Reverse Leakage Currents in High-Voltage 4H-SiC Schottky Diodes

2013 ◽  
Vol 740-742 ◽  
pp. 877-880 ◽  
Author(s):  
Pavel A. Ivanov ◽  
Igor V. Grekhov ◽  
Alexander S. Potapov ◽  
Natalya D. Il'inskaya ◽  
Oleg I. Kon'kov ◽  
...  
Keyword(s):  
Schottky Barrier ◽  
High Voltage ◽  
Elevated Temperatures ◽  
Schottky Diodes ◽  
Thermionic Emission ◽  
Reverse Direction ◽  
Emission Model ◽  
Leakage Currents ◽  
Band Bending ◽  
Current Voltage

High-voltage 4H-SiC Schottky Barrier Diodes (SBDs) and Junction Barrier Schottky (JBS) diodes have been fabricated and evaluated. Current-voltage (I-V) characteristics were measured in a wide temperature range. All diodes fabricated showed nearly ideal forward behavior. For SBDs with Schottky Barrier Height (SBH) of 1.12 eV, the reverse I–V characteristics are described well by the thermionic emission model (at voltages varying from several mV to 2 kV and temperatures ranging from 361 to 470 K) if barrier lowering with increasing band bending is taken into account. For SBDs with SBH of 1.53 eV, no thermionic current was detected in reverse direction at temperatures below ~500 K. The leakage currents appeared only at high reverse voltages and elevated temperatures. The analysis of reverse I-V characteristics allowed to propose dislocation related mechanism of current flow due to the local injection of electrons from metal to semiconductor. It is shown that defect related leakage currents can be significantly reduced by JBS-structure.

scholarly journals The effects of electron irradiation and thermal dependence measurements on 4H-Sic Schottky diode

2017 ◽  
Vol 51 (12) ◽  
pp. 1721
Author(s):  
Sabuhi Ganiyev ◽  
M. Azim Khairi ◽  
D. Ahmad Fauzi ◽  
Yusof Abdullah ◽  
N.F. Hasbullah
Keyword(s):  
Barrier Height ◽  
Ideality Factor ◽  
Elevated Temperatures ◽  
Series Resistance ◽  
Schottky Diodes ◽  
High Energy ◽  
Bias Current ◽  
N Saturation ◽  
Saturation Current ◽  
Current Voltage

In this paper the effects of high energy (3.0 MeV) electrons irradiation over a dose ranges from 6 to 15 MGy at elevated temperatures 298 to 448 K on the current-voltage characteristics of 4H-SiC Schottky diodes were investigated. The experiment results show that after irradiation with 3.0 MeV forward bias current of the tested diodes decreased, while reverse bias current increased. The degradation of ideality factor, n, saturation current, Is, and barrier height, Phib, were not noticeable after the irradiation. However, the series resistance, Rs, has increased significantly with increasing radiation dose. In addition, temperature dependence current-voltage measurements, were conducted for temperature in the range of 298 to 448 K. The Schottky barrier height, saturation current, and series resistance, are found to be temperature dependent, while ideality factor remained constant. DOI: 10.21883/FTP.2017.12.45193.8646

Change of high-voltage conduction mechanism in vertical GaN–on–GaN Schottky diodes at elevated temperatures

2020 ◽  
Vol 13 (7) ◽  
pp. 074001 ◽  
Author(s):  
Abhinay Sandupatla ◽  
Subramaniam Arulkumaran ◽  
Geok Ing Ng ◽  
Kumud Ranjan ◽  
Manato Deki ◽  
...  
Keyword(s):  
High Voltage ◽  
Conduction Mechanism ◽  
Elevated Temperatures ◽  
Schottky Diodes

Impact of Interface Traps on Current-Voltage Characteristics of 4H-SiC Schottky-Barrier Diodes

2014 ◽  
Vol 778-780 ◽  
pp. 710-713 ◽  
Author(s):  
Hamid Amini Moghadam ◽  
Sima Dimitrijev ◽  
Ji Sheng Han
Keyword(s):  
Schottky Barrier ◽  
Schottky Barrier Height ◽  
Schottky Diodes ◽  
Forward Bias ◽  
Interface Traps ◽  
Barrier Heights ◽  
Current Voltage ◽  
Donor Type ◽  
Current Voltage Characteristics ◽  
Expected Values

This paper presents a physical model based on interface traps to explain both the larger barrier heights of practical Schottky diodes in comparison to the theoretically expected values and the appearance of a knee in the log I–V characteristics. According to this model, acceptor-type interface traps near the valance band increase the Schottky barrier height, which shifts the log I–V characteristic to higher forward-bias voltages. In addition to the acceptor traps, donor-type interface traps can appear near the conduction band, and when they do, they cause the knee in the log I–V characteristics as their energy level falls below the Fermi level and the charge associated with these traps changes from positive to neutral.

