Preparation and Properties of ferroelectric Bi2SrTa2O9 thin films for FeRAM using Flash-MOCVD

1995 ◽  
Vol 415 ◽  
Author(s):  
T. Ami ◽  
K. Hironaka ◽  
C. Isobel ◽  
N. Nagel ◽  
M. Sugiyama ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Coercive Field ◽  
Remanent Polarization ◽  
Ferroelectric Properties ◽  
Type Structure ◽  
Structural And Electrical Properties ◽  
Fluorite Type ◽  
Deposited Films ◽  
Flowing Oxygen

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.

Enhanced Electrical properties in Mn-doped Bi3.25La0.75Ti3O12 thin films

2005 ◽  
Vol 902 ◽  
Author(s):  
Sushil Kumar Singh ◽  
Hiroshi Ishiwara
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electrical Properties ◽  
Coercive Field ◽  
Remanent Polarization ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Switching Field ◽  
Mn Doping ◽  
Mn Doped

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.

Ferroelectric Characteristics of SrxBi2.4Ta2O9 Thin Films and Electrical Properties of the Pt/SrxBi2.4Ta2O9/TiO2/Si Structure

2004 ◽  
Vol 449-452 ◽  
pp. 477-480
Author(s):  
J.H. Choi ◽  
Tae Sung Oh
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Coercive Field ◽  
Remanent Polarization ◽  
Ferroelectric Properties ◽  
Memory Window ◽  
Low Leakage ◽  
Low Leakage Current ◽  
Metalorganic Decomposition ◽  
Ferroelectric Hysteresis

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.

Ferroelectric Properties and Microstructures of Bi4-xDyxTi3O12 Thin Films

2014 ◽  
Vol 633 ◽  
pp. 378-381
Author(s):  
Bei Li ◽  
X.B. Liu ◽  
M. Chen ◽  
X.A. Mei
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Layered Structure ◽  
Remanent Polarization ◽  
Single Phase ◽  
Ferroelectric Properties ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Deposition Technique ◽  
Si Substrates

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.

scholarly journals STRUCTURAL AND ELECTRICAL PROPERTIES OF TANTALUM PENTAOXIDE (Ta2O5) THIN FILMS – A REVIEW

2013 ◽  
Vol 22 ◽  
pp. 564-569
Author(s):  
KANTA RATHEE ◽  
B. P. MALIK
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Electrical Properties ◽  
Metal Oxide ◽  
High Dielectric Constant ◽  
Complementary Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Structural And Electrical Properties ◽  
High Dielectric ◽  
Deposited Films

Down scaling of complementary metal oxide semiconductor transistors has put limitations on silicon dioxide to be used as an effective dielectric. It is necessary to replace the SiO 2 with a physically thicker layer of oxides of high dielectric constant. Thus high k dielectrics are used to suppress the existing challenges for CMOS scaling. Many new oxides are being evaluated as gate dielectrics such as Ta2O5 , HfO2 , ZrO2 , La2O3 , HfO2 , TiO2 , Al2O3 , Y2O3 etc but it was soon found that these oxides in many respects have inferior electronic properties to SiO2 . But the the choice alone of suitable metal oxide with high dielectric constant is not sufficient to overcome the scaling challenges. The various deposition techniques and the conditions under which the thin films are deposited plays important role in deciding the structural and electrical properties of the deposited films. This paper discusses in brief the various deposition conditions which are employed to improve the structural and electrical properties of the deposited films.

0.75SrBi2Ta2O9-0.25Bi3TiTaO9 Layered Structural Thin Films: Microstructure and Ferroelectric Properties

2008 ◽  
Vol 368-372 ◽  
pp. 1814-1816
Author(s):  
Dan Xie ◽  
Zhi Gang Zhang ◽  
Tian Ling Ren ◽  
Li Tian Liu
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Grain Size ◽  
Coercive Field ◽  
Remanent Polarization ◽  
Ferroelectric Properties ◽  
Significant Enhancement ◽  
Solution Deposition ◽  
Annealing Temperatures

{0.75SrBi2Ta2O9-0.25Bi3TiTaO9}(SBT-BTT) thin films were prepared by the modified metalorganic solution deposition (MOSD) technique. The microstructure and ferroelectric properties of SBTBTT thin films were studied. The SBT-BTT thin films were produced at 750°C. The grain size and surface roughness of SBT-BTT films showed significant enhancement with an increase in annealing temperatures. It is found that SBT-BTT thin films have good ferroelectric properties. The measured remanent polarization values for SBT-BTT, SBT and BTT capacitors were 15, 7.5 and 4.8μC/cm2, respectively. The coercive field for SBT-BTT capacitors was 50kV/cm. More importantly, the polarization of SBT-BTT capacitors only decreased 5% after 1011 switching cycles at a frequency of 1MHz.

