• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2004년도 추계학술대회 논문집 전기물성,응용부문
• /
• pp.75-78
• /
• 2004

$Bi_{3.25}Eu_{0.75}Ti_3O_{12}$ (BET) thin films were deposited on the $LaNiO_3$ (LNO (100))/Si and Pt/Ti/$SiO_2$/Si substrates by the metal-organic decomposition method. Structural and dielectric properties of BLT thin films for the applications in nonvolatile ferroelectric random access memories were investigated. Both the structure and morphology of the films were analyzed by x-ray diffraction (XRD) and atomic force microscope (AFM). Even at low temperatures $650^{\circ}C$, the BET thinfilms were successfully deposited on LNO bottom electrode and exhibited (001) and (117) orientation. Compared with the Pt electrode films, the BET thin films on the LNO electrode annealed at $650^{\circ}C$ showed better dielectric constantsand remanent polarization. The BET thin films on the LNO electrode for the annealing temperature of $650^{\circ}C$, the remanent polarization Pr and coercive field were $45.6\;C/cm^2$ and 171 kV/cm, respectively.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
• /
• pp.264-267
• /
• 2004

[ $Bi_{3.25}La_{0.75}Ti_3O_{12}$ ] (BLT) thin films were prepared by using metal organic decomposition method onto the $LaNiO_3$ (LNO) bottom electrode. Both the structure and morphology of the films were analyzed by x-ray diffraction (XRD) and atomic force microscope (AFM). Even at low temperatures ranging from 450 to $650^{\circ}C$, the BLT thinfilms were successfully deposited on LNO bottom electrode and exhibited (117) orientation. The BLT thin films annealed as low as $600^{\circ}C$ showed excellent ferroelectricity, higher remanent polarization and no significant degradation of switching charge at least up to $5{\times}10^9$ switching cycles at a frequency of 100 kHz and 5 V. For the annealing temperature of $600^{\circ}C$, the remanent polarization Pr and coercive field were $23.5\;C/cm^2$ and 120 kV/cm, respectively.

• 한국재료학회지
• /
• 제6권12호
• /
• pp.1263-1269
• /
• 1996

반도체 메모리 소자에 이용되는 하부전극의 Pt 박막을 MOCVD 증착방법을 이용하여 SiO2(100nm)/Si 기판위에 증착하였다. 반응개스로 O2개스를 사용하였을 경우에 순수한 Pt 박막을 얻었으며 증착층은(11)우선방향을 가지고 성장하였다. 증착온도가 45$0^{\circ}C$에서는 결정립 경계에 많은 hole이 형성되어 박막의 비저항을 증가시켰다. MOCVD에 의해 얻어진 Pt 박막은 전 증착온도범위에서 인장응력을 가지고 있었으며 40$0^{\circ}C$이상의 온도에서 hole이 형성되면서 응력은 감소하였다. MOCVD-Pt 위에 PEMOCVD로 증착한 강 유전체 SrBi2Ta2O9박막은 균일하고 치밀한 미세구조를 보였다.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
• /
• pp.399-402
• /
• 2005

We have studied the Pixel Isolated Phase Separated Composite Organic Film (PI-PSCOF). The PI-PSCOF can be made by the anisotropic phase separation between Ferroelectric Liquid Crystals and Pre-polymer materials by irradiating the UV with optimizing its intensity and time. In the technology, the FLC molecules are isolated in pixels where FLCs are surrounded by the inter-pixel vertical polymer walls and the horizontal polymer films on the upper substrate. The good merits of this technology are fast response time, and good mechanical and thermal stability against external high pressure and temperature. We will compare the results obtained from FLC, PSCOF, and PI-PSCOF modes by using the electro-optic measurement and x-ray scattering, and mechanical method. We believe that the PI-PSCOF technology can be a best candidate for future Flexible Display Applications.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
• /
• pp.1394-1395
• /
• 2006

$(Na_{0.5}LaK_{0.5})NbO_3$ (NKN) thin films were fabricated by the alkoxide-based MOD method. NKN stock solutions were made spin-coated onto the Pt/Ti/$SiO_2$/Si substrate. The structural properties of the NKN thin films examined by x-ray diffraction. The perovskite phase was obtained as a function of the annealing temperature from $550^{\circ}C$ to $700^{\circ}C$ for 1h. The crystallinity and grain size of the NKN thin films increased with increasing annealing temperature. The dielectric constants and loss of the NKN thin films annealed at $650^{\circ}C$ ($t_{eq}$=2.35 nm) showed 323 and 0.025.

