scholarly journals Structure and Electrical Properties of Na0.5Bi0.5TiO3 Epitaxial Films with (110) Orientation

Crystals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 558 ◽  
Author(s):  
Jianmin Song ◽  
Jie Gao ◽  
Suwei Zhang ◽  
Laihui Luo ◽  
Xiuhong Dai ◽  
...  
Keyword(s):  
Leakage Current ◽  
Ultraviolet Light ◽  
Leakage Current Density ◽  
Electric Fields ◽  
Current Density ◽  
Ferroelectric Properties ◽  
Srtio3 Substrate ◽  
Conduction Behavior ◽  
Effective Polarization ◽  
Ferroelectric Capacitors

Pt/Na0.5Bi0.5TiO3/La0.5Sr0.5CoO3 (Pt/NBT/LSCO) ferroelectric capacitors were fabricated on (110) SrTiO3 substrate. Both NBT and LSCO films were epitaxially grown on the (110) SrTiO3 substrate. It was found that the leakage current density of the Pt/NBT/LSCO capacitor is favorable to ohmic conduction behavior when the applied electric fields are lower than 60 kV/cm, and bulk-limited space charge-limited conduction takes place when the applied electric fields are higher than 60 kV/cm. The Pt/NBT/LSCO capacitor possesses good fatigue resistance and retention, as well as ferroelectric properties with Pr = 35 μC/cm2. The ferroelectric properties of the Pt/NBT/LSCO capacitor can be modulated by ultraviolet light. The effective polarization, ΔP, was reduced and the maximum polarization Pmax was increased for the Pt/NBT/LSCO capacitor when under ultraviolet light, which can be attributed to the increased leakage current density and non-reversible polarization P^ caused by the photo-generated carriers.

Effect of few-layer graphene films as electrodes on the electrical properties of ferroelectric capacitors

RSC Advances ◽  
2016 ◽  
Vol 6 (70) ◽  
pp. 66011-66017
Author(s):  
Hong Jing Han ◽  
Yan Na Chen ◽  
Zhan Jie Wang
Keyword(s):  
Electrical Properties ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
Van Der Waals ◽  
Layer Graphene ◽  
Graphene Films ◽  
Few Layer Graphene ◽  
Ferroelectric Capacitors

An FLG/PZT/Pt capacitor exhibits comparable polarization compared with a Pt/PZT/Pt capacitor but the magnitude of leakage current density for the FLG/PZT/Pt capacitor is largely decreased due to the van der Waals gap at the FLG/PZT interface.

Leakage Current Behavior in CaZrO3 Thin Films for High-k Applications

2004 ◽  
Vol 811 ◽  
Author(s):  
Ting Yu ◽  
Weiguang Zhu ◽  
Xiaofeng Chen ◽  
Yuekang Lu
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Electrical Properties ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Electric Fields ◽  
Current Density ◽  
Breakdown Strength ◽  
Sol Gel ◽  
High K

ABSTRACTElectrical properties and leakage current mechanisms of perovskite CaZrO3 dielectric thin films have been studied in this paper. CaZrO3 thin films were deposited on Pt/SiO2/n-Si substrate by the sol-gel wet chemical technology, and then annealed at temperatures ranging from 550 to 700 °C for 1h in O2. The films with platinum (Pt) top and bottom electrodes were characterized with respect to the leakage current as a function of temperature and applied voltage. The CaZrO3 film annealed at 600 °C was amorphous and showed good electrical properties with a dielectric constant of about 15 and leakage current density of 10−8 A/cm2 at high applied electrical field of 2.5 MV/cm. The data can be interpreted via a Schottky barrier model. The conduction mechanism at low electric fields is due to Ohmic conduction. On the other hand Schottky mechanism dominates at the intermediate fields. The high dielectric constant, low leakage current density and high breakdown strength suggest that the CaZrO3 thin film is a promising candidate for high-k applications.

