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

1997 ◽  
Vol 493 ◽  
Author(s):  
Seung-Hyun Kim ◽  
J. G. Hong ◽  
J. C. Gunter ◽  
H. Y. Lee ◽  
S. K. Streiffer ◽  
...  

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.

2001 ◽  
Vol 16 (6) ◽  
pp. 1739-1744 ◽  
Author(s):  
J. H. Kim ◽  
Youngman Kim ◽  
A. T. Chien ◽  
F. F. Lange

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.


1999 ◽  
Vol 14 (11) ◽  
pp. 4395-4401 ◽  
Author(s):  
Seung-Hyun Kim ◽  
D. J. Kim ◽  
K. M. Lee ◽  
M. Park ◽  
A. I. Kingon ◽  
...  

Ferroelectric SrBi2Ta2O9 (SBT) thin films on Pt/ZrO2/SiO2/Si were successfully prepared by using an alkanolamine-modified chemical solution deposition method. It was observed that alkanolamine provided stability to the SBT solution by retarding the hydrolysis and condensation rates. The crystallinity and the microstructure of the SBT thin films improved with increasing annealing temperature and were strongly correlated with the ferroelectric properties of the SBT thin films. The films annealed at 800 °C exhibited low leakage current density, low voltage saturation, high remanent polarization, and good fatigue characteristics at least up to 1010 switching cycles, indicating favorable behavior for memory applications.


2001 ◽  
Vol 688 ◽  
Author(s):  
H. Uchida ◽  
H. Yoshikawa ◽  
I. Okada ◽  
H. Matsuda ◽  
T. Iijima ◽  
...  

AbstractBismuth titanate (Bi4Ti3O12; BIT) -based ferroelectric materials are proposed from the view of the “Site-engineering”, where the Bi-site ions are substituted by lanthanoid ions (La3+ and Nd3+) and Ti-site ions by other ions with higher charge valence (V5+). In the present study, influences of vanadium (V) - substitution for (Bi,M)4Ti3O12 thin films [M = lanthanoid] on the ferroelectric properties are evaluated. V-substituted (Bi,M)4Ti3O12 films have been fabricated using a chemical solution deposition (CSD) technique on the (111)Pt/Ti/SiO2/(100)Si substrate. Remnant polarization of (Bi,La)4Ti3O12 and (Bi,Nd)4Ti3O12 films has been improved by the V-substitution independent of the coercive field. The processing temperature of BLT and BNT films could also be lowered by the V-substitution.


1999 ◽  
Vol 14 (10) ◽  
pp. 4004-4010 ◽  
Author(s):  
J. H. Kim ◽  
F. F. Lange

Epitaxial PbZr0.5Ti0.5O3 (PZT) thin films were grown on (001) LaAlO3 substrates (∼6.1% lattice mismatch) by the chemical solution deposition method. The sequence of epitaxy during heating between 375 and 700 °C/1h was characterized by x-ray diffraction and transmission electron microscopy. At approximately 375 °C/1h, a nanocrystalline metastable fluorite phase of PZT was formed from the pyrolyzed amorphous precursor. At higher temperatures (400–425 °C/1h), thermodynamically stable PZT crystallites were first observed at the interface; with increasing higher temperatures, these nuclei grew across the interface and through the film toward the surface by consuming the metastable nanocrystalline fluorite grains. PZT thin films annealed above ∼500 °C/1h were observed to be dense with an epitaxial orientation relationship of [100](001)PZT‖[100](001)LAO. The metastable nanocrystalline fluorite to the stable single-crystal perovskite transformation gives an extra driving force by providing an additional decrease in free energy in addition to a driving force from the elimination of grain boundary area for epitaxy.


2002 ◽  
Vol 748 ◽  
Author(s):  
Dinghua Bao ◽  
Naoki Wakiya ◽  
Kazuo Shinozaki ◽  
Nobuyasu Mizutani

ABSTRACT(Bi,La)4Ti3O12 (BLT) thin films with various Bi2O3 template layers were prepared on Pt/Ti/SiO2/Si substrates by a chemical solution deposition method. Both of the BLT films with a thin Bi2O3 template layer and those without a Bi2O3 layer had a highly c-axis oriented growth, while both of the BLT films with a thin Bi2O3 bottom layer and those with a Bi2O3 intermediate layer were highly c-axis oriented. It was found that the use of Bi2O3 template layers improved significantly the ferroelectric properties of BLT thin films. In addition, the thin films with a thin Bi2O3 template layer showed good dielectric properties. All the capacitors with Bi2O3 template layers showed high polarization fatigue resistance and good retention properties.


2018 ◽  
Vol 765 ◽  
pp. 30-33
Author(s):  
Vinod Kumar ◽  
Mintu Tyagi

Magnetoelectric (1−x) BNT−xCFO nanoparticulate thin films with (x= 0, 0.1, 0.2, 0.3) were fabricated by a chemical solution deposition technique. The X-ray diffraction shows that no other secondary phases are observed. Transmission electron microscope (TEM) revels that CFO nanoparticles were well distributed in matrix of BNT. The nanocomposite films exhibit both good magnetic and ferroelectric properties at room temperature (R-T), as well as enhanced magnetoelectric coupling. The composite withx= 0.2, showed the large value ofMEvoltage coefficient (αE) ~ 163 mV/cmOe. TheseMEcomposites provide a great opportunity as potential lead free systems forMEdevices.


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