• 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]

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전기물성,응용부문
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• pp.71-73
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• 2005

Ferroelectric PZT heterolayered thick films were fabricated by the alkoxide-based sol-gel method. PZT(20/80) and PZT(80/20) paste were made and alternately screen-printed on the alumina substrates. The coating and drying procedure was repeated 4 times to form the heterolayered thick films. The thickness of the PZT heterolayered thick films was approximately 60 mm. All PZT thick films showed the typical XRD patterns of a perovskite polycrystalline structure. The relative dielectric constant and the dielectric loss of the PZT thick films sintered at $1050^{\circ}C$ were 1382 and 1.90%, respectively. The remanent polarization and coercive field of the PZT thick films sintered at $1050^{\circ}C$ were $14.15{\mu}C/cm^2$ and 19.13kV/cm, respectively.

• 한국전기전자재료학회논문지
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• 제14권5호
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• pp.356-361
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• 2001

The structureal, dielectric and piezoelectric properties of Pb[(Sb$\_$1/2/Nb$\_$1/2/)$\_$x/-(Ni$\_$1/3/Nb$\_$2/3/)$\_$0.15-x/-(Zr$\_$y/Ti$\_$1-y/)$\_$0.85/]O$_3$(x=0∼0.05, y=0.47∼0.52) ceramics were investigated with the substitution of Pb(Sb$\_$1/2/Nb$\_$1/2/)O$_3$(abbreviated PSN) and the Zr/Ti ratio. At Zr/Ti ratio of 50/50, tetragonality was decreased and grain size abruptly decreased with the increase of PSN substitution. Curie temperature was decreased and dielectric constant increased with the substitution of PSN. The coercive field increased and remnant polarization decreased with the substitution of PSN. Electromechanical coupling factor(k$\_$p/) showed the highest value of 0.622 at 1mol% PSN, but mechanical quality factor(Q$\_$m/) showed the minimum value at that composition. Dielectric constant and electromechanical coupling factor with the Zr/Ti ratio showed maximum values at Zr/Ti ratio of 50/50 and mechanical quality factor showed minimum values near the Zr/Ti ratio of 50/50.

• E2M - 전기 전자와 첨단 소재
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• 제10권10호
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• pp.983-988
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• 1997

We investigated the structural and dielectric properties of PZT(20/80)/PZT(80/20) heterolayered thin films that fabricated by the alkoxide-based Sol-Gel method. PZT(20/80)/PZT(80/20) heterolayered thin films were spin-coated on the Pt/Ti/SiO$_2$/Si substrate with PZT(20/80) film of tetragonal structure and PZT(80/20) film of rhombohedral structure by turns. Each layers were dried to remove the organic materials at 30$0^{\circ}C$ for 30min and sintered at $650^{\circ}C$ for 1hr. This procedure was repeated several times to form PZT(20/80)/PZT(80/20) heterolayered films and thickness of the film obtained by one-times of drying/sintering process was approximately 80-90nm. PZt-1, 3, 5 films with top layer of PZT(20/80) film of tetragonal structure showed fine grain structure and PZT-2, 4, 6 films with top layer of PZT(80/20) film of rhombohedral structure showed the dense grain microstructure without rosette-type. Dielectric constant and dielectric loss of the PZT-6 film were approximaterly 1385 and 3.3% respectively. Increasing the number of coatings remanent polarization was increased and coercive field was decreased and the values of the PZT-6 film were 8.13$\mu$C/cm$^2$and 12.5kV/cm respectively.

• 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.

• Transactions on Electrical and Electronic Materials
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• 제7권6호
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• pp.279-282
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• 2006

[ $Pb(Zr_{0.4}Ti_{0.6}O_{3}\;and\;Pb(Zr_{0.6}Ti_{0.4})O_{3}$ ] paste were made and alternately screen-printed on the $Al_{2}O_{3}$ substrates. We have introduced a press-treatment to obtain a good densification of screen printed films. The porosity of the thick films was decreased with increasing the applied pressure and the thick films pressed at 60 MPa showed the dense microstructure and thickness of about $76\;{\mu}m$. The remanent polarization and coercive field increased with increasing applied pressure and the values for the PZT thick films pressed at 60 MPa were $17.04{\mu}C/cm^{2}$ and 78.09 kV/cm, respectively.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.255-258
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• 2000