Bismuth composition control of SrBi2TaNbO9 thin films by heat treating Bi2O3-inserted heterostructure

1999 ◽  
Vol 14 (7) ◽  
pp. 2986-2992 ◽  
Author(s):  
Yoon-Baek Park ◽  
Jeon-Kook Lee ◽  
Hyung-Jin Jung ◽  
Jong-Wan Park
Keyword(s):  
Thin Films ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
Ferroelectric Properties ◽  
Stoichiometric Composition ◽  
Heat Treating ◽  
The Other ◽  
Composition Control ◽  
Other Hand

Ferroelectric properties of SrBi2TaNbO9 (SBTN) thin films were changed by the amount of Bi content in SBTN. We proposed that the addition of excess Bi to the SBTN thin films could be accomplished by heat treating the SBTN/Bi2O3/SBTN heterostructure fabricated by the radio frequency magnetron sputtering method. The Bi composition was controlled by changing the thickness of the inserted Bi2O3 from 50 to 400Å in the SBTN/Bi2O3/SBTN heterostructure. As the thickness of Bi2O3 films was increased from 0 to 100 Å, the grain grew faster and the ferroelectric properties improved. On the other hand, when the thickness, of Bi2O3 films was thicker than 150 Å, the ferroelectric properties deteriorated. In particular, when a 400 Å Bi2O3 layer was inserted between SBTN films, a Bi2Pt phase appeared and the Bi2O3 films remained between SBTN films, resulting in poor ferroelectric properties. A Bi2Pt phase was formed by the reaction between the platinum bottom electrode and Bi2O3 films. On the other hand, the leakage current density of SBTN thin films decreased with the increase of inserted Bi2O3 film thickness. As the thickness of inserted Bi2O3 films was increased from 0 to 50 Å, leakage current density abruptly decreased because Bi content of the SBTN thin films was increased from 8 mol% deficient to stoichiometric composition. As the thickness of inserted Bi2O3 films increased from 100 to 400 Å, leakage current density gradually decreased because the remaining Bi2O3 layer in SBTN thin films increased.

Effects of Film Thickness on Microstructure and Ferroelectric Properties of Bi3.15Nd0.85Ti3O12 Thin Films Prepared by Sol-Gel Method

2011 ◽  
Vol 239-242 ◽  
pp. 1275-1278
Author(s):  
Chang Yong Liu ◽  
Dong Yun Guo ◽  
Chuan Bin Wang ◽  
Qiang Shen ◽  
Lian Meng Zhang
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Layered Perovskite ◽  
Gel Method ◽  
Sol Gel Method

Bi3.15Nd0.85Ti3O12 (BNT) thin films with different thicknesses (200, 270, 360, 450 and 540 nm) were prepared on Pt/Ti/SiO2/Si substrates by sol–gel method. The effect of film thickness on the microstructure and ferroelectric properties of BNT thin films was investigated. All BNT thin films were consisted of a single phase of bismuth-layered perovskite structure. With increasing film thickness, grains gradually became larger, the remanent polarization (2Pr) firstly increased and then decreased, and the leakage current density showed opposite trend. The 360 nm-thick BNT film exhibited better electrical properties with 2Pr26 µC/cm2, coercive field (2Ec) 220 kV/cm, dielectric constant 345 (at 1 MHz) and low leakage current density.

Low Temperature Preparation of High-Quality Pb(Zr,Ti)O3 Films by Metal Organic Chemical Vapor Deposition with High Reproducibility

2001 ◽  
Vol 688 ◽  
Author(s):  
Hiroshi Funakubo ◽  
Kuniharu Nagashima ◽  
Masanori Aratani ◽  
Kouji Tokita ◽  
Takahiro Oikawa ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
Vapor Deposition ◽  
Deposition Temperature ◽  
Chemical Vapor ◽  
Process Window ◽  
High Quality ◽  
Low Temperature Preparation

