• Journal of the Korean Ceramic Society
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• v.36 no.10
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• pp.1035-1039
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• 1999

Ferroelectric properties and reliability characteristics of(111) and (100) preferentially oriented tetragonal Pb(Zr0.2Ti0.8)O3 (PZT) thin film capacitors have been investigated as a function of the top electrode thickness. The (111) preferentially oriented film exhibits 180$^{\circ}$domain switching process with better squareness of hysterisis loop and abrupt change of small singal capacitance-voltage comparing to the (100) preferentially oriented film having 90$^{\circ}$ domain switching process. The domain swithcing process of tetragonal phase PZT is different from that of rhobohedral phase. The film with thinner top electrode shows less initial switching polarization due to less compressive stress but it exhibits better endurance characteristics due to enhancing partial switching region.

• JSTS:Journal of Semiconductor Technology and Science
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• v.2 no.3
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• pp.205-212
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• 2002

The growth characteristics of metal-organic chemical vapor deposition (MOCVD) $Pb(Zr_xTi_{1-x})O_3 (PZT) thin films were investigated for the application of high-density ferroelectric random access memories (FRAM) devices beyond 64Mbit density. The supply control of Pb precursor plays the most critical role in order to achieve a reliable process for PZT thin film deposition. We have monitored the changes in the microstructure and electrical properties of films on increasing the Pb precursor supply into the reaction chamber. Under optimized conditions, $Ir/IrO_2/PZT(100nm)/Ir capacitor shows well-saturated hysteresis loops with a remanent polarization (Pr) of $~28{\mu}C/textrm{cm}^2$ and coercive voltage of 0.8V at 2.5V. Other issues such as step coverage, compositional uniformity and low temperature deposition was discussed in viewpoint of actual device application.

• Journal of the Korean Ceramic Society
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• v.30 no.4
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• pp.332-338
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• 1993

TiN/Ti is the best buffer layer between PZT thin film and si substrate among the Ti, TiN, ZrN, TiN/Ti, ZrN/Ti. The amorphous PZT films deposited on TiN/Ti buffer layer directly transform into perovskite phase when rapid thermal annealed for 30sec above 55$0^{\circ}C$. As Rapid Thermal Annealing(RTA) temperature increased, the remanent polarization(Pr) and dielectric constant($\varepsilon$r) increased and then showed Pr=21 $\varepsilon$r=593 when rapid thermal annealed 80$0^{\circ}C$ for 30sec. On the contrary the leakage current increased with increasing RTA temperature due to the formation of void made by Pb evaporationand grain cohesion.

• KIEE International Transactions on Electrophysics and Applications
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• v.3C no.2
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• pp.43-47
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• 2003

Lead zirconate titanate (PZT) thin films were fabricated by the pulsed laser ablation deposition (PLAD) method onto Pt/Ti/SiO$_2$/Si substrates. Crystalline phases as well as preferred orientations in PZT films were investigated by X-ray diffraction analysis (XRD). The well-crystallized perovskite phase and the (101) preferred orientation were obtained by two-step annealing at the conditions of $650^{\circ}C$, 1 hour. It was found that the temperature for the pulsed laser ablated PZT films annealed via a two-step annealing process can be reduced 20$0^{\circ}C$ compared to that of the conventional three-step annealing temperature profile for enhancing the transformation of the perovskite phase. The remanent polarization and the coercive field of this film were about 20 $\mu$C/$\textrm{cm}^2$ and 46 kV/cm, while the dielectric constant and loss values measured at 1 KHz were approximately 860 and 0.04, respectively. The interesting phenomena of this film, such as vertical shift in hysteresis curve, are also discussed.

• Proceedings of the Materials Research Society of Korea Conference
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• 1994.11a
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• pp.10-10
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• 1994

• Proceedings of the Materials Research Society of Korea Conference
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• 1999.11a
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• pp.126-126
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• 1999

• Proceedings of the Materials Research Society of Korea Conference
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• 1998.05a
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• pp.89-89
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• 1998

• Proceedings of the Materials Research Society of Korea Conference
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• 1992.05a
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• pp.41-42
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• 1992

• Proceedings of the Materials Research Society of Korea Conference
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• 1992.05b
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• pp.138-139
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• 1992

• Proceedings of the Korean Ceranic Society Conference
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• 2003.04a
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• pp.137.1-137
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• 2003