• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.269-272
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• 1999

In this study, electrical properties and TCFr of Pb(Sb$_{1}$2/Nb$_{1}$2/)O$_3$-Pb(Mn $_{1}$3/Nb$_{2}$3/)O$_3$-Pb(zr, Ti)O$_3$ composition ceramics were investigated wish the Zr/Ti ratio and the additions of Y2O3. and Fe$_2$O$_3$ Electromechanical coupling factor(Kp) showed the highest value of 0.555 in the Zr/Ti=0.50/0.50 ratio ,however, dielectric constant showed the highest value of 1,217 in the Zr/Ti = 0.49/0.51 ratio. Excellent TCFr vague of 421ppm/$^{\circ}C$] at-30~9O$^{\circ}C$ was appeared in the Zr/Ti=0.50/0.50 ratio and electro-mechanical coupling factor(Kp) , mechanical quility factor(Qm) and dielectric constant was 0.496, 1,286 and 1,085 ,respectively ,in the composition ceramics of lwt%Y$_2$O$_3$ and 0.3wt%Fe$_2$O$_3$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.55-56
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• 2006

In this paper, we first applied the chemical mechanical polishing (CMP) process to the planarization of ferroelectric film in order to obtain a good planarity of electrode/ferroelectric film interface. BST ($Ba_{0.6}Sr_{0.4}TiO_3$), PZT ($Pb_{1.1}(Zr_{0.52}TiO_{0.48})O_3$) and BTO ($BaTiO_3$) ferroelectric film are fabricated by the sol-gel method. And then, we compared the structural characteristics before and after CMP process of BST, PZT, BTO films. Their dependence on slurry composition was also investigated. We expect that our results will be useful promise of global planarization for ferroelectric random access memories (FRAM) application in the near future.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.4
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• pp.77-84
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• 2015

PZT ceramics, usually used pyroelectric materials exhibited a relatively highly Curie temperture(Tc) of $250-450^{\circ}C$ and permittivity constant of 500-1600. In this paper, the pyroelectric infrared detectors are applied two different types of pyroelectric materials, that is tetragonal crystal of ferroelectric $PbTiO_3$ and rhombohedral crystal of $Pb(Zr,Ti)O_3$. PZT ceramics shows not only highly Curie temperture but also excellent pyro and piezoelectric properties at the Zr/Ti(=52/48) ratio. Therefor in this paper, the pyroelectric infrared detectors are applied PZT ceramics, and obtained sensitive sensing characteristics by expriment case studies.

• Journal of the Korean Ceramic Society
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• v.37 no.6
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• pp.530-536
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• 2000

During the grain growth of the PZT thin films by selective nucleation method using PZT seed, it was found that the grain size was saturated with the annealing temperature. The saturation of grain size was analyzed by the interfacial energy which appeared during the crystallization. The factors affecting the saturation of grain size were found to be the interfacial energy between perovskite phase and pyrochlore phase, and PZT thin film and the bottom Pt electrode. When the ion damage was introduced to the grain-size saturated PZT thin films, further lateral growth was observed. Pt bottom electrode thickness was changed to control the interfacial energy between the PZT thin film and the Pt bottom electrode. When Pt thickness was increased, the grain size was also increased, because the lattice parameter of Pt films was increased with the thickness of the Pt films. The incubation time of nucleation was increased with the amount of the ion damage on the Pt films.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.12
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• pp.549-554
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• 2006

In this paper we first applied the chemical mechanical polishing (CMP) process to the planarization of ferroelectric film in order to obtain a good planarity between electrode and ferroelectric film. $Pb_{1.1}(Zr_{0.52}Ti_{0.48})O_3$ (shortly PZT) ferroelectric film was fabricated by the sol-gel method. And then, we compared the structural characteristics before and after CMP process of PZT films. Removal rate, WIWNU% and surface roughness have been found to depend on slurry abrasive types and their hardness, especially, surface roughness and planarity were strongly depends on its pH value. A maximum in the removal rate is observed in the silica slurry, in contrast with the minimum removal rate occurs at ceria slurry. We found that the surface roughness of PZT films can be significantly reduced using the CMP technique.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.04b
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• pp.56-59
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• 2000

