• Title/Summary/Keyword: metal/insulator

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Metal-insulator Transition in Low Dimensional $La_{0.75}Sr_{0.25}VO_3$ Thin Films

  • Huynh, Sa Hoang;Dao, Tran M.;Mondal, Partha S.;Takamura, Y.;Arenholz, E.;Lee, Jai-Chan
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2011.10a
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    • pp.19.1-19.1
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    • 2011
  • We report on the metal-insulator transition that occurs as a function of film thickness in ultrathin $La_{0.75}Sr_{0.25}VO_3$ films. The metal-insulator transition displays a critical thickness of 5 unit cell. Above the critical thickness, metallic films exhibit a temperature driven metal-insulator transition with weak localization behavior. With decreasing film thickness, oxygen octahedron rotation in the films increases, causing enhanced electron-electron correlation. The electron-electron correlations in ultrathin films induce the transition from metal to insulator in addition to Anderson localization.

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Improvement of Electrical Properties of Diamond MIS (Metal-Insulator- Semiconductor) Interface by Gate Insulator and Application to Metal-Insulator- Semiconductor Field Effect Transistors (게이트 절연막에 의한 다이아몬드 MIS (Metal-Insulator-Semiconductor) 계면의 전기적 특성 개선과 전계효과 트랜지스터에의 응용)

  • Yun, Young
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.14 no.6
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    • pp.648-654
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    • 2003
  • Diamond MIS(Metal-Insulator-Semiconductor) diodes and MISFETs(Metal-Insulator-Semiconductor Field Effect Transistors) were fabricated by employing various fluorides as gate insulator, and their electrical properties were closely investigated by means of C-V measurements. The A1/BaF$_2$/diamond MIS structure exhibited outstanding electrical properties. The MIS diode showed a very low surface state density of ∼10$\^$10//$\textrm{cm}^2$ eV near the valence band edge, and the observed effective mobility(${\mu}$$\_$eff/) of the MISFET was 400 $\textrm{cm}^2$/Vs, which is the highest value obtained until now in the diamond FET. From the chemiphysical point of view, the above result might be explained by the reduction of adsorbed-oxygen on the diamond surface via strong chemical reaction by the constituent Ba atom in the insulator during the film deposition(Oxygen-Gettering Effect).

Effect of Bottom Electrode on Resistive Switching Voltages in Ag-Based Electrochemical Metallization Memory Device

  • Kim, Sungjun;Cho, Seongjae;Park, Byung-Gook
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.16 no.2
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    • pp.147-152
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    • 2016
  • In this study, we fabricated Ag-based electrochemical metallization memory devices which is also called conductive-bridge random-access memory (CBRAM) in order to investigate the resistive switching behavior depending on the bottom electrode (BE). RRAM cells of two different layer configurations having $Ag/Si_3N_4/TiN$ and $Ag/Si_3N_4/p^+$ Si are studied for metal-insulator-metal (MIM) and metal-insulator-silicon (MIS) structures, respectively. Switching voltages including forming/set/reset are lower for MIM than for MIS structure. It is found that the workfunction different affects the performances.

Charge Carrier Behaviour of Metal-Polymer Interface (금속-고분자 계면에서의 전하의 거동)

  • Yun, Ju-Ho;Choi, Yong-Sung;Ahn, Seong-Soo;Moon, Jong-Dae;Lee, Kyung-Sup
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.06a
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    • pp.373-374
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    • 2008
  • Insulating polymers and their composites have been widely used in various electric apparatus or cables. Recently, the effects of interfaces (metal/insulator or insulator/insulator interfaces) on electrical insulation have attracted much attention. However, interfacial phenomena in actual insulation systems and their physical backgrounds are not well understood yet. In this paper, the behaviour of charge carriers near the metal/polymer interface and its effects on conduction and breakdown phenomena are discussed. The metal/polymer interface strongly affects carrier injection, space charge formation and breakdown phenomena. Based on their experimental results, the physical backgrounds of the interfacial phenomena are explained.

