4H-SiC Trench Schottky Diodes for Next Generation Products

2013 ◽  
Vol 740-742 ◽  
pp. 781-784 ◽  
Author(s):  
Qing Chun Jon Zhang ◽  
Jennifer Duc ◽  
Van Mieczkowski ◽  
Brett Hull ◽  
Scott Allen ◽  
...  
Keyword(s):  
Leakage Current ◽  
Doping Concentration ◽  
Schottky Diodes ◽  
Size Reduction ◽  
High Current ◽  
Next Generation ◽  
Electrical Field ◽  
Reverse Leakage Current ◽  
Chip Size ◽  
Order Of Magnitude

A novel trench JBS structure has been developed to reduce the electrical field at the Schottky interface. Compared to the conventional planar JBS structure, the new design has reduced the reverse leakage current by 1 order of magnitude at rated voltage. The much reduced field at the Schottky interface allows an increase in the drift doping concentration, which enables a significant chip size reduction on next generation SiC Schottky diodes. This progress makes it possible to fabricate high current rating (>50 A) SiC diodes for module applications.

Electrical Characteristics of Large Chip-Size 3.3 kV SiC-JBS Diodes

2013 ◽  
Vol 740-742 ◽  
pp. 881-886 ◽  
Author(s):  
Hiroyuki Okino ◽  
Norifumi Kameshiro ◽  
Kumiko Konishi ◽  
Naomi Inada ◽  
Kazuhiro Mochizuki ◽  
...  
Keyword(s):  
Electric Field ◽  
Schottky Barrier ◽  
Leakage Current ◽  
Reverse Current ◽  
Tunneling Current ◽  
Leakage Currents ◽  
Reverse Leakage Current ◽  
Low Leakage ◽  
Chip Size ◽  
Barrier Metal

The reduction of reverse leakage currents was attempted to fabricate 4H-SiC diodes with large current capacity for high voltage applications. Firstly diodes with Schottky metal of titanium (Ti) with active areas of 2.6 mm2 were fabricated to investigate the mechanisms of reverse leakage currents. The reverse current of a Ti Schottky barrier diode (SBD) is well explained by the tunneling current through the Schottky barrier. Then, the effects of Schottky barrier height and electric field on the reverse currents were investigated. The high Schottky barrier metal of nickel (Ni) effectively reduced the reverse leakage current to 2 x 10-3 times that of the Ti SBD. The suppression of the electric field at the Schottky junction by applying a junction barrier Schottky (JBS) structure reduced the reverse leakage current to 10-2 times that of the Ni SBD. JBS structure with high Schottky barrier metal of Ni was applied to fabricate large chip-size SiC diodes and we achieved 30 A- and 75 A-diodes with low leakage current and high breakdown voltage of 4 kV.

Investigation of Stacking Faults Affecting on Reverse Leakage Current of 4H-SiC Junction Barrier Schottky Diodes Using Device Simulation

2014 ◽  
Vol 778-780 ◽  
pp. 828-831 ◽  
Author(s):  
Junichi Hasegawa ◽  
Kazuya Konishi ◽  
Yu Nakamura ◽  
Kenichi Ohtsuka ◽  
Shuhei Nakata ◽  
...  
Keyword(s):  
Schottky Barrier ◽  
Barrier Height ◽  
Leakage Current ◽  
Schottky Barrier Height ◽  
Schottky Diodes ◽  
Stacking Faults ◽  
Metal Electrode ◽  
Reverse Leakage Current ◽  
Electrode Interface ◽  
The Relationship

We clarified the relationship between the enhanced leakage current of SiC Junction Barrier Schottky diodes and the stacking faults in the SiC crystal at the SiC and metal electrode interface by measuring the electrical and optical properties, and confirm by using the numerical simulations. Numerical simulation considering local lowering of Schottky barrier height, which is 0.8 eV lower than that of 4H-SiC well explained the 2-4 orders of magnitude higher reverse leakage current caused by the SFs. We concluded that the locally lowering of the Schottky barrier height at the 3C-SiC layer in the 4H-SiC surface is a main cause of the large reverse leakage current.

