Impacts of postannealing ambient atmospheres on Pt/SrBi2.2Ta2O9/Pt capacitors

2001 ◽  
Vol 16 (12) ◽  
pp. 3526-3535 ◽  
Author(s):  
Ai-Dong Li ◽  
Tao Yu ◽  
Hui-Qin Ling ◽  
Di Wu ◽  
Zhi-Guo Liu ◽  
...  

SrBi2Ta2O9 (SBT) films were prepared on Pt/TiO2/SiO2/Si substrates at 750 °C in oxygen by the metalorganic decomposition method. SBT film capacitors were postannealed in Ar (N2) at 350–750 °C and then reannealed in O2 at 750 °C. Effects of annealing atmosphere on the structure, morphology, and ferroelectric properties have been investigated systematically. The composition analyses indicate Ar- or N2-annealing at 750 °C leads to Bi evaporation and oxygen loss. Above 550 °C 100% Ar or N2 postannealing, the remnant polarization decreases and the coercive field increases significantly. The subsequent O2 recovery can hardly rejuvenate the electrical properties. The result is different from that with the effective O2 recovery in forming gas processing (annealing in an atmosphere containing 5% hydrogen). The possible origin and mechanism is discussed and proposed.

2004 ◽  
Vol 449-452 ◽  
pp. 477-480
Author(s):  
J.H. Choi ◽  
Tae Sung Oh

Ferroelectric characteristics of the 400 nm-thick SrxBi2.4Ta2O9(0.7≤x≤1.3) thin films processed by metalorganic decomposition were investigated, and electrical properties of the Pt/Sr0.85Bi2.4Ta2O9/TiO2/Si structure prepared using TiO2 buffer layer were characterized. The Sr-deficient SrxBi2.4Ta2O9 films exhibited well-developed ferroelectric hysteresis curves compared to those of the Sr-excess films. The Sr0.85Bi2.4Ta2O9 film exhibited optimum ferroelectric properties, such as high remanent polarization and low leakage current density, among SrxBi2.4Ta2O9 films. A memory window of the Pt/SrxBi2.4Ta2O9/TiO2/Si structure was dependent upon the coercive field of the SrxBi2.4Ta2O9 film, and the Pt/SrxBi2.4Ta2O9/TiO2/Si exhibited a maximum memory window of 1.3 V at the sweeping voltage of ±5 V.


2014 ◽  
Vol 633 ◽  
pp. 378-381
Author(s):  
Bei Li ◽  
X.B. Liu ◽  
M. Chen ◽  
X.A. Mei

Dy-doped Bi4Ti3O12 thin films were fabricated on Pt/Ti/SiO2/Si substrates by pulsed laser deposition technique, and the structures and electrical properties of the films were investigated. XRD results indicated that all of Bi4-xDyxTi3O12 films consisted of single phase of a bismuth-layered structure with well-developed rod-like grains. The remanent polarization ( Pr ) and coercive field (Ec) of the Bi4-xDyxTi3O12 Film with x=0.75 were 25μC/cm2 and 85KV/cm , respectively.


2014 ◽  
Vol 703 ◽  
pp. 51-55
Author(s):  
Jia Zeng ◽  
Ming Hua Tang ◽  
Zhen Hua Tang ◽  
Yong Guang Xiao ◽  
Long Peng ◽  
...  

Bi0.94Ce0.06Fe0.97Ti0.03O3 and Bi0.94Ce0.06Fe0.97Ti0.03O3/Bi3.15Nd0.85Ti3O12 double-layered thin films were fabricated via sol-gel process on Pt/Ti/SiO2/Si substrates. The influence of Bi3.15Nd0.85Ti3O12 buffer layer on microstructure and electrical properties of Bi0.94Ce0.06Fe0.97Ti0.03O3 thin films were investigated in detail. Well-saturated P-E hysteresis loops can be obtained in Bi0.94Ce0.06Fe0.97Ti0.03O3 films with Bi3.15Nd0.85Ti3O12 buffer. The remnant polarization (2Pr) of the double-layered thin films is 112 μC/cm2. The coercive field (2Ec) of double-layered films is 672 kV/cm, which is much lower than that of the Bi0.94Ce0.06Fe0.97Ti0.03O3 thin films. The leakage current density of Bi0.94Ce0.06Fe0.97Ti0.03O3/Bi3.15Nd0.85Ti3O12 double-layered thin films is 4.12×10-5 A/cm2.


2002 ◽  
Vol 747 ◽  
Author(s):  
Eisuke Tokumitsu ◽  
Masahito Kishi

ABSTRACTWe have characterized (Sr,Sm)Bi2Ta 2O9 (SSBT) films fabricated by the sol-gel technique on Pt/Ti/SiO2/Si substrates. For ferroelectric-gate FET applications, a ferroelectric film which has a small remanent polarization and a relatively large coercive field is required. It is demonstrated that Sm doping in ferroelectric SBT films is effective to reduce the remanent polarization and enhance the coercive field. Sr0.5Sm0.2Bi2.2Ta2O9 films (150nm) crystallized at 850°C exhibits good electrical properties with a remanent polarization of 1.7 μC/cm2 and a coercive fields of 85 kV/cm. These values are suitable for ferroelectric-gate FET applications.


