• Korean Journal of Materials Research
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• v.10 no.10
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• pp.684-690
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• 2000

In order to study effects of interfacial layers between $Pb(Zr,Til)Q_3(PZT)$ films and electrodes for Metal-Ferroelectric-MetaI(MFM) structure capacitors, we have fabricated the capacitors with the Pt/PZT/interfacial-layer/Pt/$TiO_2/SiO_2$/Si structure. $PbTiO_3(PT)$ interfacial layers were formed by sol-gel deposition and PbO, ZrO, and $TiO_2$ thin layers were deposited by reactive sputtering. $TiO_2$ interface layers result in the finest grains of PZT(crystalline Temp. $600^{\circ}C$) films compare to $PbO_2\;and\;ZrO_2$ layers. However, as the thickness of $TiO_2$ layer increases. PZT thin films become rough and electrical characteristics were deteriorated due to remained anatase phase. On the other hand. PT interface layers result in improved morphology of PZT films and do not significantly change ferroelectric properties. It is a also observed that seed layers at the middle and top of PZT films do not give significant effects on grain size but the PT seed layer at the interface between the bottom electrode and the PZT films results in the small grain size.

• Electrical & Electronic Materials
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• v.10 no.10
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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.

• 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.

• Korean Journal of Materials Research
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• v.8 no.12
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• pp.1170-1175
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• 1998

PZT films without lower electrode were deposited on the highly doped Si(100) substrate with MgO buffer layer (Mgo/si) by RF magnetron sputtering method followed by the rapid thermal annealing at $650^{\circ}C$ . We investigated the dependences of the crystalline and electrical properties on the MgO thickness and the RTA post annealing. The PZT films on bare Si (without MgO) showed pyrochlore crystal structure while those on MgO(50 )/Si substrates showed the typical perovskite crystal structures. From SEM and AES analysis, the thickness of PZT films was about 7000 showing relatively smooth interface. The depth profiles indicated that atomic species were distributed homogeneously in the PZT/MgO/Si substrate. The dielectric constant($\varepsilon_{r}$ ) and remanent polarization(2Pr) were about 300 and $14\mu$C/$\textrm{cm}^2$;, respectively. The leakage current was about $3.2\mu$/A$\textrm{cm}^2$.

• Korean Journal of Materials Research
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• v.8 no.12
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• pp.1152-1157
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• 1998

The PZT films were deposited on the Pt/Ti/$SiO_2$/Si substrates using multi- target DC magnetron reactive sputtering. The perovskite single phase with the composition close to the stoichiometric one, was obtained even at high substrate temperature of $540^{\circ}C$ by 2-step method, which is that PZT film was deposited for a short time at low substrate temperature ($480^{\circ}C$) to promote the nucleation of perovskite phase by reducing the volatility of Pb oxide molecules, followed by the deposition at the elevated temperature to suppress the excess incorporation of Pb component in the PZT film. This two-step method, in combination with the RTA treatment, gives rise to good electrical properties of the deposited PZT films: remanent polarifaion,$18\mu$C/$\textrm{cm}^2$; coercive field, 45kV/cm; leakage current of 10$^{-4}$ A/$\textrm{cm}^2$ at high electric field of -500kV/cm.

• Journal of the Microelectronics and Packaging Society
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• v.11 no.3 s.32
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• pp.91-97
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• 2004

PBT thin films were formed by rf-magnetron sputtering on $Pt/Ti/SiO_2/Si$ substrate. Bulk-PZT target containing $5\%$-excess PbO was used. After PZT thin films had been deposited at room temperature, remaining portion of the thin film was formed by in-situ process. The ferroelectric perovskite phase was formed at $650^{\circ}C$. The leakage current property was improved dramatically by 2-step sputtering, and in the sample containing optimum thickness of room temp.-layer very low leakage current of $2{\times}10^{-7}A/cm^2$ was shown. As a result of the investigation on the leakage current mechanism, the electrical conduction mechanism in all PZT thin films formed by several conditions was confirmed as bulk-limited mechanism.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.245-248
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• 2012

In this paper, the optimized growing conditions of PZT thin films on low temperature co-fired ceramics (LTCC) substrates are studied. The LTCC technology is an emerging one in the fields of mesoscale (from 10 um to several hundred um) sensor and actuator against silicon based technology due to low cost, high yield, easy manufacturing of 3 dimensional structure, etc. The LTCC substrates with thickness of 400 um are fabricated by laminating 100 um green sheets using commercial power (NEG, MLS 22C). The Pt/Ti bottom electrodes are deposited on the LTCC substrates, then the growing conditions of PZT thin films using rf magnetron sputtering method are studied. The growing conditions are tested under various rf power and gas ratio of oxygen to argon. And the crystallization and ingredient of PZT films are analyzed by X-ray diffraction method (XRD) and energy dispersive spectroscopy (EDS). The optimized growing conditions of PZT thin films are rf power of 125W, Ar/O2 gas ratio of 15:5.

• Journal of the Korean Magnetics Society
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• v.15 no.1
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• pp.21-24
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• 2005

This work is to present each properties and the interfacial characterization between PZT layer and LSMO layer of PZT/LSMO/Pt. LSMO thin film grown by KrF(248 nm) excimer lasers are used in pulsed in pulsed laser deposition(PLD). PZT coposites thin films were deposited by spin coating using a commercial resist spinner. LSMO thin film by deposition oxygen pressure 125 mtorr have rhombohedral structure on Pt(111) substrate. The PZT/LSM/Pt pre-orientate to [111] direction. The final thin films were shown that magnetic and electric property was typical value, respective. We report that the lattice between the PZT/LSMO thin film and the substrate plays a very important role and may control to another effects.

• Proceedings of the Korean Ceranic Society Conference
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• 2000.10a
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• pp.144.2-144
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• 2000

• Proceedings of the Materials Research Society of Korea Conference
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• 1997.05a
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• pp.51-51
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• 1997