• Title/Summary/Keyword: Material Decomposition

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Effects of Bottom Electrode to Dielectric and Electrical Properties of MOD Derived Ferroelectric SBT Thin Films (MOD 법으로 제조한 강유전성 SBT 박막에서 하부전극이 유전 및 전기적 특성에 미치는 영향)

  • 김태훈;송석표;김병호
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.13 no.8
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    • pp.694-699
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    • 2000
  • S $r_{0.9}$/B $i_{2.1}$/T $a_{2}$/ $O_{9}$ solutions was synthesized by MOD (metalorganic decomposition) method. SBT thin films with 2000$\AA$ thickness were prepared on Ir $O_2$/ $SiO_2$/Si and Pt/Ti/ $SiO_2$/Si substrates using the spin coating process and then investigated the dielectric and electrical properties of them. In the case of using Ir $O_2$bottom electrode the hysteresis loop was saturated at lower temperature than Pt/Ti electrode but the breakdown phenomenon was occurred at low voltage because of the rough surface morphology and porous microstructure of SBT thin films. As the results of the fatigue and imprint characteristics related to the lifetime and reliability of devices after 10$^{10}$ cycles the fatigue rates were about 10% at the Ir $O_2$and Pt/Ti bottom electrodes. Both SBT thin films with Ir $O_2$ and with Pt/Ti bottom electrodes show a slight tendency to imprint after 10$^{9}$ cycles but do not lead to a failure.e.e.

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Characteristics of MFIS using Pt/BLT/$CeO_2$/Si structures (Pt/BLT/$CeO_2$/Si 구조를 이용한 MFIS의 특성)

  • Lee, Jung-Mi;Kim, Chang-Il;Kim, Kyoung-Tae;Kim, Dong-Pyo;Hwang, Jin-Ho;Lee, Cheol-In
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.11a
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    • pp.186-189
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    • 2002
  • The MFIS capacitors were fabricated using a metalorganic decomposition method. Thin layers of $CeO_2$ were deposited as a buffer layer on Si substrate and BLT thin films were used as a ferroelectric layer. The electrical and structural properties of the MFIS structure were investigated. X-ray diffraction was used to determine the phase of the BLT thin films and the quality of the $CeO_2$ layer. The morphology of films and the interface structures of the BLT and the $CeO_2$ layers were investigated by scanning electron microscopy. The width of the memory window in the C-V curves for the MFIS structure is 4.78 V. The experimental results show that the BLT-based MFIS structure is suitable for non-volatile memory FETs with large memory window.

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Properties of SiOCH Thin Film Bonding Mode by BTMSM/O2 Flow Rates (BTMSM/O2 유량변화에 따른 SiOCH 박막 결합모드의 2차원 상관관계 특성)

  • Kim, Jong-Wook;Hwang, Chang-Su;Kim, Hong-Bae
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.21 no.4
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    • pp.354-361
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    • 2008
  • The dielectric characteristics of low-k interlayer dielectric materials was fabricated by plasma enhanced chemical vapor deposition (PECVD). BTMSM precursor was evaporated and introduced with the flow rates from 16 sccm to 25 sccm by 1sccm step in the constant flow rate of 60 sccm $O_2$ in process chamber. Manufactured samples are analyzed components by measuring FT/IR absorption lines. Decomposition each Microscopic structures through two-dimensional correlation analysis about mechanisms for the formation of SiOCH in $SiOCH_3$, Si-O-Si and Si-$CH_3$ bonding group and analyzed correlation between the micro-structure of each group. It is a tendency that seems to be growing of Si-O-Ci(C) bonding group and narrowing of Si-O-$CH_3$ bonding group relative to the increasing flow-rate BTMSM. The order of changing sensitivity about changes of flow-rate in Si-O-Si(C) bonding group is cross link mode$(1050cm^{-1})$ $\rightarrow$ open link mode$(1100cm^{-1})\rightarrow$ cage link mode $(1140cm^{-1})$.

