Effects of IrO2/Pt Hybrid Electrodes on the Crystallization and Ferroelectric Performances of Sol-gel-derived Pb(Zr,Ti)O3 Thin Film Capacitors

The effects of IrO2/Pt layered hybrid bottom and/or top electrode structures on the leakage current density versus voltage (J–V), polarization versus voltage (P–V), ferroelectric imprint, and fatigue properties of chemical-solution-derived Pb(ZrxTi1−x)O3 (PZT, Zr/Ti = 35/65) thin films were investigated. The best P–V and J–V performances were obtained from a capacitor with nonhybrid electrodes (Pt/PZT/Pt capacitor). However, the poor fatigue performance of the capacitor required the adoption of hybrid electrode structures. A thin IrO2 layer, as thin as 6 nm, which was inserted between top Pt electrode and PZT layer was sufficient for improving the fatigue performance without any degradation of the other ferroelectric properties. However, the same layer adopted on the bottom Pt electrode was not effective in improving the fatigue performance with degradation in P–V and J–V properties. This was ascribed to IrO2 layer dissolution into the PZT layer during the crystallization annealing of the PZT thin film. A thicker IrO2 layer resulted in more serious degradation.

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Microstructural and Ferroelectric Properties of a Chemical Solution Deposited Epitaxial PbZr0.5 Ti0.5O3 Thin Film on a SrRuO3/SrTiO3 Substrate

Journal of Materials Research ◽

10.1557/jmr.1999.0160 ◽

1999 ◽

Vol 14 (4) ◽

pp. 1190-1193 ◽

Cited By ~ 10

Author(s):

J. H. Kim ◽

A. T. Chien ◽

F. F. Lange ◽

L. Wills

Keyword(s):

Thin Film ◽

Ferroelectric Properties ◽

Chemical Solution ◽

X Ray Diffraction ◽

Solution Deposition ◽

Chemical Solution Deposition Method ◽

Transmission Electron ◽

Saturation Polarization ◽

Pzt Thin Film ◽

Relationship Of

Epitaxial PbZr0.5Ti0.5O3 (PZT) thin films were grown on top of a SrRuO3 epitaxial electrode layer on a (100) SrTiO3 substrate by the chemical solution deposition method at 600 °C. The microstructure of the PZT thin film was investigated by x-ray diffraction and transmission electron microscopy, and the ferroelectric properties were measured using the Ag/PZT/SRO capacitor structure. The PZT thin film has the epitaxial orientational relationship of (001) [010]PZT ║ (001) [010]SRO ║ (001) [010]STO with the substrate. The remnant (Pr ) and saturation polarization (Ps) density were measured to be Pr ~ 51.4 µC/cm2 and Ps ~ 62.1 µC/cm2 at 5 V, respectively. Ferroelectric fatigue measurements show that the net-switching polarization begins to drop (to 98% of its initial value) after 7 × 108 cycles.

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Effects of Rare Earth Gd Doping on Ferroelectric Properties of PbZr0.52Ti0.48O3 Thin Films Prepared by Sol–Gel Methods

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.336-338.21 ◽

2007 ◽

Vol 336-338 ◽

pp. 21-23

Author(s):

Qiu Sun ◽

Ying Song ◽

Fu Ping Wang

Keyword(s):

Thin Film ◽

Thin Films ◽

Ferroelectric Properties ◽

Sol Gel ◽

Si Substrates ◽

Low Leakage ◽

Low Leakage Current ◽

Pzt Thin Film ◽

Thermal Annealing Process ◽

Better Than

The Pb(Zr0.52Ti0.48)O3 thin films with 0-2at.%Gd dopants (denoted as PGZT) were prepared on Pt/Ti/SiO2/Si substrates by a sol-gel technique and a rapid thermal annealing process. The structures of PGZT films were characterized and the ferroelectric properties such as P–V loop, C–V and I–V characteristics were investigated. Improved polarization (2Pr = 46.373 μC/cm2) and the low leakage current (J = 1.5×10-9 A/cm2 at the electric field of 400 kV/cm) were obtained in the PZT thin film with 1at.% Gd dopant, which was better than that of the pure PZT thin film (2Pr = 39.099 μC/cm2, J = 4.3×10-8A/cm2). With the Gd contents up to 2at.%, a decreased remanent polarization was found.

