• 제목/요약/키워드: Layered Perovskite

검색결과 90건 처리시간 0.026초

열처리 온도에 따른 Pt/SBT/Pt 커패시터의 피로특성 (Fatigue Properties of SBT capacitor with annealing temperatures)

  • 조춘남;김진사;오용철;신철기;최운식;김충혁;송민종;이준용
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 기술교육위원회 창립총회 및 학술대회 의료기기전시회
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    • pp.5-8
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    • 2001
  • The $Sr_{0.8}Bi_{2.4}Ta_{2}O_{9}(SBT)$ thin films are deposited on Pt-coated electrode$(Pt/TiO_{2}/SiO_{2}/Si)$ using RF magnetron sputtering method. With increasing annealing tempera ture from $600[^{\circ}C]$ to $850[^{\circ}C]$, Bi-layered perovskite phase was crystallized above $650[^{\circ}C]$. The dielectric constant is 213 at annealing temperature of $750[^{\circ}C]$ and dielectric loss have a stable value within 0.1. Leakage current density is $1.01{\times}10^{-8} A/cm^{2}$ at annealing temperature of $750[^{\circ}C]$ The fatigue characteristics of SBT thin films did not change up to $10^{10}$ switching cycles.

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열처리에 따른 SBT 캐패시터의 분극특성 (Polarization properties of SBT capacitor with annealing temperatures)

  • 조춘남;김진사;신철기;정일형;이상극;이동규;정동회;김충혁;이준웅
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 기술교육위원회 창립총회 및 학술대회 의료기기전시회
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    • pp.9-12
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    • 2001
  • The $Sr_{0.8}Bi_{2.4}Ta_2O_9(SBT)$ thin films are deposited on Pt-coated electrode($Pt/TiO_2/SiO_2/Si$) using RF magnetron sputtering method. With increasing post-annealing temperature from $600[^{\circ}C]$ to $850[^{\circ}C]$, Bi-layered perovskite phase was crystallized above $650[^{\circ}C]$. The maximum remanent polarization and the coercive electric field is 11.60[${\mu}C/cm^{2}$] 48[kV/cm] respectively. The leakage current density of SBT capacitor at post-annealing temperature of $750[^{\circ}C]$ is $1.01{\times}10^{-8}A/cm^2$ at 100[kV/cm]

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Ferroelectric and Structural Properties of Nd-substituted $Bi_4Ti_3O_{12}$ Thin Films Fabricated by MOCVD

  • Kang, Dong-Kyun;Park, Won-Tae;Kim, Byong-Ho
    • 한국반도체및디스플레이장비학회:학술대회논문집
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    • 한국반도체및디스플레이장비학회 2006년도 추계학술대회 발표 논문집
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    • pp.166-169
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    • 2006
  • A promising capacitor, which has conformable step coverage and good uniformity of thickness and composition, is needed to manufacture high-density non-volatile FeRAM capacitors with a stacked cell structure. In this study, ferroelectric $Bi_{3.61}Nd_{0.39}Ti_3O_{12}$ (BNT) thin films were prepared on $Pt(111)/Ti/SiO_2/Si$ substrates by the liquid delivery system MOCVD method. In these experiments, $Bi(ph)_3$, $Nd(TMHD)_3$ and $Ti(O^iPr)_2(TMHD)_2$ were used as the precursors and were dissolved in n-butyl acetate. The BNT thin films were deposited at a substrate temperature and reactor pressure of approximately $600^{\circ}C$ and 4.8 Torr, respectively. The microstructure of the layered perovskite phase was observed by XRD and SEM. The remanent polarization value (2Pr) of the BNT thin film was $31.67\;{\mu}C/cm^2$ at an applied voltage of 5 V.

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열처리 온도에 따른 Pt/SBT/Pt 캐패시터의 유전특성 (Dielectric Properties of SBT capacitor with annealing temperatures)

  • 조춘남;오용철;정일형;김진사;신철기;최운식;김충혁;이준웅
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 하계학술대회 논문집 C
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    • pp.1546-1548
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    • 2001
  • The $Sr_{0.8}Bi_{2.4}Ta_2O_9$(SBT) thin films are deposited on Pt-coated electrode(Pt/$TiO_2$/ $SiO_2$/Si) using RF magnetron sputtering method. With increasing annealing temperature from 600[$^{\circ}C$] to 850[$^{\circ}C$], Bi-layered perovskite phase was crystallized above 650[$^{\circ}C$]. The dielectric constant is 213 at annealing temperature of 750[$^{\circ}C$] and dielectric loss have a stable value within 0.1. Leakage current density is $1.01{\times}10^{-8}A/cm^2$ at annealing temperature of 750[$^{\circ}C$].

