• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.9
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• pp.810-814
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• 2005

[ $Pb(Zr_{0.2}Ti_{0.8})O_3/SrRuO_3$ ] heteroepitaxial thin films were deposited at various temperatures on single crystal $SrTiO_3$ substrates by pulsed laser deposition and characterized for the microstructural and ferroelectric properties. The $SrTiO_3$ substartes etched by buffered oxide etch $(pH{\thickapprox}5.8)$ solution for 20s followed by the thermal annealing at $1000^{\circ}C$ for 1h showed the terrace ledges with a 0.4nm height. The $SrRuO_3$ bottom electrodes with a thickness of 52nm grown on $SrTiO_3$ single crystal also exhibit a terrace ledge similar to that of $SrTiO_3$. The PZT thin films were grown with an epitaxial relationship and showed typical P-E hysteresis loops shown at the epitaxial films. The 56nm thick-PZT films deposited at $650^{\circ}C$ exhibit a remanent polarization $(p_r)$ of $80{\mu}C/cm^2$ and a coercive field $(E_c)$ of 160kV/cm.

• Journal of Sensor Science and Technology
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• v.11 no.1
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• pp.48-53
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• 2002

Ferroelectric $Pb_{0.99}[(Zr_{0.6}Sn_{0.4})_{1-x}Ti_x]_{0.98}Nb_{0.02}O_3$(PNZST) thin films were deposited by a RF magnetron sputtering on $(La_{0.5}Sr_{0.5})CoO_3$(LSCO)/Pt/Ti/$SiO_2$/Si substrate using a PNZST target with excess PbO of 10 mole%. The crystallinity and electrical properties of the thin films with various composition ratio were investigated. The thin films deposited at the substrate temperature of $500^{\circ}C$ and the power of 80 W were crystallized to a perovskite phase after rapid thermal annealing(RTA) at $650^{\circ}C$ for 10 seconds in air. A PNZST thin films with Ti of 10 mole% showed the good crystallinity and ferroelectric properties. The remanent polarization and coercive field of the PNZST capacitor were about $20\;{\mu}C/cm^2$ and 50 kV/cm, respectively. The reduction of the polarization after $2.2{\times}10^9$ switching cycles was less than 10%.

• Journal of the Korean Vacuum Society
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• v.19 no.1
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• pp.52-57
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• 2010

$BiFeO_3/Pb(Zr_{0.52}Ti_{0.48})O_3$(BFO/PZT) multilayer thin films have been prepared on a Pt/Ti/$SiO_2$/Si(100) substrate by chemical solution deposition. BFO single layer, BFO/PZT bilayer and multilayer thin films were studied for comparison. X-ray diffraction analysis showed that the crystal structure of all films was multi-orientated perovskite phase without amorphous and impurity phase. The leakage current density at 500 kV/cm was reduced by approximately four and five orders of magnitude by bilayer and multilayer structure films, compared with BFO single layer film. The low leakage current density leads to saturated P-E hysteresis loops of bilayer and multilayer films. In BFO/PZT multlayer film, saturated remanent polarization of $44.3{\mu}C/cm^2$ was obtained at room temperature at 1 kHz with the coercive field($2E_c$) of 681.4 kV/cm.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.2
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• pp.105-108
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• 2005

The Pb(Zr,Ti)O$_3$ thin films were fabricated with Pb(La,Ti)O$_3$ buffers in-situ onto Pt/Ti/SiO$_2$/Si substrates by pulsed laser deposition method. We have observed the increase of the remanent polarization using PLT buffers. The remanent polarization value of 33.4 $\mu$C/$\textrm{cm}^2$ and the coercive field value of 66.4 kV/cm were obtained when the PLT tufter was deposited for 15 seconds. Enhancement of the polarization is resulted from the enhanced orientation of PZT thin film because of the PLT buffet layer.

