Analysis of the Dependence of Ferroelectric Properties of Strontium Bismuth Tantalate (SBT) Thin Films on the Composition and Process Temperature

1996 ◽  
Vol 35 (Part 1, No. 9B) ◽  
pp. 4900-4904 ◽  
Author(s):  
Takehiro Noguchi ◽  
Takashi Hase ◽  
Yoichi Miyasaka
Keyword(s):  
Thin Films ◽  
Ferroelectric Properties ◽  
Process Temperature ◽  
Strontium Bismuth Tantalate

Processing effects on the microstructure and ferroelectric properties of strontium bismuth tantalate thin films

2002 ◽  
Vol 75 (5) ◽  
pp. 607-615 ◽  
Author(s):  
R. Jiménez ◽  
C. Alemany ◽  
M.L. Calzada ◽  
A. González ◽  
J. Ricote ◽  
...  
Keyword(s):  
Thin Films ◽  
Ferroelectric Properties ◽  
Strontium Bismuth Tantalate ◽  
Processing Effects

Composition Dependence of Dielectric Anomaly in Strontium Bismuth Tantalate Thin Films

1998 ◽  
Vol 541 ◽  
Author(s):  
Koichi Takemura ◽  
Takehiro Noguchi ◽  
Takashi Hase ◽  
Hidekazu Kimura ◽  
Yoichi Miyasaka
Keyword(s):  
Thin Films ◽  
Temperature Dependence ◽  
Local Structure ◽  
Remanent Polarization ◽  
Composition Dependence ◽  
Lattice Structure ◽  
Ferroelectric Properties ◽  
Dielectric Anomaly ◽  
Strontium Bismuth Tantalate ◽  
First Order

AbstractEffects of off-stoichiometry and Nb substitution on the dielectric anomaly and ferroelectric properties have been investigated for SrBi2Ta2O9(SBT) thin films. Local atomic environment for the stoichiometric and off-stoichiometric SBT films has been also measured. The features of the dielectric anomaly, the Curie temperature (Tc), and the temperature dependence of the spontaneous polarization (Ps) are independent of the film thickness, and are governed by the nature of the crystal. For the stoichiometric Sr content SBT films, the grain size increases and the temperature dependence of the remanent polarization (Pr) decreases with increasing thickness. For the films with Sr/Bi/Ta = 0.8/2/2 and 0.8/2.2/2, Sr deficient local structure was observed, and such lattice structure probably leads to higher Tc than the stoichiometric crystal. Nb substitution for Ta also raises Tc, and makes the dielectric anomaly sharper. The phase transition associated with the dielectric anomaly for these films is thought to be first-order.

Influence of Ta content on the physical properties of SrBi2Ta2O9 ferroelectric thin films

2006 ◽  
Vol 21 (12) ◽  
pp. 3124-3133 ◽  
Author(s):  
Fan-Yi Hsu ◽  
Ching-Chich Leu ◽  
Chao-Hsin Chien ◽  
Chen-Ti Hu
Keyword(s):  
Thin Films ◽  
Physical Properties ◽  
Spin Coating ◽  
Coercive Field ◽  
Remanent Polarization ◽  
Ferroelectric Properties ◽  
Ferroelectric Thin Films ◽  
Preferential Orientation ◽  
Strontium Bismuth Tantalate ◽  
Metalorganic Decomposition

We have investigated the effect that the Ta content has on the ferroelectric properties of strontium bismuth tantalate (SBT) thin films synthesized using metalorganic decomposition (MOD) and spin coating techniques. The physical properties of these SBT samples were strongly dependent upon the Ta ratio. Polarization measurements revealed that Ta-deficient SBT exhibited a relatively low coercive field (2Ec ∼ 87 kV/cm) and a high remanent polarization (2Pr ∼ 15 μC/cm2). The value of 2Pr decreased as the Ta ratio in SBT increased. The improved ferroelectric properties of the Ta-deficient SBT samples may have resulted from the uniformly well-grown bismuth-layered-structured (BLS) phases of the films and their highly preferential orientation along the a and b axes. We suggest that the incorporation of Ta vacancies plays an important role in enhancing the crystallinities and microstructures of Ta-deficient SBT films.

Improvement in Ferroelectric Properties of Sol-Gel Derived SrBi2Ta2O9 thin films with seeding layers

2002 ◽  
Vol 718 ◽  
Author(s):  
Ching-Chich Leu ◽  
Chao-Hsin Chien ◽  
Ming-Jui Yang ◽  
Ming-Che Yang ◽  
Tiao-Yuan Huang ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Magnetron Sputtering ◽  
Remanent Polarization ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Strontium Bismuth Tantalate ◽  
Seeding Layer ◽  
Si Substrates ◽  
Nucleation Sites

AbstractThe effects of a seeding layer, which was deposited on Pt/TiO2/SiO2/Si substrates using magnetron sputtering, on the characteristics of sol-gel-deposited strontium-bismuth-tantalate (SBT) thin films are investigated. The seeding layer serves as nucleation sites so homogeneous crystalline SBT films of bismuth-layered structure (BLS) with fine grains are successfully obtained by 750°C rapid thermal annealing in O2 ambient. The remanent polarization (2Pr) improves from 12.1 to 18.8 μC/cm2 with the addition of the seeding layer. In addition, the seeding layer also results in a lower nucleation temperature, allowing the use of 700°C annealing for 10 min to grow SBT films that are fully crystallized with BLS phase and shows good ferroelectric properties. Finally, crystallinity and microstructures of SBT films are found to be strongly dependent on the thickness of the seeding layer. Optimum Ta-seeded SBT thin film crystallized at 700°C for 10min depicts a higher 2Pr value (12.9 μC/cm2 (@5V) than that of the un-seeded films crystallized at 750°C for 1min.

An optimized process for fabrication of SrBi2Ta2O9 thin films using a novel chemical solution deposition technique

1999 ◽  
Vol 14 (11) ◽  
pp. 4395-4401 ◽  
Author(s):  
Seung-Hyun Kim ◽  
D. J. Kim ◽  
K. M. Lee ◽  
M. Park ◽  
A. I. Kingon ◽  
...  
Keyword(s):  
Thin Films ◽  
Chemical Solution Deposition ◽  
Low Voltage ◽  
Ferroelectric Properties ◽  
Chemical Solution ◽  
Solution Deposition ◽  
Chemical Solution Deposition Method ◽  
Low Leakage ◽  
Low Leakage Current ◽  
Voltage Saturation

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.

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