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비휘발성 메모리 소자응용을 위한 Eu 첨가량에 따른 BET 박막의 강유전 특성 (Ferroelectric Properties of Bi3.25La0.75Ti3O12 Thin Films with Eu Contents for Non-volatile Memory Device Application)

  • 김경태;김종규;우종창;김관하;김창일
    • 한국전기전자재료학회논문지
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    • 제20권3호
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    • pp.223-227
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    • 2007
  • The effect of Eu contents on the ferroelectric properties of $Bi_{4-x}Eu_xTi_3 O_{12}$ (BET) thin films has been investigated. Bismuth Europium titanate thin films with a Eu contents were prepared on the $Pt/Ti/SiO_2/Si$ substrate by metal-organic decomposition technique. The structure and the morphology of the films were analyzed using X-ray diffraction (XRD) and field emission scanning microscopy (FE-SEM), respectively. From the XRD analysis, it was found that BET thin films have polycrystalline structure, and the layered-perovskite phase is obtained when the Eu contents exceeds 0.2 (x > 0.2). Also, the ferroelectric characteristics of the BET thin films were found to be dependent on the Eu content. Particularly, the BET films doped with x = 0.75 show better ferroelectric properties (remanent polarization 2Pr = 60.99 C/$cm^2$ and only a little polarization fatigue up to $3.5{\times}10^9$ bipolar switching cycling) than those doped with other Eu contents.

플라즈마 스프레이 (Ca, Co)-Doped LaCrO3 코팅층의 치밀화 및 전기전도도 (Densification and Electrical Conductivity of Plasma-Sprayed (Ca, Co)-Doped LaCrO3 Coating)

  • 박희진;백경호
    • 한국재료학회지
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    • 제27권3호
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    • pp.155-160
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    • 2017
  • Doped-$LaCrO_3$ perovskites, because of their good electrical conductivity and thermal stability in oxidizing and/or reducing environments, are used in high temperature solid oxide fuel cells as a gas-tight and electrically conductive interconnection layer. In this study, perovskite $(La_{0.8}Ca_{0.2})(Cr_{0.9}Co_{0.1})O_3$ (LCCC) coatings manufactured by atmospheric plasma spraying followed by heat treatment at $1200^{\circ}C$ have been investigated in terms of microstructural defects, gas tightness and electrical conductivity. The plasma-sprayed LCCC coating formed an inhomogeneous layered structure after the successive deposition of fully-melted liquid droplets and/or partially-melted droplets. Micro-sized defects including unfilled pores, intersplat pores and micro-cracks in the plasma-sprayed LCCC coating were connected together and allowed substantial amounts gas to pass through the coating. Subsequent heat treatment at $1200^{\circ}C$ formed a homogeneous granule microstructure with a small number of isolated pores, providing a substantial improvement in the gas-tightness of the LCCC coating. The electrical conductivity of the LCCC coating was consequently enhanced due to the complete elimination of inter-splat pores and micro-cracks, and reached 53 S/cm at $900^{\circ}C$.

Fabrication of Nd-Substituted Bi4Ti3O12 Thin Films by Metal Organic Chemical Vapor Deposition and Their Ferroelectrical Characterization

  • Kim, Hyoeng-Ki;Kang, Dong-Kyun;Kim, Byong-Ho
    • 한국세라믹학회지
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    • 제42권4호
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    • pp.219-223
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    • 2005
  • A promising capacitor, which has conformable step coverage and good uniformity of thickness and composition, is needed to manufacture high-density non-volatile FeRAM capacitors with a stacked cell structure. In this study, ferroelectric $Bi_{3.61}Nd_{0.39}Ti_3O_{12}$ (BNdT) thin films were prepared on $Pt(111)/TiO_2/SiO_2/Si$ substrates by the liquid delivery system MOCVD method. In these experiments, $Bi(ph)_{3}$, $Nd(TMHD)\_{3}$ and $Ti(O^iPr)_{2}(TMHD)_{2}$ were used as the precursors and were dissolved in n-butyl acetate. The BNdT thin films were deposited at a substrate temperature and reactor pressure of approximately $600^{\circ}C$ and 4.8 Torr, respectively. The microstructure of the layered perovskite phase was observed by XRD and SEM. The remanent polarization value (2Pr) of the BNdT thin film was $31.67\;{\mu}C/cm^{2}$ at an applied voltage of 5 V.

