scholarly journals Volt-ampere characteristic of the double Schottky barrier

2021 ◽  
Vol 29 (1) ◽  
pp. 91-98
Author(s):  
A. I. Ivon
Keyword(s):  
Zinc Oxide ◽  
Schottky Barrier ◽  
Electron Emission ◽  
Impact Ionization ◽  
Contact Region ◽  
Schottky Diodes ◽  
Absolute Temperature ◽  
Electrical Circuit ◽  
Boltzmann Constant ◽  
Electron Charge

The volt-ampere characteristic (I-V characteristic) of the double Schottky barrier located in the contact region of ZnO grains of zinc oxide based varistor ceramics is calculated using the mechanism of the above-barrier electron emission. I-V characteristic is symmetric to the polarity of the voltage U. At U > 2kBT/e (kB is the Boltzmann constant, T is the absolute temperature, e is electron charge) the electric current is saturated. The contact of ZnO grains with a double Schottky barrier behaves like an electrical circuit consisting of two oppositely connected Schottky diodes. A small maximum possible decrease in the height of the double Schottky barrier in an electric field ~ 0.7kBT ≈ 0.018 eV does not allow explaining the high nonlinearity of I – V characteristic of varistor materials by the above-barrier electron emission. The most probable cause of nonlinearity is the tunnel emission of electrons and impact ionization.

scholarly journals A Study about Schottky Barrier Height and Ideality Factor in Thin Film Transistors with Metal/Zinc Oxide Nanoparticles Structures Aiming Flexible Electronics Application

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1188
Author(s):  
Ivan Rodrigo Kaufmann ◽  
Onur Zerey ◽  
Thorsten Meyers ◽  
Julia Reker ◽  
Fábio Vidor ◽  
...  
Keyword(s):  
Thin Film ◽  
Zinc Oxide ◽  
Schottky Barrier ◽  
Barrier Height ◽  
Flexible Electronics ◽  
Thin Film Transistors ◽  
Zinc Oxide Nanoparticles ◽  
Schottky Barrier Height ◽  
Oxide Nanoparticles ◽  
Semiconductor Interfaces

Zinc oxide nanoparticles (ZnO NP) used for the channel region in inverted coplanar setup in Thin Film Transistors (TFT) were the focus of this study. The regions between the source electrode and the ZnO NP and the drain electrode were under investigation as they produce a Schottky barrier in metal-semiconductor interfaces. A more general Thermionic emission theory must be evaluated: one that considers both metal/semiconductor interfaces (MSM structures). Aluminum, gold, and nickel were used as metallization layers for source and drain electrodes. An organic-inorganic nanocomposite was used as a gate dielectric. The TFTs transfer and output characteristics curves were extracted, and a numerical computational program was used for fitting the data; hence information about Schottky Barrier Height (SBH) and ideality factors for each TFT could be estimated. The nickel metallization appears with the lowest SBH among the metals investigated. For this metal and for higher drain-to-source voltages, the SBH tended to converge to some value around 0.3 eV. The developed fitting method showed good fitting accuracy even when the metallization produced different SBH in each metal-semiconductor interface, as was the case for gold metallization. The Schottky effect is also present and was studied when the drain-to-source voltages and/or the gate voltage were increased.

scholarly journals 60–700 K CTAT and PTAT Temperature Sensors with 4H-SiC Schottky Diodes

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 942
Author(s):  
Razvan Pascu ◽  
Gheorghe Pristavu ◽  
Gheorghe Brezeanu ◽  
Florin Draghici ◽  
Philippe Godignon ◽  
...  
Keyword(s):  
Low Cost ◽  
Schottky Diodes ◽  
Schottky Contact ◽  
High Sensitivity ◽  
Xrd Analysis ◽  
Absolute Temperature ◽  
Lower Sensitivity ◽  
Readout Circuit ◽  
Sensing Element ◽  
High Performing

A SiC Schottky dual-diode temperature-sensing element, suitable for both complementary variation of VF with absolute temperature (CTAT) and differential proportional to absolute temperature (PTAT) sensors, is demonstrated over 60–700 K, currently the widest range reported. The structure’s layout places the two identical diodes in close, symmetrical proximity. A stable and high-barrier Schottky contact based on Ni, annealed at 750 °C, is used. XRD analysis evinced the even distribution of Ni2Si over the entire Schottky contact area. Forward measurements in the 60–700 K range indicate nearly identical characteristics for the dual-diodes, with only minor inhomogeneity. Our parallel diode (p-diode) model is used to parameterize experimental curves and evaluate sensing performances over this far-reaching domain. High sensitivity, upwards of 2.32 mV/K, is obtained, with satisfactory linearity (R2 reaching 99.80%) for the CTAT sensor, even down to 60 K. The PTAT differential version boasts increased linearity, up to 99.95%. The lower sensitivity is, in this case, compensated by using a high-performing, low-cost readout circuit, leading to a peak 14.91 mV/K, without influencing linearity.

Improvement in Schottky barrier in-homogeneities of Ni/AlGaN/GaN Schottky diodes after cumulative γ-ray irradiation

2021 ◽  
Author(s):  
Ajay Kumar Visvkarma ◽  
Chandan Sharma ◽  
Chanchal Saraswat ◽  
D S Rawal ◽  
Seema Vinayak ◽  
...  
Keyword(s):  
Schottky Barrier ◽  
Schottky Diodes ◽  
Γ Ray

Zinc oxide solution-processed Schottky diodes operating at 5G frequencies

2021 ◽  
Author(s):  
Dimitra G. Georgiadou ◽  
James Semple ◽  
Abhay Sagade ◽  
Thomas Anthopoulos
Keyword(s):  
Zinc Oxide ◽  
Schottky Diodes ◽  
Solution Processed

High Temperature capable SiC Schottky diodes, based on buried grid design.

