Low-Frequency Dielectric Properties of Sol-Gel Derived BaTiO3 Thin Films

1998 ◽  
Vol 541 ◽  
Author(s):  
Su-Jae Lee ◽  
Kwang-Yong Kang ◽  
Jin-Woo Kim ◽  
Seok Kil Han ◽  
Sang-Don Jeong
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Space Charge ◽  
Dielectric Relaxation ◽  
Sol Gel ◽  
Oscillation Amplitude ◽  
Low Frequency ◽  
Relative Dielectric Constant ◽  
Charge Carriers ◽  
Si Substrates

AbstractFerroelectric BaTiO 3 thin films with perovskite structure were grown by sol-gel spin-on processing onto (111)Pt/Ti/SiO2/Si substrates. In order to investigate the effects of space charge in BaTiO3 thin films, we measured the relative dielectric constant and the ac conductivity of the films as a function of frequency, ac oscillation amplitude and temperature. Dielectric constant and dielectric loss were 147 and 0.03 at 100 kHz, respectively. Also, BaTiO3 thin films exhibited marked dielectric relaxation above the Curie temperature and in the low frequency region below 100 Hz. This low frequency dielectric relaxation is attributed to the ionized space charge carriers such as oxygen vacancies and defects in BaTiO3 film and the interfaical polarization. The thermal activation energy for the relaxation process of the ionized space charge carriers was 0.72 eV.

Electrical Properties Optimization of Ba0.9Sr0.1TiO3 Thin Films Deposited by Sol-Gel

2011 ◽  
Vol 277 ◽  
pp. 1-10 ◽  
Author(s):  
D. Fasquelle ◽  
M. Mascot ◽  
J.C. Carru
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Electrical Properties ◽  
Annealing Time ◽  
Remnant Polarization ◽  
Sol Gel ◽  
Si Substrates ◽  
Annealing Temperatures ◽  
Annealing Conditions ◽  
Average Size

This paper reports a study of Ba0.9Sr0.1TiO3films deposited on Pt/Ti/SiO2/Si substrates. The annealing temperatures were 750°C, 850°C and 950°C. An increase of the average size of grains was observed, from 60 nm at 750°C to 110 nm at 950°C, as well as an increase of the dielectric constant, remnant polarization and tunability. When the annealing time was decreased from 1 hour to 15 min, the dielectric constant and remnant polarization values have been increased. The optimized annealing conditions (950°C for 15 min) give the following results: εr= 780 and tgδ = 0.01 at 100 kHz, Pr = 13 µC/cm², Ec = 63 kV/cm and a tunability of 55%.

SrTiO3 Films Prepared by MOCVD Using Novel Sr Source

1994 ◽  
Vol 361 ◽  
Author(s):  
Hideaki Yamauchi ◽  
Takafumi Kimura ◽  
Masao Yamada
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
Thick Films ◽  
Relative Dielectric Constant ◽  
Si Substrates ◽  
Vaporization Temperature

ABSTRACTSrTiO3 thin films have been prepared by MOCVD. A novel Sr source of Sr(DPM)2-tetraen2 was used to stabilize source delivery and to reduce the vaporization temperature of Sr source. Films were deposited on Pt/Ta/Si substrates at deposition temperatures from 450 °C to 600 °C. The relative dielectric constant was about 220 at the deposition temperatures from 550 °C to 600 °C for as-deposited 90-nm-thick films. The leakage current density was in the range of 10−7 A/cm2, typically.

Structural and Electrical Properties of BaTio3 Thin Films Grown on p-Si Substrates with Different Device Designs

1993 ◽  
Vol 318 ◽  
Author(s):  
L. H. Chang ◽  
Q. X. Jia ◽  
W. A. Anderson
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Leakage Current ◽  
Single Layer ◽  
Relative Dielectric Constant ◽  
Rf Magnetron Sputtering ◽  
Phonon Modes ◽  
Si Substrates ◽  
Low Leakage ◽  
Low Leakage Current

ABSTRACTRF magnetron sputtering of BaTiO3 on (100) p-Si was performed to produce a high-quality BaTiO3/p-Si interface and BaTi03 insulator gates with high dielectric constant and low leakage current. Through different processing and device designs, different capacitor structures, including single layer amorphous, single layer polycrystalline and bi-layer amorphous on polycrystal-line, were investigated in this study. Raman spectroscopy showed the optical phonon modes of the BaTiO3 thin films with different structures. The structural properties of the films were characterized by X-ray diffraction. Using both the quasistatic and the high-frequency capacitance-voltage measurements, the interface-trap density was estimated at high 1011 eV−1 cm−2. The relative dielectric constant of the composite structure was controlled in a range from 30 to 130. The leakage current density was as low as 8×10−10 A/cm2 at a field intensity of (2±0.5)×105 V/cm. Breakdown voltage varied from 5x105 to 2×106 V/cm.