In this study, the structural, dielectric and piezoelectric properties of Pb[(Sb$\sub$1/2/Nb$\sub$1/2/)$\sub$x/- (Ni$\sub$1/3/Nb$\sub$2/3/)$\sub$0.15-x/- (Zr,Ti)$\sub$0.85/]O$_3$(x = 0, 0.01, 0.02, 0.03, 0.04, 0.05) ceramics is investigated as a function of Pb(Sb$\sub$1/2/Nb$\sub$1/2/)O$_3$ (abbreviated PSN) substitution. With the increase of PSN substitution, the crystal structure is transO$_3$formed from the tetragonal phase to the rhombohedral phase and the grain size is decreased abruptly. The curie temperature is decreased with the PSN substitution. The dielectric constant is increased with the PSN substitution and maximum value of 2290 is obtained at 4mol% PSN. With the PSN substitution, the coercive field is increased and the remnant polarization is decreased. The Electromechanical coupling factor(k$\sub$p/) Is showed the highest value of 0.622 at lmol% PSN and the mechanical quality factor(Q$\sub$m/) is decreased abruptly with the PSN substitution.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권12호
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• pp.553-558
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• 2003

The A S $r_{0.7}$B $i_{2.6}$T $a_2$ $O_{9}$ (SBT)thin films are deposited on Pt-coated electrode(Pt/$TiO_2$/$SiO_2$/Si) using a RF magnetron sputtering method. The electrical properties of SBT capacitors with top electrodes were studied. In the XRD pattern, the SBT thin films in all annealing temperatures had (105) orientation. In the SEM images, Bi-layered perovskite phase was crystallized at 75$0^{\circ}C$ and grains largely grew in oxygen annealing atmosphere. The electrical properties of SBT capacitor with top electrodes represent a favorable properties in Pt electrode. The maximum remanent polarization and the coercive electric field with Pt electrode are 12.40C/$\textrm{cm}^2$ and 30kV/cm, respectively. The dielectric constant and leakage current density with Pt electrode is 340 and 6.8110$^{-10}$ A/$\textrm{cm}^2$, respectively.y.y.

• 한국전기전자재료학회논문지
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• 제13권2호
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• pp.143-150
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• 2000

Ferroelectric SrxBi2+yTa2O9+$\alpha$ thin films with various compositions(x=0.7, 0.8, 1, y=0.3, 0.4) were prepared by sol-gel method. The film with moled ratio of 0.8:2.3:2.0 in Sr/Bi/Ta, which was deposited on Pt/SiO2/Si (100), showed better ferroelectric properties than other films. To investigate substrate effects, the same compositions were spin coated on Pt/Ti/SiO2/Si (100) substrates. At an applied voltage of 5V, the dielectric constant($\varepsilon$r), remanent polarization (2Pr) and coercive field (Ec) of the Sr0.8Bi2.3Ta2O9+$\alpha$ thin film prepared on Pt/Ti/SiO2/Si (100) were about 296, 24$\mu$C/$\textrm{cm}^2$ and Ec of 49kV/cm respectively. Both SBT films firred at 80$0^{\circ}C$ revealed no fatigue up to 1010 cycles. Retention characteristics of these capacitors showed no degradation up to 104 sec.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 센서 박막재료 반도체 세라믹
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• pp.190-193
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• 2003

Sm-doped lead zirconate titanate($Pb_{1.1}(Zr_{0.6}Ti_{0.4})O_3$; PZT) thin films on the Pt(111)/Ti/$SiO_2$/Si(100) substrates prepared by a sol-gel method. The effect on structural and electrical properties of PZT thin films measured according to the Sm content. Sm-doping altered significantly dielectric and ferroelectric properties. The remanent polarization and the coercive field decreased with the increasing Sm content. The dielectric constant and the dielectric loss of PZT thin films decreased with the increasing Sm content. At 100 kHz, the dielectric constant and the dielectric loss of. the 0.3 mol% of Sm-doped PZT thin film were 1200 and 0.12 respectively. The remanent polarization (2Pr) of the 0.3 mol% of Sm-doped PZT thin film was $52.13{\mu}C/cm^2$ and the coercive field was 94.01 kV/cm. The 0.3 mol% of Sm-doped PZT thin film showed an improved fatigue characteristic comparing to the undoped PZT thin film.