Relative dielectric constant of epitaxial BaTiO3 thin films in the GHz frequency range

2003 ◽  
Vol 83 (25) ◽  
pp. 5274-5276 ◽  
Author(s):  
T. Hamano ◽  
D. J. Towner ◽  
B. W. Wessels
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Relative Dielectric Constant ◽  
Frequency Range

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.

TRANSPORT PROPERTIES OF THERMALLY EVAPORATED In2Se3 THIN FILMS

2009 ◽  
Vol 16 (05) ◽  
pp. 723-729 ◽  
Author(s):  
D. NITHYAPRAKASH ◽  
B. PUNITHAVENI ◽  
J. CHANDRASEKARAN
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Ac Conductivity ◽  
Thermal Evaporation ◽  
Frequency Range ◽  
X Ray Diffraction ◽  
Cbh Model ◽  
X Ray ◽  
Correlated Barrier Hopping ◽  
Tan Δ

Thin films of In2Se3 were prepared by thermal evaporation. X-ray diffraction indicated that the as-grown films were amorphous in nature and became polycrystalline γ-In2Se3 films after annealing. The ac conductivity and dielectric properties of In2Se3 films have been investigated in the frequency range 100 Hz–100 kHz. The ac conductivity σ ac is found to be proportional to ωn where n < 1. The temperature dependence of both ac conductivity and the parameter n is reasonably well interpreted by the correlated barrier hopping (CBH) model. The values of dielectric constant ε and loss tangent tan δ were found to increase with frequency and temperature. The ac conductivity of the films was found to be hopping mechanism. In I–V characteristic for different field and temperature were studied and it has been found that the conduction process is Poole–Frenkel type.

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.

Time-domain Terahertz Spectroscopy of Strontium Bismuth Tantalate Thin Films

2003 ◽  
Vol 784 ◽  
Author(s):  
K. Kotani ◽  
M. Misra ◽  
I. Kawayama ◽  
M. Tonouchi
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Time Domain ◽  
Terahertz Spectroscopy ◽  
Ferroelectric Material ◽  
Frequency Region ◽  
Frequency Range ◽  
The Difference ◽  
Dielectric And Optical Properties ◽  
Mgo Substrate

ABSTRACTWe have measured the dielectric and optical properties of pulsed laser deposited SrBi2Ta 2O9 and Sr0.8Bi2.2Ta2O9 thin films on MgO substrate in THz frequency region by THz time-domain spectroscopy. The imaginary parts of the dielectric constant of both the samples show broad peaks in the frequency range 0.5–1.0 THz, which may be due to the soft mode in SBT in this frequency spectrum. The difference in the real part of the dielectric constant of Sr0.8Bi2.2Ta2O9 thin films is small for MHz and THz frequencies. On the other hand, the value of real part of dielectric constant of SrBi2Ta2O9 thin films in THz frequency range is much smaller than that in MHz frequency region, indicating that SrBi2Ta2O9 is not simply displacive ferroelectric material.

scholarly journals Application of Amorphous Zirconium-Yttrium-Aluminum-Magnesium-Oxide Thin Film with a High Relative Dielectric Constant Prepared by Spin-Coating

Membranes ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 608
Author(s):  
Huiyun Yang ◽  
Zhihao Liang ◽  
Xiao Fu ◽  
Zhuohui Xu ◽  
Honglong Ning ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Dielectric Constant ◽  
Magnesium Oxide ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
Relative Dielectric Constant ◽  
Oxide Thin Film ◽  
Yttrium Aluminum

Amorphous metal oxide has been a popular choice for thin film material in recent years due to its high uniformity. The dielectric layer is one of the core materials of the thin film transistor (TFT), and it affects the ability of charges storage in TFT. There is a conflict between a high relative dielectric constant and a wide band gap, so we solved this problem by using multiple metals to increase the entropy of the system. In this paper, we prepared zirconium-yttrium-aluminum-magnesium-oxide (ZYAMO) dielectric layers with a high relative dielectric constant using the solution method. The basic properties of ZYAMO films were measured by an atomic force microscope (AFM), an ultraviolet-visible spectrophotometer (UV-VIS), etc. It was observed that ZYAMO thin films had a larger optical band when the annealing temperature increased. Then, metal-insulator-metal (MIM) devices were fabricated to measure the electrical properties. We found that the leakage current density of the device is relatively lower and the ZYAMO thin film had a higher relative dielectric constant as the concentration went up. Finally, it reached a high relative dielectric constant of 56.09, while the leakage current density was no higher than 1.63 × 10−6 A/cm2@ 0.5 MV/cm at 1.0 M and 400 °C. Therefore, the amorphous ZYAMO thin films has a great application in the field of high permittivity request devices in the future.

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.