The Dielectric Tunability of Fe-Doped Pb0.3Sr0.7TiO3 Thin Films Prepared by Sol-Gel Method

2011 ◽  
Vol 399-401 ◽  
pp. 958-962
Author(s):  
Xiao Hua Sun ◽  
Shuang Hou ◽  
Xiu Leng Li ◽  
Tian You Peng ◽  
Xing Zhong Zhao
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Dielectric Loss ◽  
Sol Gel ◽  
Gel Method ◽  
Sol Gel Method ◽  
Force Microscopy ◽  
Si Substrates ◽  
Fe Content ◽  
Metal Insulator Metal

Fe-doped Pb0.3Sr0.7TiO3 (PST) thin films have been fabricated on Pt/Ti/SiO2/Si substrates with sol–gel method. The structure and surface morphology of Fe-doped PST thin films were investigated as a function of Fe concentration by x-ray diffraction (XRD) and atomic force microscopy (AFM). The dielectric measurements were conducted on metal-insulator-metal capacitors at the frequency from 100 Hz to 1M Hz at room temperature. It’s found that the dielectric constant, dielectric loss and tunability of Fe-doped PST films decreased with the increase of Fe content. The effects of Fe doping on the microstructure, dielectric and tunable properties of thin films were analyzed. Though the undoped PST thin film exhibited the highest dielectric constant of 2011 and the largest tunability of 76%, the 6 mol% Fe doped PST thin films had the highest figure of merit (FOM) of 17.9 for its lowest dielectric loss.

DIELECTRIC BEHAVIORS OF ZnFe2O4 – SiO2 COMPOSITE THIN FILMS PREPARED BY SOL-GEL METHOD

2005 ◽  
Vol 19 (15n17) ◽  
pp. 2682-2686 ◽  
Author(s):  
H. JIANG ◽  
H. W. LIU ◽  
H. YU ◽  
F. GAO ◽  
J.-M. LIU ◽  
...  
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Dielectric Property ◽  
Sol Gel ◽  
Composite Thin Films ◽  
Gel Method ◽  
Sol Gel Method ◽  
Si Substrates ◽  
The Matrix ◽  
Large Dielectric Loss

The dielectric property of ZnFe2O4 – SiO2 composite thin films deposited on Pt - Ti -SiO2- Si substrates, prepared by sol-gel method, are investigated. It is observed that the thin films consist of ZnFe2O4 nanoparticles embedded in the matrix of SiO2. Such a composite structure exhibits a significantly enhanced dielectric constant with respect to SiO2 thin films without too large dielectric loss enhancement.

THICKNESS-DEPENDENT MICROSTRUCTURES AND ELECTRICAL PROPERTIES OF LiTaO3 THIN FILMS PREPARED BY A Sol-Gel PROCESS

2007 ◽  
Vol 21 (18n19) ◽  
pp. 3404-3411
Author(s):  
M. C. KAO ◽  
H. Z. CHEN ◽  
S. L. YOUNG ◽  
C. C. LIN ◽  
C. C. YU
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Grain Size ◽  
Remanent Polarization ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Relative Dielectric Constant ◽  
Coating Technology ◽  
Si Substrates ◽  
Sol Gel Process

LiTaO 3 thin films were deposited on Pt / Ti / SiO 2/ Si substrates by means of a sol-gel spin-coating technology and rapid thermal annealing (RTA). The influence of various annealing treatments on the characteristics of the thin films were studied by varying the single-annealed-layer thickness (50 ~ 200 nm ) and heating temperatures (500 ~ 800° C ) of the samples. Experimental results reveal that the single-annealed-layer strongly influences grain size, dielectricity and ferroelectricity of LiTaO 3 thin films. The grain size of LiTaO 3 thin film decreases slightly with increasing thickness of the single-annealed-layer, and highly c-axis orientated LiTaO 3 films can be obtained for a single-annealed-layer of 50 nm. When the thickness of the single-annealed-layer was increased from 50 to 200 nm, the relative dielectric constant of LiTaO 3 thin film decreased from 65 to 35, but the dielectric loss factor (tanδ) was increased. The LiTaO 3 films with the single-annealed-layer of 50 nm showed excellent ferroelectric properties in terms of a remanent polarization ( P r) of 12.3 μ C /cm2 (Ec ∼ 60 kV/cm), and a low current density of 5.2×l0-8 A /cm2 at 20 kV/cm.

Influence of Strontium Concentration on the Microstructure and Electrical Properties of Sol-Gel Derived Barium Strontium Titanate Thin Films

1996 ◽  
Vol 433 ◽  
Author(s):  
M.C. Gust ◽  
L.A. Momoda ◽  
M.L. Mecartney
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Grain Size ◽  
Barium Strontium Titanate ◽  
Sol Gel ◽  
Heat Treating ◽  
Si Substrates ◽  
Barium Strontium ◽  
Average Grain Size ◽  
Alkoxide Precursors

AbstractBaxSrl−xTiO3 thin films with varying Sr concentration were prepared on Pt coated Si substrates using methoxypropoxide based alkoxide precursors. Films were crystallized by heat treating at 700°C for 30 minutes in an oxygen atmosphere after deposition of each layer. Film thickness ranged from 230 to 260 nm. No evidence of tetragonality was observed in any of the compositions. Films with higher Sr concentrations had a larger average grain size, larger grain size distribution, and increased (111) orientation on (111) oriented Pt. The highest dielectric constant of ˜400 was found for Ba 0.5Sr0.5TiO3, although no direct correlation could be made between the composition and dielectric properties.

