• Title/Summary/Keyword: Barrier Metal

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Characteristics of Ni/SiC Schottky Diodes Grown by ICP-CVD

  • Gil, Tae-Hyun;Kim, Han-Soo;Kim, Yong-Sang
    • KIEE International Transactions on Electrophysics and Applications
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    • v.4C no.3
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    • pp.111-116
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    • 2004
  • The Ni/SiC Schottky diode was fabricated with the $\alpha$-SiC thin film grown by the ICP-CVD method on a (111) Si wafer. $\alpha$-SiC film has been grown on a carbonized Si layer in which the Si surface was chemically converted to a very thin SiC layer achieved using an ICP-CVD method at $700^{\circ}C$. To reduce defects between the Si and $\alpha$-SiC, the surface of the Si wafer was slightly carbonized. The film characteristics of $\alpha$-SiC were investigated by employing TEM (Transmission Electron Microscopy) and FT-IR (Fourier Transform Infrared Spectroscopy). Sputterd Ni thin film was used as the anode metal. The boundary status of the Ni/SiC contact was investigated by AES (Auger Electron Spectroscopy) as a function of the annealing temperature. It is shown that the ohmic contact could be acquired beyond a 100$0^{\circ}C$ annealing temperature. The forward voltage drop at 100A/cm was I.0V. The breakdown voltage of the Ni/$\alpha$-SiC Schottky diode was 545 V, which is five times larger than the ideal breakdown voltage of the silicon device. As well, the dependence of barrier height on temperature was observed. The barrier height from C- V characteristics was higher than those from I-V.

Fabrication of Paper-based Biosensor Chip Using Polydimethylsiloxane Blade Coating Method (PDMS 블레이드 코팅법을 이용한 종이-기반 바이오센서칩 제작)

  • Jeong, Heon-Ho;Park, Chami
    • Korean Chemical Engineering Research
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    • v.59 no.1
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    • pp.100-105
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    • 2021
  • This paper proposes the polydimethylsiloxane (PDMS) blade coating method for fabrication of paper-based analytical device (PAD) that is able to monitor the disease diagnosis and progress without special analytical equipment. The mold that has PAD design is easily modified by using laser cutting technique. And the fabricated mold is used for hydrophobic barrier formation by blade coating. We have optimized the stable formation of PDMS hydrophobic barrier as blade coating condition, which is established by analyzing the structure of the PDMS hydrophobic barrier and change of hydrophilic channel size as thickness of the ink and contact time with the chromatography paper. Based on optimal condition, we demonstrate that PAD as biosensor can apply to detect protein, glucose, and metal ion without special analysis equipment.

고효율 저가형 결정질 실리콘 태양전지에 적용될 Ni/Cu 전극 및 Ni silicide 형성에 대한 연구

  • Kim, Min-Jeong;Lee, Su-Hong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.11a
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    • pp.260-260
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    • 2009
  • In high-efficiency crystalline silicon solar cell, If high-efficiency solar cells are to be commercialized, It is need to develop superior contact formation method and material that can be inexpensive and simple without degradation of the solar cells ability. For reason of plated metallic contact is not only high metallic purity but also inexpensive manufacture. It is available to apply mass production. Especially, Nickel, Copper are applied widely in various electronic manufactures as easily formation is available by plating. Ni is shown to be a suitable barrier to Cu diffusin as well as desirable contact metal to silicon. Nickel monosilicide has been suggested as a suitable silicide due to its lower resistivitym lower sintering temperature and lower layer stress than $TiSi_2$. In this paper, Nickel as a seed layer and diffusion barrier is plated by electroless plating to make nickel monosilicide.

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Thickness dependency of MAHONOS ($Metal/Al_2O_3/HfO_2/SiO_2/Si_3N_4/SiO_2/Si$) charge trap flash memory

  • O, Se-Man;Yu, Hui-Uk;Kim, Min-Su;Lee, Yeong-Hui;Jeong, Hong-Bae;Jo, Won-Ju
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.11a
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    • pp.34-34
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    • 2009
  • The electrical characteristics of tunnel barrier engineered charge trap flash (TBE-CTF) memory with $SiO_2/Si_3N_4/SiO_2/Si$ engineered tunnel barrier, $HfO_2$ charge trap layer and $Al_2O_3$ blocking oxide layer (MAHONOS) were investigated. The energy bad diagram was designed by using the quantum-mechanical tunnel model (QM) and then the CTF memory devices were fabricated. As a result, the best thickness combination of MAHONOS is confirmed. Moreover, not enhanced P/E speed (Program: about $10^6$ times) (Erase: about $10^4$ times) but also enhanced retention and endurance characteristics are represented.

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Elastic and inelastic electron tunneling characteristics in polyimide LB films (Polyimide LB막내의 탄성 및 비탄성 tunneling 전기전도특성)

  • ;;Mitsumasa Iwamoto
    • Electrical & Electronic Materials
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    • v.7 no.6
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    • pp.473-480
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    • 1994
  • The electron tunnel effect in polvimide LB films sandwiched between metal electrodes has been investigated in the present work by a study of both the elastic and inelastic tunneling components. By the results of elastic tunneling experiments in Au/Pl/Au tunneling junction, we can judge the height and thickness of tunnel barrier. The inelastic current in Inelastic Electron Tunneling Spectroscopy(IETS) is due to the interaction of the tunneling electron with the vibrational modes of the molecular species in the barrier. Measurements are done on Au/PI/Pb tunneling junctions. The spectra obtained are the second derivatives of the current-voltage characteristics of these junctions : specifically, d$^{2}$1/dV$^{2}$ as a function of voltage V. Because the energies measured by IETS can be directly compared to those measured by infrared and Raman spectroscopy, IR-RAS spectroscopy also measured for reference.