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Epitaxial growth of PbZr0.5Ti0.5O3 thin films on SrRuO3/SrTiO3 substrates using chemical solution deposition: Microstructural and ferroelectric properties

Journal of Materials Research ◽

10.1557/jmr.2001.0240 ◽

2001 ◽

Vol 16 (6) ◽

pp. 1739-1744 ◽

Cited By ~ 9

Author(s):

J. H. Kim ◽

Youngman Kim ◽

A. T. Chien ◽

F. F. Lange

Keyword(s):

Thin Film ◽

Thin Films ◽

Chemical Solution Deposition ◽

Ferroelectric Properties ◽

Chemical Solution ◽

Solution Deposition ◽

Pzt Thin Films ◽

Chemical Solution Deposition Method ◽

Pzt Thin Film ◽

Film Substrate

Epitaxial PbZr0.5Ti0.5O3 (PZT) thin films were grown on top of a SrRuO3 epitaxial electrode layer on a (100) SrTiO3 substrate by the chemical solution deposition method at various temperatures. The microstructure of the PZT thin films was investigated by x-ray diffraction and transmission electron microscopy, and the ferroelectric properties were measured using the Ag/PZT/SRO capacitor structure. In the PZT thin film annealed at low temperature (450 °C/1h), both the perovskite PZT phase at the film/substrate interface and the fluorite PZT phase in the upper region of the film were obtained. It exhibited nonferroelectric properties. The PZT thin film annealed at temperature as low as 525 °C had only a perovskite tetragonal phase and the epitaxial orientational relationship of (001)[010]PZT∥(001)[010]SRO∥(001)[010]STOwith the substrate, and shows a ferroelectric property. The remnant (Pr) and saturation polarization (Ps) density of the sample annealed at 600 °C/1h were measured to be Pr ˜ 51.4 μC/cm2 and Ps ˜ 62.1 μC/cm2 at 5 V, respectively. The net switched polarization dropped only to 98% of its initial value after 7 × 108 fatigue cycles.

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The effects of cation-substitution on the ferroelectric properties of sol-gel derived PZT thin film for FRAM application

Thin Solid Films ◽

10.1016/s0257-8972(99)00375-8 ◽

1999 ◽

Vol 355-356 ◽

pp. 531-535 ◽

Cited By ~ 13

Author(s):

Woo Sik Kim ◽

Soon-Mok Ha ◽

Hyung-Ho Park ◽

Chang Eun Kim

Keyword(s):

Thin Film ◽

Ferroelectric Properties ◽

Sol Gel ◽

Cation Substitution ◽

Pzt Thin Film

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The effects of PbTiO3 thin template layer and Pt/RuO2 hybrid electrode on the ferroelectric properties of sol-gel derived PZT thin film

Thin Solid Films ◽

10.1016/s0040-6090(98)00486-6 ◽

1998 ◽

Vol 325 (1-2) ◽

pp. 72-78 ◽

Cited By ~ 21

Author(s):

Seung-Hyun Kim ◽

Yong-Soo Choi ◽

Chang-Eun Kim ◽

Doo-Young Yang

Keyword(s):

Thin Film ◽

Ferroelectric Properties ◽

Sol Gel ◽

Pzt Thin Film

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Influence of Film Texture on Reliability of Sol-Gel Derived PZT Thin-Film Capacitors

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.566.7 ◽

2013 ◽

Vol 566 ◽

pp. 7-11 ◽

Cited By ~ 1

Author(s):

Takashi Noguchi ◽

Hideaki Sakurai ◽

Jun Fujii ◽

Toshihiro Doi ◽

Toshiaki Watanabe ◽

...