Bi Effect on the Microstructure and Dielectric Properties of SrTiO3 Thin Films

2006 ◽  
Vol 514-516 ◽  
pp. 245-249 ◽  
Author(s):  
Olena Okhay ◽  
Vitor M.X. Bergano ◽  
Ai Ying Wu ◽  
Paula M. Vilarinho
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Grain Size ◽  
Low Temperatures ◽  
Room Temperature ◽  
Sol Gel ◽  
Lattice Parameter ◽  
Dielectric Anomaly ◽  
Second Phase ◽  
Si Substrates

Crystalline (Sr1-1.5xBix)TiO3 (SBiT) thin films (0.002 ≤ x ≤ 0.5) were prepared by sol-gel on Pt/TiO2/SiO2/Si substrates. Cubic monophasic SBiT films were obtained for samples with x ≤ 0.167. For films with x ≥ 0.267 a second phase identified as Bi4Ti3O12 was observed. The lattice parameter of SBiT films increases with increasing Bi content, similar to the variation observed in SBiT ceramics. No obviously variation of the grain size with the Bi content was observed. The dielectric constant ε´ at room temperature increases with increasing of Bi concentrations up to x ≤ 0.1. The loss tangent of Bi doped SrTiO3 films is approximately 0.05 and lower than undoped ST films at 10kHz. The higher values of ε´ of Bi doped ST films with x=0.1 and x=0.167 in comparison with undoped films may suppose the appearance of a dielectric anomaly at low temperatures, which will be dependent on the Bi content.

Rapid thermal processing of lead zirconate titanate thin films on Pt–GaAs substrates based on a novel 1,1,1-tris(hydroxymethyl)ethane sol-gel route

1999 ◽  
Vol 14 (2) ◽  
pp. 494-499 ◽  
Author(s):  
S. Arscott ◽  
R. E. Miles ◽  
J. D. Kennedy ◽  
S. J. Milne
Keyword(s):  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Thermal Processing ◽  
Sol Gel ◽  
Rapid Thermal Processing ◽  
Low Frequency ◽  
Lead Zirconate ◽  
Si Substrates ◽  
Pzt Film ◽  
Gaas Substrates

0.53Ti0.47)O3 have been prepared on platinized GaAs (Pt–GaAs) substrates using a new 1,1,1-tris(hydroxymethyl)ethane (THOME) based sol-gel technique. Rapid thermal processing (RTP) techniques were used to decompose the sol-gel layer to PZT in an effort to avoid problems of GayAs outdiffusion into the PZT. A crystalline PZT film was produced by firing the sol-gel coatings at 600 or 650 ° for a dwell time of 1 s using RTP. A single deposition of the precursor sol resulted in a 0.4 μm thick PZT film. X-ray diffraction measurements revealed that the films possessed a high degree of (111) preferred orientation. Measured average values of remanent polarization (Pr ) and coercive field (Ec) for the film annealed at 650 ° for 1 s were 24 μC/cm2 and 32 kV/cm, respectively, together with a low frequency dielectric constant and loss tangent at 1 kHz of 950 and 0.02. These values are comparable to those obtainable on platinized silicon (Pt–Si) substrates using conventional sol-gel methods, and are an improvement on PZT thin films prepared on platinized GaAs using an earlier sol-gel route based on 1,3-propanediol.

scholarly journals Electrostatic coupling driven dielectric enhancement of PZT/BTO multilayer thin films

2021 ◽  
Author(s):  
Huang Zhong ◽  
Xin Wang ◽  
Xin Hong Li ◽  
Zhen Ya Lu ◽  
Zhi Wu Chen
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Sol Gel ◽  
Internal Field ◽  
Multilayer Thin Films ◽  
X Ray Diffraction ◽  
Si Substrates ◽  
Sol Gel Process ◽  
Dielectric Enhancement ◽  
Electrostatic Coupling

Abstract In this study, PbZr0.52Ti0.48O3/BaTiO3 (PZT/BTO) multilayers with varying layer fractions were deposited on Pt/Ti/SiO2/Si substrates by sol-gel process. The films were characterized by X-ray diffraction and scanning electron microscopy (SEM). The result shows that there exists a dielectric enhancement when the BTO layer fraction x is around 0.5, and at this fraction, the dielectric constant of PZT/BTO is 590 at 100 kHz, which is far more than that of monolithic PZT or BTO films (478 and 284, respectively). The thermodynamic analysis shows that the measured dielectric constant is close to the simulation values when x closes to 0.5, otherwise it better consists with the series connection calculation values. The result indicates that the internal field resulting from the polarization mismatch between two ferroelectric layers contributes to the enhancement of PZT/BTO heterogeneous thin films.

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