Potentiometric NOx sensors for automotive exhaust using YSZ(yittria stabilized zirconia) electrolyte (YSZ 전해질을 이용한 농담전지식 자동차용 NOx센서)

  • Park, Jin-Su;Park, Kwang-Chol;Park, C.O.
    • Journal of Sensor Science and Technology
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    • v.16 no.6
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    • pp.434-440
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    • 2007
  • Two kinds of new NOx sensing mechanism was proposed and examined. One of those was potentiomtric sensor based on the measurement of decomposed oxygen from NO using YSZ porous diffusion barrier and Pd catalytic electrode. The sensor based on decomposed oxygen measurement responded to the range of 300 - 1000 ppm NO in $N_{2}$ environment and the sensitivities were coincident with theoretical values at 700 and $800^{\circ}C$ but the decomposition rate depended on gas flow rate. The other sensor was equilibrium potentiometric type using $Gd_{2}O_{3}$-nitrates solid solution as sensing material. The sensor using $Gd_{2}O_{3}$-nitrates solid solution was suitable for NOxxsensing at $700^{\circ}C$ in 5 % oxygen and the sensitivity was 19.3 mV/decade. However, long term stability of the sensing material at high temperature was not sufficient.

Effect of ZrO2 Buffer Layers for Pt/Bi3.25La0.75Ti3O12/ZrO2/Si (MFIS)-FET Structures (Pt/Bi3.25La0.75Ti3O12/ZrO2/Si (MFIS)-FET 구조를 위한 ZrO2 Buffer Layer의 영향)

  • Kim, Kyoung-Tae;Kim, Chang-Il
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.18 no.5
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    • pp.439-444
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    • 2005
  • We investigated the structural and electrical properties of BLT films grown on Si covered with $ZrO_{2}$ buffer layer. The BLT thin film and $ZrO_{2}$ buffer layer were fabricated using a metalorganic decomposition method. The electrical properties of the MFIS structure were investigated by varying thickness of the $ZrO_{2}$ layer. AES and TEM show no interdiffusion and reaction that suppressed using the $ZrO_{2}$ film as a buffer layer The width of the memory window in the C-V curves for the MFIS structure decreased with increasing thickness of the $ZrO_{2}$ layer. It is considered that the memory window width of MFIS is not affected by remanent polarization. Leakage current density decreased by about four orders of magnitude after using $ZrO_{2}$ buffer layer. The results show that the $ZrO_{2}$ buffer layers are prospective candidates for applications in MFIS-FET memory devices.

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

  • 김경태;김창일;강동희;심일운
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.15 no.9
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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.

Ferroelectric Properties of Bi3.25La0.75Ti3O12 Thin Films with Various Drying Temperature for FRAM Applications (FRAM 응용을 위한 건조온도에 따른 BLT 박막의 강유전 특성)

  • 김경태;김동표;김창일;김태형;강동희;심일운
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.4
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    • pp.265-271
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    • 2003
  • Ferroelectric lanthanum-substituted Bi$_4$Ti$_3$O$_{12}$(BLT) thin films were fabricated by spin-coating onto a Pt/Ti/SiO$_2$/Si substrate by metalorganic decomposition technique. The grain size in BLT thin films were prepared with controlled by various drying process. The effect of grain size on the crystallization and ferroelectric properties were investigated by x-ray diffraction and field emission scanning electron microscope. The dependence of crystallization and electrical properties are related to the grain size in BLT thin films with different drying temperature. The remanent polarization of BLT thin film increases with the increasing grain size. The value of 2P$_{r}$ and E$_{c}$ of BLT thin film dried at 45$0^{\circ}C$ were 25.9 $\mu$C/$\textrm{cm}^2$ and 85 kV/cm, respectively. The BLT thin film with larger grain size has better fatigue properties. The fatigue properties revealed that small grained film showed more degradation of switching charge than large grained films.lms.s.