Dielectric and structural properties of iron- and sodium-fumarates

2012 ◽  
Vol 36 (1) ◽  
pp. 21-29 ◽  
Author(s):  
Sonja Skuban ◽  
Tanja Džomié ◽  
Agneš Kapor ◽  
Željka Cvejić ◽  
Srđan Rakic
Keyword(s):  
Dielectric Constant ◽  
Ionic Conductivity ◽  
Structural Properties ◽  
Ac Conductivity ◽  
Loss Factor ◽  
Low Frequency ◽  
Relative Dielectric Constant ◽  
Frequency Range ◽  
Dielectric Parameters ◽  
Increasing Temperature

Abstract The behaviour of dielectric parameters such as the relative dielectric constant (ε''), the relative loss factor (ε'') and the ac conductivity of well known pharmaceutical materials Fe(II)-fumarate and Na-fumarate were studied as a function of temperature (in the range from 303K to 483 K) and frequency (in the range from 0.1 Hz to 100 kHz). The values of the conductivity are in the range of 10−5 Ω−1m−1 to 10−9 Ω−1m−1 for Fe(II)-fumarate and 10−6 Ω−1m−1 to 10−11 Ω−1m−1 for Na-fumarate. The conductivity of both materials increases with the increase in temperature and frequency. It was found that both ε' and ε'' decrease with increasing frequency and increase with increasing temperature for both materials. The highest changes are in the low frequency range. The obtained values of the dielectric parameters and conductivity suggest that these materials are dielectric with similar structure, most probably polymeric, with the mechanism of ionic conductivity.

scholarly journals Low-temperature preparation of BaTiO3 thin films by intense, pulsed, ion beam evaporation

1996 ◽  
Vol 14 (4) ◽  
pp. 537-542 ◽  
Author(s):  
T. Sonegawa ◽  
C. Grigoriu ◽  
K. Masugata ◽  
K. Yatsui ◽  
Y. Shimotori ◽  
...  
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Barium Titanate ◽  
Low Temperature ◽  
Substrate Temperature ◽  
Ion Beam ◽  
Frequency Range ◽  
Low Temperature Preparation ◽  
Temperature Preparation

Cubic barium titanate (BaTiO3) thin films have been prepared in situ, on a low-temperature substrate, Al/SiO2/Si(100), by intense, pulsed ion beam evaporation. We have first proposed a new deposition configuration, backside deposition, which, in comparison with standard frontside deposition, produces very smooth thin films, Rα (mean roughness) ≈ 3 ∼ 9 nm, without any droplets. There is no significant change of the dielectric constant in the frequency range of 10 ∼ 105 Hz. The dielectric constant for the film deposited at the substrate temperature of 200˚C is typically ∼90 at 1 kHz.

scholarly journals Identification of the complex relative dielectric constant of porous polymers at different degrees of humidity

2008 ◽  
Vol 6 ◽  
pp. 5-8 ◽  
Author(s):  
K. Haake ◽  
J. L. ter Haseborg
Keyword(s):  
Dielectric Constant ◽  
Cylindrical Shell ◽  
Relative Dielectric Constant ◽  
Porous Polymers ◽  
Scattering Parameters ◽  
Frequency Range ◽  
Climate Chamber ◽  
Temperature And Humidity ◽  
Climate Interactions ◽  
Rf Measurements

Abstract. In order to investigate the complex relative dielectric constant of different materials over a frequency range of 50 MHz to 3 GHz a setup has been built that allows rf-measurements in a climate chamber. Within this chamber the temperature and humidity can be changed and be measured by accurate sensors. The construction of the rf-part of the setup has been made with an outer cylindrical shell that allows climate interactions through its large orifices. Methods for calculating the complex relative dielectric constant from the measured scattering parameters are presented and the changes of the relative constants due to different humidity conditions are shown.

Microstructural and Electrical Characterization of Barium Strontium Titanatebased Solid Solution Thin Films Deposited on Ceramic Substrates by Pulsed Laser Deposition

2002 ◽  
Vol 720 ◽  
Author(s):  
Costas G. Fountzoulas ◽  
Daniel M. Potrepka ◽  
Steven C. Tidrow
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Electrical Characterization ◽  
Field Variable ◽  
Laser Deposition ◽  
X Ray Diffraction ◽  
Ceramic Substrates ◽  
Nominal Thickness

AbstractFerroelectrics are multicomponent materials with a wealth of interesting and useful properties, such as piezoelectricity. The dielectric constant of the BSTO ferroelectrics can be changed by applying an electric field. Variable dielectric constant results in a change in phase velocity in the device allowing it to be tuned in real time for a particular application. The microstructure of the film influences the electronic properties which in turn influences the performance of the film. Ba0.6Sr0.4Ti1-y(A 3+, B5+)yO3 thin films, of nominal thickness of 0.65 μm, were synthesized initially at substrate temperatures of 400°C, and subsequently annealed to 750°C, on LaAlO3 (100) substrates, previously coated with LaSrCoO conductive buffer layer, using the pulsed laser deposition technique. The microstructural and physical characteristics of the postannealed thin films have been studied using x-ray diffraction, scanning electron microscopy, and nano indentation and are reported. Results of capacitance measurements are used to obtain dielectric constant and tunability in the paraelectric (T>Tc) regime.

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