• Journal of Korean Ophthalmic Optics Society
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• v.3 no.1
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• pp.15-19
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• 1998

The purpose of this study, when one prepared lead zirconate thin films by sol-gel method, was to find the preferred direction of crystal growth and dielectric characteristics for ratio of Pb and Zr. We used the Pt/Ti/$SiO_2$/Si substrate, and annealing condition was $800^{\circ}C$ for lminute. When Pb was deficient, preferred direction was <221>. And when it was stoichiometric ratio, they were grown <200> and <221> direction. But they have antiferroelectric properties, they don't appear distinct domain switching.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1618-1620
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• 2004

The $Pb(Zr_{0.4}Ti_{0.6})O_3/Pb(Zr_{0.6}Ti_{0.4})O_3$ [PZT(4060)/(6040)] multilayered thin films were deposited by RF Sputtering method on the Pt/Ti/$SiO_2$/Si substrate. This procedure was repeated several times to form PZT(4060)/(6040) heterolayerd thin films. The effects on the structural and dielectric properties of PZT multilayered thin films were investigated. The MFM(Metal Ferroelectric Metal) type capacitors were made using the PZT(4060)/(6040) multilayered thin films deposited with optimum deposition condition. An enhanced dielectric property was observed in the PZT(4060)/(6040) multilayered thin films. The relative dielectric constant and dielectric loss at 100Hz of the PZT(4060)/(6040)-5 multilayered thin films were about 1106 and 0.016, respectively.

• Proceedings of the Korean Vacuum Society Conference
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• 1995.06a
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• pp.41-41
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• 1995

• Korean Journal of Materials Research
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• v.10 no.5
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• pp.360-363
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• 2000

Deformation in the hysteresis loop of $Pb(Zr,Ti)O_3$ (PZT) thin films with various Zr/Ti ratios has been studied by varying the top electrode preparation method and the annealing temperature. Pt/PZT/Pt capacitors was found to be positively poled due to dc plasma potential generated during reactive ion etch (RIE) of Rt. Internal field is formed by space charges trapped at domain boundaries. Aging phenomenon such as constriction in the middle of the hysteresis loop was observed in the PZT film with top electrode deposited by sputtering. Top electrode annealing restores the hysteresis loop by removing the space charges. As Zr/Ti ratio decrease, voltage shift increases and an-nealing temperature at which internal field disappears also increases.

• Proceedings of the IEEK Conference
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• 2000.06b
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• pp.24-27
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• 2000

Ferroelectric P $b_{0.99}$〔(Z $r_{0.6}$S $n_{0.4}$)$_{0.9}$ $Ti_{0.1}$〕$_{0.98}$N $b_{0.02}$ $O_3$(PNZST) thin films were deposited by a RF magnetron sputtering on (L $a_{0.5}$S $r_{0.5}$)Co $O_3$(LSCO)/Pt/Ti/ $SiO_2$/Si substrate using a PNZST target with excess PbO of 10 mole％. The thin films deposited at the substrate temperature of 500 $^{\circ}C$ were crystallized to a perovskite phase after rapid thermal annealing(RTA) The thin films annealed at 650 $^{\circ}C$ for 10 seconds in air exhibited the good crystal structures and ferroelectric properties. The remanent polarization and coercive field of the PNZST capacitor were about 20 $\mu$C/$\textrm{cm}^2$ and 50 kV/cm, respectively. The reduction of the polarization after 2.2$\times$10$^{9}$ switching cycles was less than 10 ％.0 ％.％.0 ％.0 ％.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.199-202
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• 1999

반강유전 물질인 Pb[(Zr. Sn)Ti]NbO₃를 La/sub 0.5/Sr/sub 0.5/CoO₃/Pt/Ti/SiO₂/Si 기판상에 RF 마그네트론 스퍼터링 방법으로 박막화하여 그 결정성과 전기적 특성을 조사하였다. 80 W의 RF power, 400℃의 기판온도, Ar:O₂= 9:0.5의 분위기에서 증착되고, 650 ℃에서 10초동안 RTP(Rapid Thermal Process) 방법으로 열처리된 박막이 가장 우수한 페로브스카이트 구조를 보였으며, 10 ㎑ 에서 유전상수(ε')는 721, 유전손실(tan δ)은 0.06을 나타내었다. 잔류분극(Pr)은 15.5 μC/㎠ 였으며, 항전계(Ec)는 51 ㎸/㎝로 비교적 낮은 값을 나타내었다.