Synthesis and Characterization of Mn3O4-Graphene Nanocomposite thin Film by an ex situ Approach

  • Kang, Myunggoo;Kim, Jung Hun;Yang, Woochul;Jung, Hyun
    • Bulletin of the Korean Chemical Society
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    • v.35 no.4
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    • pp.1067-1072
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    • 2014
  • In this study, we report a new approach for $Mn_3O_4$-graphene nanocomposite by ex situ method. This nanocomposite shows two-dimensional aggregation of nanoparticle, and doping effect by decorated manganese oxide ($Mn_3O_4$), as well. The graphene film was made through micromechanical cleavage of graphite on the $SiO_2/Si$ wafer. Manganese oxide ($Mn_3O_4$) nanoparticle with uniform cubic shape and size (about $5.47{\pm}0.61$ nm sized) was synthesized through the thermal decomposition of manganese(II) acetate, in the presence of oleic acid and oleylamine. The nanocomposite was obtained by self-assembly of nanoparticles on graphene film, using hydrophobic interaction. After heat treatment, the decorated nanoparticles have island structure, with one-layer thickness by two-dimensional aggregations of particles, to minimize the surface potential of each particle. The doping effect of $Mn_3O_4$ nanoparticle was investigated with Raman spectra. Given the upshift in positions of G and 2D in raman peaks, we suggest that $Mn_3O_4$ nanoparticles induce p-doping of graphene film.

Comparative Study on the Degumming Methods of Hemp Fiber (대마섬유의 정련 방법에 관한 비교 연구)

  • Lim, Hyeong-Gyu;Kim, Hee-Sook
    • Fashion & Textile Research Journal
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    • v.22 no.4
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    • pp.523-533
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    • 2020
  • Previous studies are used to examine cellulose content, degumming period, fiber quality, production yield, production cost, development limit of fiber according to physical, chemical, and microbial degumming methods. Three types of degumming methods are used to measure surface condition after degumming, necessity of additional degumming and degree of impurity removal. First, previous studies confirmed that the microbial degumming method is superior in terms of cellulose content, fiber quality, production yield, production cost, and fiber development possibility. Second, surface condition and the necessity of additional degumming were analyzed by SEM. The black skin binding material was removed in the case of the Sangnangyi and chemical degumming; however, it was insufficient and further degumming was required. Skin fiber binding material was removed in the case of microbial degumming and the surface was cleanest after degumming; in addition, most showed the form of yarn decomposition. The FT-IR spectrum determined the degree of removal of impurities and showed that it can utilize inherent physical properties as the best degumming method. The degree of removal of pectin and lignin by microbial degumming was cleanest with hemicellulose also reduced by microbial degumming.

Thermal Shock Resistance of $Al_2$TiO$_5$ Ceramics Prepared from Electrofused Powders (전기용융 분말로부터 합성된 $Al_2$TiO$_5$ Ceramics의 열충격 저항성)

  • ;Constantin Zografou
    • Journal of the Korean Ceramic Society
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    • v.35 no.10
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    • pp.1061-1069
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    • 1998
  • The thermal instability of Al2TiO5 Ceramics was contrlled by solid solution with MgO SiO2 and ZrO2 through electrofusion in an arc furnace. The thermal expansion properties of Al2TiO5 composites show the hysteresis due to the strong anisotropy of The crystal axes of these material. These phenomena are ex-plained by the opening and closing of microcracks. The difference in microcracking temperatures e.g 587.6(ATG2), 405.9(ATG3) and 519.7$^{\circ}C$(ATG4) is caused by the difference in grain size and stabilizer type. The thermal shock behaviour under cyclic conditions between 750-1400-75$0^{\circ}C$ show no change in mi-crostructure and phase assemblage for all three stabilized specimens. After the thermal loading test at 110$0^{\circ}C$ for 100hrs. ATG1 and ATG2 materials decomposes completely to its components corundum and ru-tile in both cases. However with approximatelly 20% retention of the Al2TiO5 Thus in order to prevent decomposition of the stabilized material in the critical temperature range 800-130$0^{\circ}C$ it must be traversed within a short period of time.

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