2014 ◽  
Vol 2014 (HITEC) ◽  
pp. 000058-000060
Author(s):  
Tomas Hjort ◽  
Adolf Schöner ◽  
Andy Zhang ◽  
Mietek Bakowski ◽  
Jang-Kwon Lim ◽  
...  
Keyword(s):  
High Temperature ◽  
Schottky Barrier ◽  
Leakage Current ◽  
Schottky Diode ◽  
Schottky Diodes ◽  
Electrical Characteristics ◽  
Schottky Barrier Diodes ◽  
Grid Design ◽  
High Temperature Operation

Electrical characteristics of 4H-SiC Schottky barrier diodes, based on buried grid design are presented. The diodes, rated to 1200V/10A and assembled into high temperature capable TO254 packages, have been tested and studied up to 250°C. Compared to conventional SiC Schottky diodes, Ascatron's buried grid SiC Schottky diode demonstrates several orders of magnitude reduced leakage current at high temperature operation.

scholarly journals Control of the Boundary between the Gradual and Abrupt Modulation of Resistance in the Schottky Barrier Tunneling-Modulated Amorphous Indium-Gallium-Zinc-Oxide Memristors for Neuromorphic Computing

Electronics ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1087 ◽  
Author(s):  
Jun Tae Jang ◽  
Geumho Ahn ◽  
Sung-Jin Choi ◽  
Dong Myong Kim ◽  
Dae Hwan Kim
Keyword(s):  
Zinc Oxide ◽  
Schottky Barrier ◽  
Oxygen Content ◽  
Bimodal Distribution ◽  
Indium Gallium Zinc Oxide ◽  
Metal Electrodes ◽  
Neuromorphic Computing ◽  
Computing Systems ◽  
Proposed Model ◽  
Indium Gallium

The transport and synaptic characteristics of the two-terminal Au/Ti/ amorphous Indium-Gallium-Zinc-Oxide (a-IGZO)/thin SiO2/p+-Si memristors based on the modulation of the Schottky barrier (SB) between the resistive switching (RS) oxide layer and the metal electrodes are investigated by modulating the oxygen content in the a-IGZO film with the emphasis on the mechanism that determines the boundary of the abrupt/gradual RS. It is found that a bimodal distribution of the effective SB height (ΦB) results from further reducing the top electrode voltage (VTE)-dependent Fermi-level (EF) followed by the generation of ionized oxygen vacancies (VO2+s). Based on the proposed model, the influences of the readout voltage, the oxygen content, the number of consecutive VTE sweeps on ΦB, and the memristor current are explained. In particular, the process of VO2+ generation followed by the ΦB lowering is gradual because increasing the VTE-dependent EF lowering followed by the VO2+ generation is self-limited by increasing the electron concentration-dependent EF heightening. Furthermore, we propose three operation regimes: the readout, the potentiation in gradual RS, and the abrupt RS. Our results prove that the Au/Ti/a-IGZO/SiO2/p+-Si memristors are promising for the monolithic integration of neuromorphic computing systems because the boundary between the gradual and abrupt RS can be controlled by modulating the SiO2 thickness and IGZO work function.

High Voltage Silicon Carbide Devices

1998 ◽  
Vol 512 ◽  
Author(s):  
B. Jayant Baliga
Keyword(s):  
Silicon Carbide ◽  
Breakdown Voltage ◽  
High Voltage ◽  
Impact Ionization ◽  
Voltage Drop ◽  
Schottky Diodes ◽  
Inversion Layer ◽  
Drift Region ◽  
Edge Termination ◽  
Silicon Devices

ABSTRACTProgress made in the development of high performance power rectifiers and switches from silicon carbide are reviewed with emphasis on approaching the 100-fold reduction in the specific on-resistance of the drift region when compared with silicon devices with the same breakdown voltage. The highlights are: (a) Recently completed measurements of impact ionization coefficients in SiC indicate an even higher Baliga's figure of merit than projected earlier. (b) The commonly reported negative temperature co-efficient for breakdown voltage in SiC devices has been shown to arise at defects, allaying concerns that this may be intrinsic to the material. (c) Based upon fundamental considerations, it has been found that Schottky rectifiers offer superior on-state voltage drop than P-i-N rectifiers for reverse blocking voltages below 3000 volts. (d) Nearly ideal breakdown voltage has been experimentally obtained for Schottky diodes using an argon implanted edge termination. (e) Planar ion-implanted junctions have been successfully fabricated using oxide as a mask with high breakdown voltage and low leakage currents by using a filed plate edge termination. (f) High inversion layer mobility has been experimentally demonstrated on both 6H and 4H-SiC by using a deposited oxide layer as gate dielectric. (g) A novel, high-voltage, normally-off, accumulation-channel, MOSFET has been proposed and demonstrated with 50x lower specific on-resistance than silicon devices in spite of using logic-level gate drive voltages. These results indicate that SiC based power devices could become commercially viable in the 21st century if cost barriers can be overcome.

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