A new process for decreasing reverse leakage current of PtSi/Si power Schottky diodes

Vacuum ◽  
1991 ◽  
Vol 42 (16) ◽  
pp. 1094
Author(s):  
Zhao Shulan ◽  
Yu Jiafong ◽  
Yang Yali ◽  
Liu Shuqin ◽  
Liu Shuqin ◽  
...  
Keyword(s):  
Leakage Current ◽  
Schottky Diodes ◽  
Reverse Leakage Current ◽  
New Process

NOVEL HIGH TEMPERATURE ANNEALED SCHOTTKY METAL FOR GaN DEVICES

2011 ◽  
Vol 20 (03) ◽  
pp. 417-422
Author(s):  
QUENTIN DIDUCK ◽  
IAN WALSH ◽  
DUBRAVKO BABIĆ ◽  
LESTER F. EASTMAN
Keyword(s):  
High Temperature ◽  
Schottky Barrier ◽  
Barrier Height ◽  
Leakage Current ◽  
Ohmic Contacts ◽  
Schottky Diodes ◽  
Metal System ◽  
Gan Hemt ◽  
Order Of Magnitude ◽  
Alignment Marks

We have found that Scandium metal is near ohmic as deposited on GaN , but when it is annealed at high temperatures a large barrier height Schottky forms. In this study we used Sc - Au contacts to form Schottky barrier diodes on AlGaN / GaN HEMT material. We have found that the morphology remains unchanged even after an 800 degrees centigrade anneal. This investigation has revealed that the reverse leakage current of this metal system is an order of magnitude lower than a conventional Ni - Au contact and supports a reverse breakdown that is 1/3rd larger. The similarity of the anneal temperatures to ohmic contacts enable gates and contacts to be annealed at the same time thus simplifying processing. The lack of morphology change supports the use of Sc - Au for E -beam alignment marks as well. Diode contacts on AlGaN / GaN with Schottky-ohmic separation of 10 microns demonstrated reverse breakdown in excess of 100V when the contacts were annealed at 800C. These results suggest this metallization may have applications as a new HEMT gate metal, and Schottky diodes.

scholarly journals Reduction of reverse leakage current at the TiO2/GaN interface in field plate Ni/Au/n-GaN Schottky diodes

2021 ◽  
Vol 24 (04) ◽  
pp. 399-406
Author(s):  
A.M. Goriachko ◽  
◽  
M.V. Strikha ◽  
◽  
Keyword(s):  
Leakage Current ◽  
Schottky Diode ◽  
Schottky Diodes ◽  
Electrical Characteristics ◽  
Temperature Dependent ◽  
Field Plate ◽  
Reverse Leakage Current ◽  
Plate Length ◽  
Fabrication Procedure ◽  
Field Oxide

This paper presents the fabrication procedure of TiO2 passivated field plate Schottky diode and gives a comparison of Ni/Au/n-GaN Schottky barrier diodes without field plate and with field plate of varying diameters from 50 to 300 µm. The influence of field oxide (TiO2) on the leakage current of Ni/Au/n-GaN Schottky diode was investigated. This suggests that the TiO2 passivated structure reduces the reverse leakage current of Ni/Au/n-GaN Schottky diode. Also, the reverse leakage current of Ni/Au/n-GaN Schottky diodes decreases as the field plate length increases. The temperature-dependent electrical characteristics of TiO2 passivated field plate Ni/Au/n-GaN Schottky diodes have shown an increase of barrier height within the temperature range 300…475 K.

