Simulation study for GaN-based hybrid trench MOS barrier Schottky diode with an embedded p-type NiO termination: increased forward current density and enhanced breakdown voltage

Author(s):  
Fuping Huang ◽  
Chunshuang Chu ◽  
Xingyu Jia ◽  
Kangkai Tian ◽  
Yonghui Zhang ◽  
...  

Abstract In this work, a hybrid trench MOS barrier Schottky diode (TMBS) structure is proposed to improve both the forward current density and the breakdown voltage (BV) by using TCAD simulation tools. The hybrid structure means that the conventional TMBS rectifier is combined with a p-NiO/n-GaN diode. This can modulate the lateral energy bands by removing the conduction band barriers for electrons. Thus, the improved current spreading effect and the better conductivity modulation can be obtained, leading to the increased current density. Meanwhile, the embedded p-type NiO layer can also help to reduce the electric field at Schottky contact interface and the edge of anode contact/p-NiO layer interface. Thus, the breakdown voltage can be improved remarkably. Moreover, a detailed optimization strategy for the hybrid TMBS is also analyzed by varying the p-NiO layer thickness (TNiO) and the lengths of the anode electrode that is covered on the p-NiO layer (LA).

2011 ◽  
Vol 20 (3) ◽  
pp. 285-289 ◽  
Author(s):  
P. Muret ◽  
P.-N. Volpe ◽  
T.-N. Tran-Thi ◽  
J. Pernot ◽  
C. Hoarau ◽  
...  

2016 ◽  
Vol 858 ◽  
pp. 986-989 ◽  
Author(s):  
Hao Yuan ◽  
Qing Wen Song ◽  
Xiao Yan Tang ◽  
Yu Ming Zhang ◽  
Hui Guo ◽  
...  

In this paper, a 5.7kV 4H-SiC Junction Barrier Schottky diode(JBS) with non-uniform field limiting rings termination is simulated and fabricated successfully based on a epitaxial thickness of 49μm and the doping concentration about 1.04×1015cm-3 respectively. The reverse breakdown voltage could reach to 5.7kV at least at reverse current of 200μA. And the on-state voltage is 3V at the forward current of 2A, corresponding to an on-resistance of 32mΩ•cm2. The corresponding figure-of- merit of VB2/ RSP-ON for our fabricated device is 1.026 GW/cm2, which is closing to the optimal levels among several reported SiC JBS.


1999 ◽  
Vol 572 ◽  
Author(s):  
Q. Zhang ◽  
V. Madangarli ◽  
S. Soloviev ◽  
T. S. Sudarshan

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.


Author(s):  
Z. Mouffak ◽  
N. Medelci-Djezzar ◽  
C. Boney ◽  
A. Bensaoula ◽  
L. Trombetta

Reactive Ion Etching (RIE) and Photo-Assisted RIE (PA-RIE) induced damage in GaN using simple Schottky structures and a BCl3/Cl2/N2gas mixture have been investigated. Schottky diode I-V characteristics following different RF powers and exposure times show significant changes caused by damage. This damage results in a reduction of the reverse breakdown voltage VB in n-type GaN and an increase in VB for p-type GaN. Our preliminary data on the PA-RIE process points to much reduced damage levels compared to conventional RIE. This result may be due to a change in surface chemistry or to a photo-enhanced diffusion of defects into the GaN layer, leaving a cleaner near-surface region.


Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7096
Author(s):  
Xiaochuan Deng ◽  
Rui Liu ◽  
Songjun Li ◽  
Ling Li ◽  
Hao Wu ◽  
...  

A silicon carbide (SiC) trench MOSFET featuring fin-shaped gate and integrated Schottky barrier diode under split P type shield (SPS) protection (FS-TMOS) is proposed by finite element modeling. The physical mechanism of FS-TMOS is studied comprehensively in terms of fundamental (blocking, conduction, and dynamic) performance and transient extreme stress reliability. The fin-shaped gate on the sidewall of the trench and integrated Schottky diode at the bottom of trench aim to the reduction of gate charge and improvement on the third quadrant performance, respectively. The SPS region is fully utilized to suppress excessive electric field both at trench oxide and Schottky contact when OFF-state. Compared with conventional trench MOSFET (C-TMOS), the gate charge, Miller charge, Von at third quadrant, Ron,sp·Qgd, and Ron,sp·Qg of FS-TMOS are significantly reduced by 34%, 20%, 65%, 0.1%, and 14%, respectively. Furthermore, short-circuit and avalanche capabilities are discussed, verifying the FS-TMOS is more robust than C-TMOS. It suggests that the proposed FS-TMOS is a promising candidate for next-generation high efficiency and high-power density applications.