AbstractPb(Zr,Ti)O3 (PZT) is one of the most promising materials for ferroelectric random access memory (FeRAM) application. Among the various preparation methods, metalorganic chemical vapor deposition (MOCVD) has been recognized as a most important one to realize high density FeRAM because of its potential of high-step-coverage and large-area-uniformity of the film quality.In the present study, pulsed-MOCVD was developed in which a mixture of the source gases was pulsed introduced into reaction chamber with interval. By using this deposition technique, simultaneous improvements of the crystallinity, surface smoothness, and electrical property of the film have been reached by comparing to the conventional continuous gas-supplied MOCVD. Moreover, this film had larger remanent polarization (Pr) and lower leakage current density. This is owing to reevaporation of excess Pb element from the film and increase of migration on the surface of substrate during the interval time.This process is also very effective to decrease the deposition temperature of the film having high quality. In fact, the Pr and the leakage current density of polycrystalline Pb(Zr0.35Ti0.65)O3 film deposited at 415 °C were 41.4 μC/cm2 and on the order of 10−7 A/cm2 at 200 kV/cm. This Pr value was almost the same as that of the epitaxially grown film deposited at 415 °C with the same composition corrected for the orientation difference. This suggests that the polycrystalline PZT film prepared by pulsed-MOCVD had the epitaxial-grade ferroelectric properties even through the deposition temperature was as low as 415 °C. Moreover, large “process window” comparable to the process window at 580 °C, above 150 °C higher temperature and was widely used condition, was achieved even at 395°C by the optimization of the deposition condition.

3 kV Normally-Off 4H-SiC Buried Gate Static Induction Transistors (SiC-BGSITs)

2014 ◽  
Vol 778-780 ◽  
pp. 899-902 ◽  
Author(s):  
Akio Takatsuka ◽  
Yasunori Tanaka ◽  
Koji Yano ◽  
Norio Matsumoto ◽  
Tsutomu Yatsuo ◽  
...  
Keyword(s):  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
Threshold Voltage ◽  
Room Temperature ◽  
Fabrication Process ◽  
Drain Voltage ◽  
Static Induction Transistors ◽  
Static Induction

3 kV normally-off SiC-buried gate static induction transistors (SiC-BGSITs) were fabricated by using an innovative fabrication process that was used by us previously to fabricate 0.7–1.2 kV SiC-BGSITs. The fabricated device shows the lowest specific on-resistance of 9.16 mΩ·cm2, compared to all other devices of the same class. The threshold voltage of this device was 1.4 V at room temperature and was maintained at values more than 1 V with normally-off characteristics at 200 °C. The device can block drain voltage of 3 kV with a leakage current density of 6.9 mA/cm2.

Growth of Epitaxial Site-Engineered Bi4Ti3O12-Basded Thin Films by Mocvdand Their Characterization

2002 ◽  
Vol 748 ◽  
Author(s):  
Hiroshi Funakubo ◽  
Tomohiro Sakai ◽  
Takayuki Watanabe ◽  
Minoru Osada ◽  
Masato Kakihana ◽  
...  
Keyword(s):  
Thin Films ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
Spontaneous Polarization ◽  
Chemical Vapor ◽  
The Other ◽  
Other Hand ◽  
La Substitution ◽  
Lower Temperature

ABSTRACTThin films of BIT, La-substituted BIT (BLT) and La- and V-cosubstituted BIT(BLTV) were epitaxially grown on SrRuO3//SrTiO3 substrates at 850°C by metalorganic chemical vapor deposition (MOCVD), and their electrical properties were systematically compared. All films on (100), (110) and (111)-oriented substrates were epitaxially grown with (001)-, (104)-/(014)-and (118) –preferred orientations, respectively. The leakage current density of the BLTV film was almost the same with that of the BLT film, but was smaller than that of BIT film, suggesting that the La substitution contributed to the decrease of the leakage current density especially in pseudoperovskite layer. Spontaneous polarization of the BLTV film was estimated to be almost the same with the BLT film but was smaller that that of the BIT film. This is explained by the decrease of Tc with the La substitution, while V did not contribute to the change of the Curie temperature (Tc ). On the other hand, the coercive field (Ec) value of the BLTV was smaller than that of the BIT and the BLT films. As a result, La substitution contributed to the decrease of the leakage current density together with the decrease of the spontaneous polarization due to the decrease of the Tc. On the other hand, V substitution contributes to the decrease of the defects that suppress the domain motion and increases the Ec value. Therefore, each substitution of La and V plays different roles and this contribution is remarkable for the films deposited at lower temperature.

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