Effects of Fe and Al co-doping on the leakage current density and clamp voltage ratio of ZnO varistor

2018 ◽  
Vol 747 ◽  
pp. 1018-1026 ◽  
Author(s):  
Jinlou Shen ◽  
Yujing Zhang ◽  
Mingyu Li ◽  
Runxi Bao ◽  
Meng Shen ◽  
...  
Keyword(s):  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
Co Doping ◽  
Zno Varistor ◽  
Voltage Ratio

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.

scholarly journals Structural and Electrical Characteristics of Metal-Ferroelectric Pb1.1(Zr0.40Ti0.60)O3-Insulator (ZnO)-Silicon Capacitors for Nonvolatile Applications

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
S. R. Krishnamoorthi ◽  
K. S. Venkatesh ◽  
Rajangam Ilangovan
Keyword(s):  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
Sol Gel ◽  
Film Surface ◽  
Memory Window ◽  
Mis Structure ◽  
Insulator Layer ◽  
Window Width ◽  
Ferroelectric Layer

In this work metal-ferroelectric-insulator-semiconductor (MFIS) thin-film structures usingPb1.1Zr0.40Ti0.60O3(PZT) as the ferroelectric layer and zinc oxide (ZnO) as the insulator layer were fabricated on n-type (100) Si substrate.Pb1.1Zr0.40Ti0.60O3and ZnO thin films were prepared on Si by the sol-gel route and thermal deposition method, respectively. On the optimized PZT (140 nm) and ZnO (40 nm) films were examined by scanning electron microscope (SEM). From AFM data the root mean square (r.m.s.) roughness of the film surface is 13.11 nm. The leakage current density of ZnO/n-Si (MIS) structure was as low as 1.8 × 10−8A/cm2at 2.5 V. The capacitance versus voltage (C-V) characteristics of the annealed ZnO/Si (MIS) diode indicated the good interface properties and no hysteresis was observed. Au/PZT (140 nm)/ZnO (40 nm)/Si (100) leakage-current density was about 5.7 × 10−8 A/cm2at positive bias voltage of 3 V. The large memory window width in C-V (capacitance-voltage) curve of Au/PZT/ZnO/Si capacitor was about 2.9 V under ±12 V which thus possibly enables nonvolatile applications. The memory window as a function of temperature was also discussed.

Preparation and Characterization Of SrTio3 Thin Films Using ECR Plasma Assisted MOCVD

1995 ◽  
Vol 415 ◽  
Author(s):  
Joon Sung Lee ◽  
Han Wook Song ◽  
Dae Sung Yoon ◽  
Byung Hyuk Jun ◽  
Byoung Gon Yu ◽  
...  
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
Oxygen Plasma ◽  
Grain Structure ◽  
Breakdown Field ◽  
Ecr Plasma ◽  
Step Coverage

ABSTRACTSrTiO3 thin films were prepared on Si(p-type 100) and Pt/SiO2/Si substrates using ECR plasma (or without ECR plasma) assisted MOCVD. Sr(TMI-D)2 and Ti-isopropoxide were used as Sr and Ti metal organic sources, respectively. Perovskite SrTiO3 films were obtained at relatively low temperature of 500°C (using ECR oxygen plasma. Experimental results indicated that higher deposition temperature and ECR oxygen plasma increase the crystallinity, the dielectric constant and the leakage current density. The dielectric constant and the dielectric loss were 222 and 0.04, respectively, for 1234 Å thin SrTiO3 film (Sr/(Sr+Ti)=0.5). The leakage current density was 3.78 × 10−7 A/cm2 at 1.0V, and the dielectric breakdown field was 0.57MV/cm. SEM analyses showed that SrTiO3 films have a uniform and fine grain structure. In terms of step coverage, a lateral step coverage of 50% at 0.8 μm step (the aspect ratio was 1) was obtained with the thickness uniformity of ± 0.5% and the composition uniformity of ±1.2% at 4′′ wafer.

Effects of Very High Neutron Fluence Irradiation on p+n Junction 4H-SiC Diodes

2007 ◽  
Vol 556-557 ◽  
pp. 917-920 ◽  
Author(s):  
Francesco Moscatelli ◽  
Andrea Scorzoni ◽  
Antonella Poggi ◽  
Mara Passini ◽  
Giulio Pizzocchero ◽  
...  
Keyword(s):  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
Reverse Bias ◽  
Neutron Fluence ◽  
Signal To Noise Ratio ◽  
Reverse Current ◽  
Low Noise ◽  
High Signal ◽  
Very High

In this work we analyzed the radiation hardness of SiC p+n diodes after very high 1 MeV neutron fluence. The diode structure is based on a p+ emitter ion implanted in n-type epilayer with thickness equal to 5 %m and donor doping ND = 3×1015 cm-3. Before irradiation, the average leakage current density at 100 V reverse bias was of the order of 3 nA/cm2. These devices were irradiated at four different fluence values, logarithmically distributed in the range 1014-1016 (1 MeV) neutrons/cm2. After irradiation the epilayer material became more resistive, as indicated by the reduction of the forward and reverse current density at a given voltage. In particular, after a neutron fluence of 1×1014 n/cm2 the epilayer active doping concentration decreased to 1.5×1015 cm-3. After irradiation at 1016 n/cm2, i.e. the highest fluence value, the average leakage current density at 100 V reverse bias decreased to values of the order of 0.1 nA/cm2. This very low noise even after very high fluence is very important to obtain a high signal to noise ratio even at room temperature.

Structure, ferroelectric/magnetoelectric properties and leakage current density of (Bi0.85Nd0.15)FeO3 thin films

2011 ◽  
Vol 509 (17) ◽  
pp. 5326-5335 ◽  
Author(s):  
A.Z. Simões ◽  
L.S. Cavalcante ◽  
F. Moura ◽  
E. Longo ◽  
J.A. Varela
Keyword(s):  
Thin Films ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
Magnetoelectric Properties
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