In this study, Ferroelectric $Pb(Zr_x,Ti_{1-x})O_3$(x=0.53) thin films were fabricated by the spin-coating on the Pt/Ti/$SiO_2$/Si substrate using the PZT metal alkoxide solutions with various excess Pb contents. Etching of PZT film was performed using planar inductively coupled Ar(20)$/Cl_2/BCl_3$ plasma. The etch rate of PZT film was 2450 ${\AA}/min$ at Ar(20)$/BCl_3$(80) gas mixing ratio and substrate temperature of $80^{\circ}C$. The leakage current densities of before etching and after etching PZT thin film were $6.25\times10^{-8}A/cm^2$, $8.74\times10^{-7}A/cm^2$ with electric field of 0.07MV/em, respectively.

• Proceedings of the KIEE Conference
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• 2001.11a
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• pp.100-102
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• 2001

In this paper, the piezoelectric and dielectric properties of $Pb(Zr_xTi_{1-x)O_3$ - $Pb(Co_{1/3}Nb_{1/3})O_3)$ piezoelectric ceramics have been investigated as a function of Zr/Ti mole ratio. From the results, when Zr/Ti mole ratio is 49/51, electromechanical coupling coefficient($k_p$), piezoelectric strain constant($d_{33}$) mechanical quality factor($Q_m$), and Permittivity(${{\varepsilon}_{33}}^T/{\varepsilon}_0$) is 64[%], 469[PC/N], 360 and 2000, respectively. Morphotropic Phase Boundary is Zr/Ti mole ratio(49/51) from XRD analysis. Also. From SEM observation, when sintering temperature is 1150[$^{\circ}C$], grain size is about $1{\sim}2[{\mu}m]$ and maximum sintering density is 7.85[$g/cm^3$].

• 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.

• Korean Journal of Materials Research
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• v.31 no.10
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• pp.546-551
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• 2021

To improve ferroelectric properties of PZT, many studies have attempted to fabricate dense PZT films. The AD process has an advantage for forming dense ceramic films at room temperature without any additional heat treatment in low vacuum. Thick films coated by AD have a higher dielectric breakdown strength due to their higher density than those coated using conventional methods. To improve the breakdown strength, glass (SiO₂-Al₂O₃-Y₂O₃, SAY) is mixed with PZT powder at various volume ratios (PZT-xSAY, x = 0, 5, 10 vol%) and coating films are produced on silicon wafers by AD method. Depending on the ratio of PZT to glass, dielectric breakdown strength and energy storage efficiency characteristics change. Mechanical impact in the AD process makes the SAY glass more viscous and fills the film densely. Compared to pure PZT film, PZT-SAY film shows an 87.5 % increase in breakdown strength and a 35.3 % increase in energy storage efficiency.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.7 no.4
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• pp.589-598
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• 1997

The effects of PT/PZ ratio variations in a modified PZT system on crystal structure and electrical properties were studied. $0.05Pb(Sn_{0.5}Sb_{0.5})O_3＋xPbTiO_3＋yPbZrO_3$＋0.4Wt% $MnO_2$(＝0.55PSS＋0.11PT＋0.84PZ＋0.4wt%$MnO_2$ ; x＋y=0.95) systems with variations of PT/PZ from 0.50/0.45 to 0.l1/0.84 were sintered at $1250^{\circ}C$ for 2 hr, and then sintering density, crystal structure, dielctric, piezoelectric, pyroelectic and voltage responsity to infrared were investigated. Sintering density was increased from 7.52g/$\textrm {cm}^3$ to 7.82g/$\textrm {cm}^3$ with increasing PZ content. Dielectric constants at 1 KHz were decreased from 1147 to 193 with variation of PT/PZ from 0.50/0.45 to 0.l1/0.84 after poling of $4 KV_{DC}$/mm at $140^{\circ}C$ for 20 minutes. All Dielectric losses at 1 KHz were less than 1 % in all specimens. $K_{p}$ was increased near to 1 of PT/PZ, and maximun value of 48.2 % was .at 0.45/0.50. Pyroelectric coefficient of PT/PZ with 0.l1/0.84 was maximun value, 0.0541 C/$\m^2$K, and voltage responsity to infrared was 1.5 V.