High Voltage Schottky Barrier Diodes on P-Type SiC using Metal-Overlap on a Thick Oxide Layer as Edge Termination

1999 ◽  
Vol 572 ◽  
Author(s):  
Q. Zhang ◽  
V. Madangarli ◽  
S. Soloviev ◽  
T. S. Sudarshan
Keyword(s):  
Schottky Barrier ◽  
Oxide Layer ◽  
Breakdown Voltage ◽  
Schottky Diodes ◽  
Schottky Barrier Diodes ◽  
Edge Termination ◽  
Forward Current ◽  
Current Voltage ◽  
Thick Oxide Layer ◽  
P Type

ABSTRACTP-type 6H SiC Schottky barrier diodes with good rectifying characteristics upto breakdown voltage as high as 1000V have been successfully fabricated using metal-overlap over a thick oxide layer (∼ 6000 Å) as edge termination and Al as the barrier metal. The influence of the oxide layer edge termination in improving the reverse breakdown voltage as well as the forward current – voltage characteristics is presented. The terminated Schottky diodes indicate a factor of two higher breakdown voltage and 2–3 times larger forward current densities than those without edge termination. The specific series resistance of the unterminated diodes was ∼228 mΩ-cm2, while that of the terminated diodes was ∼84 mΩ-cm2.

Rectifying and Schottky characteristics of a-SixGe1−xOy with metal contacts

2014 ◽  
Vol 92 (7/8) ◽  
pp. 606-610 ◽  
Author(s):  
Md Muztoba ◽  
Mukti Rana
Keyword(s):  
Ohmic Contact ◽  
Infrared Detector ◽  
Schottky Contact ◽  
Thermionic Emission ◽  
Emission Model ◽  
Metal Contacts ◽  
Temperature Changes ◽  
Barrier Heights ◽  
Current Voltage ◽  
Semiconductor Contacts

Metal–semiconductor contacts are a vital part of semiconductor devices as they can form a Schottky barrier or an Ohmic contact. The nature of the contact plays an important role in determining the electrical and physical characteristics of the device and hence is of paramount importance in the operation of the device. In the current work we report the design, fabrication, and current–voltage (I-V) characteristics of microbolometers, a type of infrared detector where the change in temperature changes the resistance of the sensing layer. Eight different types of microbolometers were fabricated using a-SixGe1−x or a-SixGe1−xOy sensing layers and Ti, Cr, Al, Au, Ni, or Ni0.80Cr0.20 metals contacts. It has been observed that bolometers with an a-Si0.15Ge0.85 (Si was lightly p-doped) sensing layer formed a Schottky contact with Ti, Au, Cr, and Al contact metals, while bolometers with a-Si0.15Ge0.85 (Si was heavily n-doped) sensing layers formed an Ohmic contact with Au. For microbolometers with a Si0.15Ge0.85O0.039 sensing layer, both Ni and Ni0.80Cr0.20 contact metals formed the Ohmic contact. For a-SixGe1−x and a-SixGe1−xOy microbolometers, Au and Ni0.80Cr0.20 were used as the absorber layers, respectively. The I–V characteristics of the microbolometers were analyzed with a thermionic emission model. A linear dependence on the Ge composition was approximated to find the effective Richardson constant. The theory predicts Richardson constants of 112 and 50 A/cm2K2 for Si and Ge, respectively. Barrier heights of all devices are calculated and the reasons for the formation of the Ohmic and Schottky contacts are discussed.

Performance of Pt-based Low Schottky Barrier Silicide Contacts on Weakly Doped Silicon

2003 ◽  
Vol 765 ◽  
Author(s):  
Guilhem Larrieu ◽  
Emmanuel Dubois ◽  
Xavier Wallart
Keyword(s):  
Schottky Barrier ◽  
Cross Sections ◽  
Ohmic Contacts ◽  
Thermionic Emission ◽  
Current Drive ◽  
Silicon On Insulator ◽  
Grand Challenge ◽  
Electrical Measurements ◽  
Temperature Dependent ◽  
Current Voltage