Investigation of the Structural and Microstructural Characteristics of Sol-Gel Derived Lead Lanthanum Titanate Thin Films

1999 ◽  
Vol 596 ◽  
Author(s):  
S. B. Majumder ◽  
S. Bhaskar ◽  
P. S. Dobal ◽  
A. L. Morales. Cruz ◽  
R. S. Katiyar
Keyword(s):  
Thin Films ◽  
Acetic Acid ◽  
Electrical Properties ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Sharp Decrease ◽  
Modified Technique ◽  
Lanthanum Titanate ◽  
La Addition ◽  
Deposited Films

AbstractIn the present work we have studied the characteristics of Pb1.05-xLaxTil-x/4O3 ( x= 0 to 30 at%) thin films prepared by acetic acid and methoxy-ethanol based sol-gel techniques. We have found that higher intermediate temperature fired films (x=0.15), prepared by acetic acid modified technique yielded (100) textured growth with improved dielectric properties. It has been argued that homogeneous mixing of the film constituents in the sol is influenced by the choice of the precursor materials and preparation methodology which in turn controls the growth characteristics and electrical properties. Lanthanum as a dopant has a pronounced influence on the structure, microstructure and electrical properties of the deposited films. In the Raman spectra, the soft E(1TO) phonon shifts towards the lower frequency with a sharp decrease in its intensity and a tetragonal to cubic structural transformation (for 26.5 at % La) was observed at room temperature. In the ferroelectric composition range (up to 15 at % La doping), we have observed a significant improvement of ferroelectric properties with the La addition.

Control of Grain Size of Pb(Zr,Ti)O3 Thin Films by MOCVD and the Effect of Size on the Electrical Properties

1998 ◽  
Vol 541 ◽  
Author(s):  
H. Fujisawa ◽  
S. Nakashima ◽  
M. Shimizu ◽  
H. Niu
Keyword(s):  
Thin Films ◽  
Growth Rate ◽  
Grain Size ◽  
Electrical Properties ◽  
Coercive Field ◽  
Remanent Polarization ◽  
Dielectric Constants ◽  
Pzt Thin Films ◽  
Pzt Films

AbstractThe grain size of MOCVD-Pb(Zr,Ti)O3 (PZT) thin films was successfully controlled by changing the grain size of Ir bottom electrodes and by changing the growth rate of PZT films. In Ir/PZT/Ir/SiO2/Si capacitors, the grain size of PZT thin films increased from 120 to 240nm as the grain size of bottom Ir electrodes increased from 50 to 200nm. The dielectric constants of PZT thin films increased from 760 to 1440 as the grain size increased from 120 to 240nm. Remanent polarization increased and coercive field decreased as the grain size increased. This dependence of electrical properties on the grain size coincided with that of ceramics.

ELECTRICAL PROPERTIES OF HETEROLAYERED BaTiO3/(Bi1/2Na1/2)TiO3 THICK FILMS

2009 ◽  
Vol 23 (31n32) ◽  
pp. 3785-3791
Author(s):  
SUNG-PILL NAM ◽  
HYUN-JI NOH ◽  
SUNG-GAP LEE ◽  
SEON-GI BAE ◽  
YOUNG-HIE LEE
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Electrical Properties ◽  
Screen Printing ◽  
Remanent Polarization ◽  
Ferroelectric Properties ◽  
Thick Films ◽  
Rhombohedral Structure ◽  
Structural And Electrical Properties ◽  
Printing Techniques

The heterolayered BT/BNT thick films were fabricated by screen printing techniques on alumina substrates electrodes with Pt . Their structure and ferroelectric properties were investigated with the heterolayered tetragonal/rhombohedral structure composed of the BT and the BNT thick films. The structural and electrical properties of the heterolayered BT/BNT thick films were studied. The dielectric properties such as dielectric constant, loss and remanent polarization of the heterolayered BT/BNT thick films were superior to those of single composition BNT, and those values for the heterolayered BT/BNT thick films were 1455, 0.025 and 12.63 µC/cm2.

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.

Structural and Ferroelectric Properties of SrBi2Ta2O9 Thin Films

1994 ◽  
Vol 361 ◽  
Author(s):  
Kazushi Amanuma ◽  
Takashi Hase ◽  
Yoicht Mtyasaka
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Structural Change ◽  
Electrical Properties ◽  
Ferroelectric Properties ◽  
Si Substrates ◽  
Average Grain Size ◽  
Structural And Electrical Properties ◽  
Sims Analysis ◽  
Film Preparation

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

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