analyzed using a sputtering method

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GaN Base Blue LED on Patterned Sapphire Substrate by Wet Etching (습식식각 방법으로 제작한 패턴 형성 사파이어 기판을 가지는 GaN계 청색 LED)

  • Kim, Do-Hyung;Yi, Yong-Gon;Yu, Soon-Jae
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.24 no.1
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    • pp.7-11
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    • 2011
  • Sapphire substrate was patterned by a selective chemical wet etching technique, and GaN/InGaN structures were grown on this substrate by MOVPE (Metal Organic Vapor Phase Epitaxy). The surface of grown GaN on patterned sapphire substrate (PSS) has good morphology and uniformity. The patterned sapphire substrate LED showed better light output than conventional LED that improvement 50%. We think these results come from enhancement of internal quantum efficiency by decrease of threading dislocation and increase of light extraction efficiency. Also these LED showed more uniform emission distribution in angle than conventional LED.

A Simple and Accurate Parameter Extraction Method for Substrate Modeling of RF MOSFET (간단하고 정확한 RF MOSFET의 기판효과 모델링과 파라미터 추출방법)

  • 심용석;양진모
    • Proceedings of the Korea Society of Information Technology Applications Conference
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    • 2002.11a
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    • pp.363-370
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    • 2002
  • A substrate network model characterizing substrate effect of submicron MOS transistors for RF operation and its parameter extraction with physically meaningful values are presented. The proposed substrate network model includes a single resistance and inductance originated from ring-type substrate contacts around active devices. Model parameters are extracted from S-parameter data measured from common-bulk configured MOS transistors with floating gate and use where needed with out any optimization. The proposed modeling technique has been applied to various-sized MOS transistors. Excellent agreement the measurement data and the simulation results using extracted substrate network model up to 30GHz.

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Mechanical and electro-mechanical analysis in differently stabilized GdBCO coated conductor tapes with stainless steel substrate

  • Nisay, Arman R.;Shin, Hyung-Seop
    • Progress in Superconductivity and Cryogenics
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    • v.15 no.2
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    • pp.29-33
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    • 2013
  • The understanding of the strain dependence of critical current, $I_c$, in the reversible region is important for the evaluation of the performance of coated conductor (CC) tapes in practical applications. In this study, the stress/strain tolerance of $I_c$ in GdBCO CC tapes with stainless steel substrate stabilized by additional Cu and brass laminate was analyzed quantitatively through $I_c$-strain measurement at 77 K under self-field. The variation in irreversible strain limits of CC tapes by the addition of stabilizing layers was analyzed through the consideration of the pre-strain induced on the GdBCO coating film. The results were then compared with the ones previously reported for GdBCO CC tapes with Hastelloy substrate. As a result, GdBCO CC tapes with stainless steel substrate showed much higher strain tolerance of $I_c$ as compared with those adopting Hastelloy substrate.

The Low Temperature Laser Treatment of Sealing Glass Substrate for ECL (ECL용 유리기판의 레이저 저온 실링처리)

  • Choi, Hye-Su;Park, Cha-Soo;Gwak, Dong-Joo;Sung, Youl-Moon
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.1134-1135
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    • 2015
  • In this paper, we reported fabrication of sealing the glass substrate using laser treatment at low temperature for electrochemical luminescence (ECL) cell. The laser treatment at temperature is using laser diode. The glass substrate sealing by laser treatment tested at 1-5 W, 1-5 mm/s for builted and tested. The sealing laser treatment method will allow associate coordination between the two glass substrate was enclosed. The effect of laser treatment to sealing the glass substrate was found to have cracks and air gap at best thickness of about $845-780{\mu}m$ for condition 5 W, 1-5 mm/s. The surface of sealing was roughness which was not influent to electrodes So, it is more effective viscosity between two glasses substrate.

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Effect of the Substrate Temperature on the Copper Oxide Thin Films

  • Park, Ju-Yeon;Gang, Yong-Cheol
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.08a
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    • pp.71-71
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    • 2010
  • Copper oxide thin films were deposited on the p-type Si(100) by r.f. magnetron sputtering as a function of different substrate temperature. The deposited copper oxide thin films were investigated by atomic force microscopy (AFM), scanning electron microscopy (SEM), spectroscopic ellipsometry (SE), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The SEM and SE data show that the thickness of the copper oxide films was about 170 nm. AFM images show that the surface roughness of copper oxide films was increased with increasing substrate temperature. As the substrate temperature increased, monoclinic CuO (111) peak appeared and the crystal size decreased while the monoclinic CuO (-111) peak was independent on the substrate temperature. The oxidation states of Cu 2p and O 1s resulted from XPS were not affected on the substrate temperature. The contact angle measurement was also studied and indicated that the surface of copper oxide thin films deposited high temperature has more hydrophobic surface than that of deposited at low temperature.

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Monte Carlo Simulation of Interacting Liquid Crystal and Substrate using Rigid Model Molecules

  • Hyodo, Yosuke;Koda, Tomonori;Momoi, Yuichi;Kim, Woo-Yeol;Nishioka, Akihiro;Miyata, Ken;Murasawa, Go
    • Journal of Information Display
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    • v.8 no.4
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    • pp.1-4
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    • 2007
  • In the present study, we propose Monte Carlo simulation that takes into consideration the interface phenomena between liquid crystal and substrate. We use rigid model molecules of liquid crystal and substrate. Interface is generated using potential field that induces decomposition of molecules. We use hard spherocylinders as model liquid crystal molecules. Substrate is modeled as region composed of shorter spherocylinders. Our results show that there is a case in which nematic order is reinforced in the vicinity of rubbed substrate.

Effects of Composition of Substrate on Transverse Rupture Strength and Bonding Strength of Cemented Carbide Coated with Titanium Carbide by CVD Process (화학흡착(CVD)법에 의한 TiC 흡착 시 모재가 피복 길항합금의 항면력 및 접착력에 미치는 영향)

  • Lee, Geon-U;O, Jae-Hyeon
    • Journal of the Korean institute of surface engineering
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    • v.24 no.1
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    • pp.8-8
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    • 1991
  • To investigate the effects of substrate on transverse-rupture strength(TRS) and bonding strength between substrate and TiC layer coated by CVD, two kinds of substrate (substrate A:WC-9.5wt%Co-MC*[low C], substrate B: WC-6wt% Co-MC*[high C] were studied in terms of Cobalt and C contents respectively. For preparation of test samples the coating parameters of deposition time, deposition temperature and deposition pressure were varied. The result show that the carbon contents in substrates have greater effects on the TRS of the CVD TiC coated cemented carbide than Co contents in substrates.