AbstractOne of the grand challenge imposed by CMOS down-scaling is the optimisation of the source/drain (S/D) architecture, e.g., dopant activation above solid solubility, steep dopant profiling, low silicide specific contact resistivity. Recently, the concept of very low Schottky barrier S/D MOSFET has emerged as a possible alternative to conventional architecture using highly doped S/D and midgap silicide ohmic contacts. For p-MOSFETs integration, platinum silicide is an excellent candidate because of its very low barrier to holes. This enables the use of a weakly doped substrate that inherently solves the aforementioned challenges due to highly doped S/D. This paper proposes a detailed study of the platinum silicidation reaction obtained by rapid thermal annealing. The analysis is based on X-ray photoemission spectroscopy (XPS), transmission electron miscrocopy (TEM) and low temperature-dependent current-voltage measurements. Using XPS analysis, it is shown that: i) an initial silicide layer is formed at room temperature, ii) three stable phases Pt, Pt2Si, PtSi can not coexist providing that iii) the annealing ambience is strictly controlled to avoid the formation of a SiO2 barrier due to oxygen penetration into the platinum overlayer. Starting from an initial 15 nm thick Pt layer subsequently annealing at 300°C, TEM cross-sections reveal that homogeneous 32 nm PtSi layers with a uniform grain size distribution are formed. Finally, current-voltage characteristics have been measured on a special test structure that accounts for the lateral disposition of S/D regions in a typical MOSFET architecture. It consists in two back-to-back Schottky contacts separated by a narrow silicon gap both on bulk silicon and Silicon-On-Insulator (SOI) substrates. Based on temperature-dependent electrical measurements (Arrhenius plot), it is shown that field emission is involved in the current transport mechanism, in addition to thermionic emission. An excellent current drive performance of 220 μA per micron width has been obtained for a 45 nm silicon gap on a 10 nm thick SOI substrate.

Schottky Barrier Height Dependence on the Metal Work Function for p-type Si Schottky Diodes

2004 ◽  
Vol 59 (11) ◽  
pp. 795-798 ◽  
Author(s):  
Güven Çankaya ◽  
Nazım Uçar
Keyword(s):  
Fermi Level ◽  
Schottky Barrier ◽  
Schottky Diodes ◽  
Metal Work Function ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Work Functions ◽  
P Type ◽  
Relationship Of ◽  
Metal Work

We investigated Schottky barrier diodes of 9 metals (Mn, Cd, Al, Bi, Pb, Sn, Sb, Fe, and Ni) having different metal work functions to p-type Si using current-voltage characteristics. Most Schottky contacts show good characteristics with an ideality factor range from 1.057 to 1.831. Based on our measurements for p-type Si, the barrier heights and metal work functions show a linear relationship of current-voltage characteristics at room temperature with a slope (S=ϕb/ϕm) of 0.162, even though the Fermi level is partially pinned. From this linear dependency, the density of interface states was determined to be about 4.5 · 1013 1/eV per cm2, and the average pinning position of the Fermi level as 0.661 eV below the conduction band

Electronic Properties of ZnO Varistors: A New Model

1981 ◽  
Vol 5 ◽  
Author(s):  
G. E. Pike
Keyword(s):  
Grain Boundaries ◽  
Impact Ionization ◽  
Thermionic Emission ◽  
Low Frequency ◽  
Charge Trapping ◽  
Emission Model ◽  
Zero Bias ◽  
Current Voltage ◽  
Zno Varistors ◽  
Dc Current

ABSTRACTMuch of the research on ZnO varistors has concentrated on the explanation of their dc current-voltage characteristics. However, varistors also have unusual ac properties which can be technologically important, and must be described by any comprehensive model. In an ideal varistor with identical grain boundaries throughout, there should be no dispersive capacitance at zero bias. In real varistors this capacitance varies considerably with frequency. This dispersion has two causes, charge trapping in the depletion regions and differing grain boundary barriers. Calculations for each process are given. For voltages well below the varistor breakdown value, the low frequency capacitance increases with applied voltage. At even higher voltages the capacitance turns over and becomes negative. All of these effects can be described with a double depletion layer/thermionic emission model. The anomalous capacitance behavior with bias is due to the modulation of the potential barriers by charge trapping at the grain boundaries. In the varistor breakdown regime minority carriers created by impact ionization are important.

Fabrication of 3.4kV high voltage n-type 4H-SiC Schottky barrier diodes using thick epitaxial layers

2000 ◽  
Vol 640 ◽  
Author(s):  
Takashi Tsuji ◽  
Hiroyuki Fujisawa ◽  
Shinji Ogino ◽  
Hidekazu Tsuchida ◽  
Isaho Kamata ◽  
...  
Keyword(s):  
Schottky Barrier ◽  
High Voltage ◽  
High Yield ◽  
Epitaxial Layers ◽  
Schottky Barrier Diodes ◽  
Leakage Currents ◽  
Bright Spots ◽  
Blocking Voltage ◽  
Voltage Region ◽  
The Ideal

ABSTRACTFabrication and evaluation of high voltage n-type 4H-SiC Schottky barrier diodes (SBDs) using 27μm thick epitaxial layers were presented. To achieve the ideal value of the breakdown voltage, various parameters of junction termination extension (JTE) were investigated. We concluded that the termination of triple rings with the concentrations of 6×1017, 3×1017, 1.5×1017cm−1 outwardly was best with the simulations. The SBDs with this termination showed the blocking voltage up to 3.4kV, which is almost the ideal value. We also investigated the distribution of leakage currents at -600V in SBDs with various diameters up to 4mm. High yield was obtained in the SBDs with the diameters below 2mm. The SBDs with high leakage currents showed the excess currents in the low forward voltage region and lots of bright spots could be observed by optical beam induced current analysis.

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