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Loss of Integrity: Impairment of the Blood-brain Barrier in Heavy Metal-associated Ischemic Stroke

  • Kim, Jeong-Hyeon;Byun, Hyeong-Min;Chung, Eui-Cheol;Chung, Han-Young;Bae, Ok-Nam
    • Toxicological Research
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    • v.29 no.3
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    • pp.157-164
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    • 2013
  • Although stroke is one of the leading causes of death and disability worldwide, preventive or therapeutic options are still limited. Therefore, a better understanding of the pathophysiological characteristics of this life-threatening disease is urgently needed. The incidence and prevalence of ischemic stroke are increased by exposure to certain types of xenobiotics, including heavy metals, suggesting the possible toxicological contribution of these compounds to the onset or aggravation of stroke. Among the potential targets, we have focused on alterations to cerebral endothelial cells (CECs), which play important roles in maintaining the functional integrity of brain tissue.

Thermal cyclic characteristics of TBC/CoNiCrAlY thermal barrier coatings (TBC/CoNiCrAlY 용사코팅의 열싸이클 특성)

  • Kim Ui-Hyeon;Yu Geun-Bong
    • Proceedings of the KWS Conference
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    • 2006.05a
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    • pp.45-47
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    • 2006
  • The rotating components in the hot sections of land-based gas turbine are exposed to severe environments during several tens thousand operation hours at above $1100^{\circ}C$ operation temperature. To protect such components from high temperature oxidation, an intermediate bond coat is applied, typical of a MCrAlY-type metal alloy. This study is concerned with the thermal cyclic behavior of thermal barrier coatings. The MCrAlY bond coatings are deposited by HVOF (High Velocity Oxygen Fuel) method on a nickel-based superalloy (GTD-111). Thermal cyclic tests at $1100^{\circ}C$ in ambient air for various periods of time were used to evaluate the thermal cyclic resistance of the TBC coating. The microstructure and morphology of as-sprayed and of thermal cycled coatings were characterized by scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD).

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Fabrication of Nano Metal Compounds Using Porous Aluminum Oxide Films (기공성 알루미나 산화 피막을 이용한 나노 금속화합물의 제조)

  • Oh, Han-Jun;Jeong, Yong-Soo;Chi, Choong-Soo
    • Journal of Surface Science and Engineering
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    • v.43 no.5
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    • pp.248-254
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    • 2010
  • Porous $Al_2O_3$ film can be utilized as template for fabrication of nano-structured materials. Porous anodic alumina layer as template was prepared by anodization of aluminum in oxalic acid, and the pore diameter and barrier-type alumina layer can be controlled for proper anodizing parameter by widening process in $H_3PO_4$ solution. The $SiO_2$ nanodot and Ni nanowire was fabricated using anodic alumina template and their characteristics were investigated using SEM and TEM with EDS. Especially the growth mechanism of $SiO_2$ nanodot in alumina membrane compared with thinning of the alumina barrier layer during anodization was also investigated.

Schottky Barrier Field-Effect Transistor의 소자의 특성 및 성능 비교분석

  • Kim, Gyeong-Tae;Park, Hyeok-Jun;U, Ji-Yun;Park, Yeong-Min
    • Proceeding of EDISON Challenge
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    • 2017.03a
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    • pp.372-375
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    • 2017
  • Metal-oxide-semiconductor Field-Effect transistor (MOSFET)을 대체할 기술로서 제안된 Schottky Barrier MOSFET (SB-MOSFET)가 제시되고 있다. 본 연구에서는 SB-MOSFET와 MOSFET을 다양한 소자 파라미터를 변화시킴으로서 양자역학적 전하수송 계산을 바탕으로 특성을 분석한다. MOSFET과 SB-MOSFET은 채널 두께 ($T_{Si}$)가 감소함에 따라 전류량은 증가하고 SS와 DIBL은 증가하였고 Overlap에서는 SS와 DIBL이 커지고 Underlap에서는 작아짐을 보였고 SB-MOSFET는 특히 그 폭이 컸다. 또한 SB 높이가 낮을수록 SB-MOSFET의 전류량이 증가하고 SS는 감소하였고 마찬가지로 Source와 Drain doping concentration이 낮을수록 MOSFET의 전류량은 증가하고 SS는 감소하였다. MOSFET과 SB-MOSFET의 경향은 대체로 비슷하나 변화량의 차이 등이 있었다.

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Inclusion of Silicon Delta-doped Two-dimensional Electron Gas Layer on Multi-quantum Well Nano-structures of Blue Light Emitting Diodes

  • Kim, Keun-Joo
    • Transactions on Electrical and Electronic Materials
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    • v.5 no.5
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    • pp.173-179
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    • 2004
  • The influence of heavily Si impurity doping in the GaN barrier of InGaN/GaN multi-quantum well structures of blue light emitting diodes were investigated by growing samples in metal-organic chemical vapor deposition. The delta-doped sample was compared to the sample with the undoped barrier. The delta-doped sample shows the tunneling behavior and forms the energy level of 0.32 eV for tunneling and the photoemission of the 450-nm band. The photo-luminescence shows the blue-shifted broad band of the radiative transition due to the inclusion of Si delta-doped layer indicating that the delta doping effect acts to form the higher energy level than that of quantum well. The dislocation may provide the carrier tunneling channel and plays as a source of acceptor. During the tunneling of hot carrier, there was no light emission.