2005 ◽  
Vol 902 ◽  
Author(s):  
Sushil Kumar Singh ◽  
Hiroshi Ishiwara

AbstractMn-doped Bi3.25La0.75Ti3O12 (BLT) thin films were fabricated by depositing sol-gel solutions on Pt/Ti/SiO2/Si <100> substrates. The surface morphology and ferroelectric properties of Mn-doped BLT films depend upon the orientation of the films. Small amount of Mn-doping in BLT films influences the ferroelectric properties of the films, that is, it enhances the remanent polarization and reduces the coercive field. The 1% Mn-doped BLT films show enhanced remanent polarization and reduced the coercive field by about 22%. To the contrary, Mn-doping more than 1% decreases polarization gradually. Mn-doping significantly improves the fatigue resistance of BLT films. The reduced polarization in the 3.3% Mn-doped thin film recovers during switching cycles higher than 5 × 105. Under high switching field, the probability of field-assisted unpinning of domains is expected to be high and this may be the main cause for increase in polarization after 5 × 105 in the 3.3% Mn-doped BLT film.


1995 ◽  
Vol 415 ◽  
Author(s):  
T. Ami ◽  
K. Hironaka ◽  
C. Isobel ◽  
N. Nagel ◽  
M. Sugiyama ◽  
...  

ABSTRACTFerroelectric Bi2 SrTa2 O9 thin films were successfully prepared by liquid delivery MOCVD, and structural and electrical properties were investigated. As-deposited films showed sharp distinct peaks, which were indexed assuming a fluorite-type structure. These precursors were transformed to bismuth-layered structures by annealing at 800 °C in flowing oxygen. Reasonable ferroelectric properties were observed in a film with 170 nm-thickness. Remanent polarization and coercive field were estimated to be 5.2 μC/cm2 and 52 kV/cm, respectively, at 5V.


2006 ◽  
Vol 21 (12) ◽  
pp. 3124-3133 ◽  
Author(s):  
Fan-Yi Hsu ◽  
Ching-Chich Leu ◽  
Chao-Hsin Chien ◽  
Chen-Ti Hu

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.


2009 ◽  
Vol 421-422 ◽  
pp. 148-152
Author(s):  
Yuki Hasegawa ◽  
Masafumi Kobune ◽  
Yusuke Daiko ◽  
Atsushi Mineshige ◽  
Tetsuo Yazawa ◽  
...  

On the basis of experimental data on the piezoelectric pinpoint composition of ceramics of the ternary system Pb(Mg1/3Nb2/3)O3-PbZrO3-PbTiO3 (PMNZT), which we investigated in our previous report, epitaxial PbMg0.047Nb0.095Zr0.416Ti0.442O3 thick films with thicknesses ranging from 0.4 to 1.9 m were fabricated on Pt(100)/MgO(100) substrates by metalorganic decomposition. The film- thickness dependence on the structural and electrical properties (dielectric, piezoelectric and ferroelectric properties) was investigated. All PMNZT films exhibited a highly uniform (001) orientation, regardless of the film thickness. The cross-sectional transmission electron microscope micrographs and all the physical data suggest that high-density PMNZT thick films with a thickness  1.0 m can be expected to function as highly electrically insulating capacitors with high potential for piezo- and ferroelectric applications.


1994 ◽  
Vol 361 ◽  
Author(s):  
Kazushi Amanuma ◽  
Takashi Hase ◽  
Yoicht Mtyasaka

ABSTRACTStructural and electrical properties were investigated for chemically prepared SrBi2Ta2O9(SBT) thin films on Pt/Ti/SiO2/Si substrates. Good ferroelectric properties were obtained with a Pt top electrode: Pr=10.0μC/cm2 and Ec-34kV/cm. Au top electrodes resulted in smaller Pr. However, no fatigue was observed up to 109 switching cycles regardless of the top electrode material. Grains were spherical, not columnar, and the average grain size was 200nm. A marked structural change took place in the bottom Pt/Ti electrode during film preparation. The SIMS analysis indicates the reaction between Bi and Pt


2008 ◽  
Vol 368-372 ◽  
pp. 100-102 ◽  
Author(s):  
Su Hua Fan ◽  
Jing Xu ◽  
Guang Da Hu ◽  
Bo He ◽  
Feng Qing Zhang

Ca1-xSrxBi4Ti4O15 thin films were fabricated by sol-gel method on Pt(100)/Ti/SiO2/Si substrates. Influence of Sr content on the microstructure and ferroelectric properties of Ca1-xSrxBi4Ti4O15 thin films were systematically studied. The results indicate that Ca0.4Sr0.6Bi4Ti4O15 thin film has better ferroelectric properties with remanent polarization (2Pr) of 29.1+C/cm2, coercive field (2Ec) of 220 kV/cm. Furthermore, the film has good fatigue resistance. The better ferroelectric properties of Ca0.4Sr0.6Bi4Ti4O15 thin film originate from the relatively high concentration of a-axis oriented grains.


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