비휘발성 메모리 소자응용을 위한 과잉 Bi 첨가에 따른 BLT 박막의 강유전 특성 (Ferroelectric Properties of Bi3.25La0.75 Ti3O12 Thin Films with Excess Bi Contents for Non-Volatile Memory Device Application)

  • 김경태;김창일;강동희;심일운
    • 한국전기전자재료학회논문지
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    • 제15권9호
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    • pp.764-769
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    • 2002
  • The effect of excess Bi contents on the ferroelectric properties of B $i_{3.25}$ L $a_{0.75}$ $Ti_3$ $O_{12}$ (BLT) thin films has been investigated. Bismuth lanthanum titanate thin films with excess Bi contents were prepared onto Pt/Ti/ $SiO_2$/Si substrate by metalorganic decomposition (MOD) technique. The structure and morphology of the films were analyzed using X-ray diffraction (XRD) and atomic force microscopy (AFM), respectively. From the XRD analysis, BLT thin films show polycrystalline structure and the layered-perovskite phase was obtained over 10% excess of Bi contents. As a result of ferroelectric characteristics related to the Bi content of the BLT thin film, the remanent polarization and dielectric constant decreased with increasing over Bi content of 10% excess. The BLT film with Bi content of 10% excess was measured to have a dielectric constant of 326 and dielectric loss of 0.024. The BLT thin films showed little polarization fatigue test up to 3.5$\times$10$^{9}$ bipolar switching cycling.

RF 마그네트론 스퍼터링법에 의한 SBT 박막의 강유전체 특성 (Ferroelectric Properties of SBT Thin Films Deposited by RF Magnetron Sputering Method)

  • 조춘남;김진사;최운식;박용필;김충혁
    • 한국전기전자재료학회논문지
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    • 제14권9호
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    • pp.731-735
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    • 2001
  • S $r_{0.89}$B $i_{2.4}$T $a_2$ $O_{9}$ (SBT) thin films are deposited on Pt-coated electrode(Pt/Ti $O_2$/ $SiO_2$/Si) using RF magnetron sputtering method. In the XRD pattern, the SBT thin films had (105) orientation. As annealing temperature was increased from $600^{\circ}C$ to 85$0^{\circ}C$, the intensities of peak were increased. In the SEM images, Bi-layered perovskite phase was crystallized above $650^{\circ}C$ and rod-like grains grew above 75$0^{\circ}C$. The maximum remanent polarization and the coercive electric field at annealing temperature of 75$0^{\circ}C$ are 11.60$\mu$C/$\textrm{cm}^2$ and 48kV/cm respectively. The dielectric constant and leakage current density at annealing temperature of 75$0^{\circ}C$ are 213 and 1.01x10$^{-8}$ A/$\textrm{cm}^2$, respectively. The fatigue characteristics of SBT thin filmsdid not change up to 10$^{10}$ switching cycles.s.s.

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다양한 열처리 분위기에 따른 SBT 커패시터의 전기적 특성 (Electrical Properties of SBT Capacitors with various Annealing Atmosphere)

  • 조춘남;김진사;신철기;최운식;김충혁;홍진웅;이준웅
    • 한국전기전자재료학회논문지
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    • 제16권3호
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    • pp.207-213
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    • 2003
  • The Sr$\_$0.7/Bi$\_$2.6/Ta$_2$O$\_$9/(SBT) thin films are deposited on Pt-coated electrode(Pt/TiO$_2$/SiO$_2$/Si) using RF magnetron sputtering method. The structural and electrical properties of SBT capacitors were influenced with annealing atmosphere. In the XRD pattern, the SBT thin films in all annealed atmosphere had (105) orientation. In the SEM images, Bi-layered perovskite phase was crystallized in all annealing atmosphere and grain largely grew in oxygen annealing atmosphere. The maximum remnant polarization and the coercive electric field in oxygen annealing atmosphere are 12.40[${\mu}$C/cm$^2$] and 30[kV/cm] respectively. The dielectric constant and leakage current density of capacitors annealed oxygen atmosphere are 340 and 2.13${\times}$10$\^$-9/ [A/cm$^2$] respectively. The fatigue characteristics of SBT capacitors did not change up to 10$\^$10/ switching cycles.