• Bulletin of the Korean Chemical Society
• /
• 제17권11호
• /
• pp.1023-1031
• /
• 1996

A new synthetic route for the lanthanum β-diketonate compounds via in-situ formed lanthanum alkyl complexes was developed in the process for the development of suitable MOCVD (metal-organic chemical vapor deposition) precursors of PLT, one of the promising material for the ferroelectric film. A series of lanthanum β-diketonate compounds were successfully synthesized by this method. This new method is found to have some merits; versatile method for almost every β-diketone, β-hydroxyketone, and β-hydroxyaldehyde, short reaction time, easy purification for high purity, moderate to high yield, and easy access to anhydrous compounds. In some cases, anhydrous oligomeric products fail to show the higher volatility. On the other hand, some lanthanum β-diketonates with aromatic groups such as La(1,3-biphenyl-l,3-propandione)3 are found to have favorable properties for a precursor of lanthanum oxide, one of major components of PLT, such as low melting point, and much higher decomposition temperature. A plausible pyrolysis mechanism is proposed by the TGA, where consecutive dissociation of R, CO, CH, C, and O fragments occurs.

• Journal of Electrical Engineering and Technology
• /
• 제4권4호
• /
• pp.527-530
• /
• 2009

$(Ba_{0.57}Sr_{0.33}Ca_{0.10})TiO_3$(=BSCT) powders, prepared by the sol-gel method, were doped using $MnCO_3$ as the acceptor and $Dy_2O_3$ as the donor. This powder was mixed with an organic vehicle. BSCT thick films were fabricated by the screen-printing techniques on the alumina substrate. The structural and dielectric properties of BSCT thick films were investigated with variation of the $Dy_2O_3$ amount. As a result of the differential thermal analysis (DTA), the exothermic peak was observed at around $670^{\circ}C$ due to the formation of the polycrystalline perovskite phase. All the BSCT thick films showed the XRD patterns of a typical polycrystalline perovskite structure. The average grain size of BSCT thick films decreased with an increasing amount of $Dy_2O_3$. The relative dielectric constant and dielectric loss of the BSCT thick film doped $Dy_2O_3$ 0.1mol% were 4637.4 and 1.6% at 1kHz, respectively.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1996년도 하계학술대회 논문집 C
• /
• pp.1505-1507
• /
• 1996

In this study, $(Pb_{0.88}La_{0.12})(Zr_{0.40}Ti_{0.60})O_{2.97}$ (La/Zr/Ti=12/40/60) ceramic thin films were fabricated from an alkoxide-based by Sol-Gel method. PLZT stock solutions were made and spin-coated on the ITO-glass rubstrate at 4000[rpm] for 30[sec]. Coated specimens were baked to remove the organic materials at $400[^{\circ}C]$ for 10[min]. This procedure was repeated 5 times. The coated films were finally annealed at $450{\sim}700[^{\circ}C]$ for 1[hr]. The ferroelectric perovskite phases precipitated under the sintering of $550{\sim}700[^{\circ}C]$ for 1[hr]. Relative dielectric constant of the PLZT thin were increased with increasing the sintering temperature, the thin file sintered at $650[^{\circ}C]$ showed the highest value of 196. But in the PLZT thin film sintered at $700[^{\circ}C]$, relative dielectric constant was greatly decreased due to reacts between ITO electrode and glass substrate. In all thin films, the transmittance was more than 70[%] (at 632.8[nm]).

• 한국세라믹학회지
• /
• 제42권4호
• /
• pp.219-223
• /
• 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.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1997년도 하계학술대회 논문집 C
• /
• pp.1330-1332
• /
• 1997

In this paper, PNN-PZN-PZT ceramics were fabricated with various mole ratio of the PZT[$Pb(Zr_{1/2}Tid_{1/2})O_3$]. PNN [$Pb(Ni_{1/3}Nb_{2/3})O_3$] and PZN[$Pb(Ni_{1/3}Nb_{2/3})O_3$ powders prepared by double calcination and PZT powders prepared by molten-salt synthesis method. The formation rate of perovskite phase in PNN-PZN-PZT ceramics could be obtained about 92% at PZT 0.3 mole ratio. The relative permittivity of specimen with PZT 0.3 mole ratio was shown 5,320 and appeared the relaxor ferroelectric feature. The maximum piezoelectric coefficient $d_{31}$ to be used for evaluation the displacement of piezoceramics in PNN-PZN-PZT ceramics was $324{\times}10^{-12}$(C/V) at the vicinity of morphotropic phase boundary and was larger than that of solid PZT ceramics($120{\times}10^{-12}C/V$).