Mechanisms and Characteristics of Large-Area High-Current-Density 4H-SiC Trench Junction Barrier Schottky Diodes

2019 ◽  
Vol 963 ◽  
pp. 562-566
Author(s):  
Yi Dan Tang ◽  
Sheng Xu Dong ◽  
Yun Bai ◽  
Cheng Yue Yang ◽  
Cheng Zhan Li ◽  
...  
Keyword(s):  
Leakage Current ◽  
Current Density ◽  
Small Area ◽  
High Current Density ◽  
Schottky Diodes ◽  
High Current ◽  
Large Area ◽  
Reverse Blocking ◽  
Experimental Values ◽  
Surface Leakage

Mechanisms and characteristics of optimized main junction for 4H-SiC trench junction barrier Schottky (TMJBS) diodes were investigated by theories and experiments. From these simulation and experimental values, we can conclude that TMJBS device has better reverse performance, such as the best reverse blocking capability and lowest reverse surface leakage current than the conventional JBS and TJBS device while maintaining good forward characteristics. Furthermore, The large area TMJBS Diodes with high current density show the better reverse characteristics than the small area one at an acceptable forward characteristics. The TMJBS structure can significantly reduce the influence of the Schottky interface and is more suitable for manufacturing high current density and large area devices.

4.5 kV SiC Junction Barrier Schottky Diodes with Low Leakage Current and High Forward Current Density

2017 ◽  
Vol 897 ◽  
pp. 427-430 ◽  
Author(s):  
Johannes Schoeck ◽  
Jonas Buettner ◽  
Mathias Rommel ◽  
Tobias Erlbacher ◽  
Anton J. Bauer
Keyword(s):  
Leakage Current ◽  
Breakdown Voltage ◽  
Current Density ◽  
Voltage Drop ◽  
Schottky Diodes ◽  
Low Leakage ◽  
Forward Current ◽  
Low Leakage Current ◽  
Forward Voltage Drop ◽  
Chip Size

High-voltage 4H-SiC Junction Barrier Schottky diodes with a reverse breakdown voltage of over 4.5 kV and a turn-on voltage below 1 V have been fabricated. They achieved a forward current of 5 A at a forward voltage drop of 1.8 V and 20 A at 4.2 V. A low reverse leakage current of 0.3 μA at 1.2 kV and 37 μA at 3.3 kV was measured. The chip size was 7.3 mm x 7.3 mm, the active area 0.25 cm2 and the diode was able to handle a repetitive pulse current density of over 300 A/cm2 without degradation. Floating field rings in combination with a field-stop ring were used as edge termination to reach 73 % of the theoretical breakdown voltage. The epitaxial layer was 32 μm thick, with a nitrogen doping concentration of 1 x 1015 cm-3. The JBS diodes have been manufactured in a 100 mm SiC prototyping line, using well established processing technology, to achieve cost-efficient devices.

J-V Characteristics of Al+ Ion Implanted p+/n 4H-SiC Diodes Annealed in Silane Ambient at 1600°C

2005 ◽  
Vol 483-485 ◽  
pp. 629-632 ◽  
Author(s):  
Fabio Bergamini ◽  
Shailaja P. Rao ◽  
Stephen E. Saddow ◽  
Roberta Nipoti
Keyword(s):  
Leakage Current ◽  
Room Temperature ◽  
High Resistivity ◽  
Reverse Leakage Current ◽  
Current Voltage ◽  
Exponential Trend ◽  
Order Of Magnitude ◽  
Current Value ◽  
Post Implantation ◽  
Positive Results

Al+ implanted p+/n 4H-SiC diodes were realized via planar technology. The p+/n junctions were obtained by hot implantation at 400°C, followed by a post implantation annealing at 1600°C in Silane ambient. 136 diodes and other test structures were measured: the current voltage^curves and the resistivity of the implanted layer were investigated at room temperature. The majority of the measured diodes had a turn on voltage of about 1.75 V, a forward characteristic with exponential trend and ideality factor equal to 1.2, and a very low spread in the distribution of the reverse leakage current values at –100V. The average reverse leakage current value is (9.7 ± 0.4) × 10-9 A/cm2. The breakdown voltage of these diodes approached the theoretical value for the use epitaxial 4H-SiC layer, i.e. 0.75 – 1.0 kV. All these positive results are penalized by the high resistivity value of the implanted Al+ layer, which amounts to 11 W·cm that is one order of magnitude higher than the desired value.

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