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Electric simulation of composite insulator with aspect of metal (Composite insulator의 금구류 형상변화에 따른 전계특성)

  • Woo, B.C.;Kang, D.P.
    • Proceedings of the KIEE Conference
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    • 1997.07d
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    • pp.1443-1445
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    • 1997
  • This paper presents an analysing method to find out an optimum metal shape for insulation strength of SCI(Silicone Composite Insulator). Using finite element method, the interested parameters of the configuration such as a aspect of metal/silicone composite and a material properties are investigated and derived a thread of optimum design parameters.

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Solution-Processed Gate Insulator of Ethylene-Bridged Silsesquioxnae for Organic Field-Effect Transistor (OTFT용 용액공정의 에틸렌-브리지드 실세스퀴옥산 게이트 절연체)

  • Lee, Duck-Hee;Jeong, Hyun-Dam
    • Journal of Integrative Natural Science
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    • v.3 no.1
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    • pp.7-18
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    • 2010
  • Ethylene-bridged silsesquioxane resins were synthesized from two monomers: 1,2-bis(trimethoxysilyl)ethane and methyltrimethoxysilane. The silsesquioxane thin films were spin-coated from the copolymerized resins on silicon wafer. Metal insulator metal (MIM), metal insulator semiconductor (MIS) devices were utilized to investigate the electrical properties of the copolymerized thin films. As the films were inserted as gate insulator in the OTFT devices, the field effect mobilitites were evaluated by employing Poly(3-hexylthiophene) (P3HT) as organic semiconductor, which shows that their dielectric properties and mobility values are dependent on the molecular structures and Si-OH concentration involving in the films.

Development of Compensation-Type Fire Detector Using Metal-Insulator-Transition Critical-Temperature Sensor (금속-절연체 전이 임계온도센서를 이용한 보상식 화재 감지기 개발)

  • Jung, Sun-Kyu;Kim, Hyun-Tak
    • Fire Science and Engineering
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    • v.28 no.1
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    • pp.26-30
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    • 2014
  • A Compensation-type fire detector (CFD) is operated with two functions of a differential-temperature detector and as a fixed-temperature detector. The differential-temperature detector observes a rate of temperature increase, and the fixed-temperature detector measures a given fixed temperature. The differential-temperature detector does not observe the outbreak of fire in slowly increasing temperature conditions, whereas the fixed-temperature detector is not able to observe the outbreak of fire in conditions under predetermined temperature level. We developed a CFD to compensate for weaknesses of both detectors. To compensate for the disadvantages, a sensor of the sensor metal-insulator-transition critical-temperature sensor was used. Temperature coefficient of resistance is the sensitivity for sensor. At $55^{\circ}C$, temperature coefficient of resistance of metal-insulator-transition critical-temperature sensor was 14.15%. Temperature coefficient of resistance of thermistor was about 0.5%. This CFD was operated as two ways that fixed-temperature detector and differential-temperature detector in one sensor.

Effects of One-Time Post-Annealing(OPTA) Process on the Electrical Properties of Metal- Insulator-Metal Type Thin-Film

  • Lee, Myung-Jae;Chung, Kwan-Soo
    • Proceedings of the IEEK Conference
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    • 2001.06b
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    • pp.273-276
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    • 2001
  • The origin of image-slicking in metal-insulator-metal type thin-film-diode(TFD) LCDs is the asymmetric current-voltage(I-V) characteristic of TFD element. we developed that MIM-LCDs have reduced-image-sticking and perfect symmetry characteristic. One-Time Post-Annealing (OPTA) heat treatment process was introduced to reduce the asymmetry and shift of the I-V characteristics, respectively. OPTA means that the whole layers of lower metal, insulator, and uuper metal are annealed at one time. The treatment temperatures and fabricated process of TFD element were under foot. Also, this low temperature fabricated process allows the application of plastic substrates.

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