Keyword(s):

Thin Film ◽

Grain Size ◽

Dielectric Breakdown ◽

Sol Gel ◽

Film Surface ◽

Deposition Process ◽

Organic Additive ◽

Time Dependent Dielectric Breakdown ◽

Thin Film Capacitors ◽

Pzt Thin Film

Time-dependent dielectric breakdown (TDDB) of lead titanate zirconate (PZT) thin-film capacitors derived by a sol-gel deposition process has been studied. Without any change in heat treatment conditions such as temperature, ramping rate, and keeping time, the films grain size was varied by adding a small amount of organic additive to PZT sol-gel solution for a control of nucleation to form PZT oxide. The reliability was remarkably improved by fabricating interfaces with multi-annealing process, parallel to film surface when the grain size is greater than film thickness, which seems to suppress conductivity of oxygen vacancies.

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The Effect of RuO2/Pt Hybrid Bottom Electrode Structure on The Microstructure and Ferroelectric Properties of Sol-Gel Derived PZT Thin Films

MRS Proceedings ◽

10.1557/proc-493-131 ◽

1997 ◽

Vol 493 ◽

Cited By ~ 8

Author(s):

Seung-Hyun Kim ◽

J. G. Hong ◽

J. C. Gunter ◽

H. Y. Lee ◽

S. K. Streiffer ◽

...

Keyword(s):

Thin Films ◽

Leakage Current ◽

Bottom Electrode ◽

Ferroelectric Properties ◽

Sol Gel ◽

Chemical Solution ◽

Electrode Structure ◽

Solution Deposition ◽

Pzt Thin Films ◽

Chemical Solution Deposition Method

ABSTRACTFerroelectric PZT thin films on thin RuO2 (10, 30, 50nm)/Pt hybrid bottom electrodes were successfully prepared by using a modified chemical solution deposition method. It was observed that the use of a lOnm RuO2Pt bottom electrode reduced leakage current, and gave more reliable capacitors with good microstructure compare to the use of thicker RuO2/Pt bottom electrodes. Typical P-E hysteresis behavior was observed even at an applied voltage of 3V, demonstrating greatly improved remanence and coercivity. Fatigue and breakdown characteristics, measured at 5V, showed stable behavior, and only below 13-15% degradation was observed up to 1010 cycles. Thicker RuO2 layers resulted in high leakage current density due to conducting lead ruthenate or PZT pyrochlore-ruthenate and a rosette-type microstructure.

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Correlations Among Degradations in Lead Zirconate Titanate thin Film Capacitors

MRS Proceedings ◽

10.1557/proc-310-165 ◽

1993 ◽

Vol 310 ◽

Cited By ~ 69

Author(s):

In K. Yoo ◽

Seshu B. Desu ◽

Jimmy Xing

Keyword(s):

Thin Film ◽

Leakage Current ◽

Lead Zirconate Titanate ◽

Oxygen Vacancies ◽

Lead Zirconate ◽

Electrical Degradation ◽

Zirconate Titanate ◽

Thin Film Capacitors ◽

Pzt Thin Film ◽

Degradation Properties

AbstractMany attempts have been made to reduce degradation properties of Lead Zirconate Titanate (PZT) thin film capacitors. Although each degradation property has been studied extensively for the sake of material improvement, it is desired that they be understood in a unified manner in order to reduce degradation properties simultaneously. This can be achieved if a common source(s) of degradations is identified and controlled. In the past it was noticed that oxygen vacancies play a key role in fatigue, leakage current, and electrical degradation/breakdown of PZT films. It is now known that space charges (oxygen vacancies, mainly) affect ageing, too. Therefore, a quantitative ageing mechanism is proposed based on oxygen vacancy migration under internal field generated by either remanent polarization or spontaneous polarization. Fatigue, leakage current, electrical degradation, and polarization reversal mechanisms are correlated with the ageing mechanism in order to establish guidelines for simultaneous degradation control of PZT thin film capacitors. In addition, the current pitfalls in the ferroelectric test circuit is discussed, which may cause false retention, imprint, and ageing.

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