2017 ◽  
Vol 5 (1) ◽  
pp. 11
Author(s):  
S.B. Rybalka ◽  
E.Yu. Krayushkina ◽  
A.A. Demidov ◽  
O.A. Shishkina ◽  
B.P. Surin

Forward current-voltage characteristics of 4H-SiC Schottky diode with Ni Schottky contact have been simulated based on in the physical analytical models based on Poisson’s equation, drift-diffusion and continuity equations. On the base of analysis of current-voltage characteristics in terms of classical thermionic emission theory it is established that the proposed simulation model of Schottky diode corresponds to the “ideal” diode with average ideality factor n»1.1 at low temperature ~300 K. It is determined that effective Schottky barrier height equals 1.1 eV for Ni/4H-SiC Schottky diode.


Author(s):  
Walid Filali ◽  
Slimane Oussalah ◽  
Noureddine Sengouga ◽  
Mohamed Henini ◽  
David Taylor

2017 ◽  
Vol 897 ◽  
pp. 427-430 ◽  
Author(s):  
Johannes Schoeck ◽  
Jonas Buettner ◽  
Mathias Rommel ◽  
Tobias Erlbacher ◽  
Anton J. Bauer

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.


2006 ◽  
Vol 517 ◽  
pp. 159-164
Author(s):  
Tarriq Munir ◽  
Azlan Abdul Aziz ◽  
Mat Johar Abdullah ◽  
Naser Mahmoud Ahmed

We focus on the epi layer carrier concentration variation effects to improve the current – voltage (I-V) characteristics of an n-GaN schottky diode. The carrier concentration of 1×10 15cm-3, 1×1016 cm−3, 1×1017 cm−3 were employed. The simulated current was obtained by forward biasing the device of up to 2Volt at room temperature using Pt electrode. The study was conducted by using Atlas/Blaze using various models such as Consrh (Concentration Dependent Shockley Read Hall), Cvt (Lombardi Model), Fermi (Fermi Dirac), Bgn (Bandgap Narrowing), Conmob (Concentration Dependent Mobility), Auger (Auger). We found that as the concentration increases the value of forward current also increase linearly when biased at maximum of 2 volts. The reverse bias characteristics at the same concentration of the simulated diode up to 100Volt were also determined. We found that at low carrier concentration the reverse leakage current is minimum and breakdown voltage is maximum. As the carrier concentration increases there is a linear relationship between reverse leakage current and epi layer doping carrier concentration. By analyzing the forward and reverse characteristics we conclude that in forward bias for low carrier concentration the diode shows schottky rectifying behavior while for higher carrier concentration the diode shows ohmic behavior. For higher carrier concentration there is a linear relationship between carrier concentration (n) and forward current. The reverse leakage current is minimum approaching an ideal value at n≤1×1015cm-3 and breakdown voltage is maximum at these values of concentration. Increasing the concentration from n≤1×1015cm-3 the value of reverse leakage current is approaching to the maximum value as a result breakdown voltage decreases. We conclude that for n-GaN schottky diode the ideal schottky rectifying behavior of I-V characteristics is obtained at carrier concentration of n≤ 1×1015cm-3 for the simulated diodes at different carrier concentration.


2021 ◽  
Author(s):  
Yun Xia ◽  
Wanjun Chen ◽  
Bo Zhang ◽  
Zhaoji Li

Abstract A novel superjunction MOSFET (SJ-MOSFET) for ultralow reverse recovery charge (Q RR ) and low switching loss is proposed and investigated. This device features a P-type Schottky diode and a source field-plate. The P-type Schottky diode consists of Schottky contact and P-base, which is reverse series-connected with body P-N junction diode. And the source field-plate is formed by implementing a polysilicon field-plate electrically coupled to the source, which is on the top of N-pillar. During the reverse conduction state, the P-type Schottky diode is reverse biased, which dramatically suppresses minority carriers injecting into the drift region. Simultaneously, electron accumulation layer formed under the source field-plate, which provides a path for the reverse current. Consequently, compared with the conventional SJ-MOSFET (Conv-SJ-MOSFET), the proposed SJ-MOSFET achieves an 84.0% lower Q RR with almost no sacrifice in other characteristics. Moreover, the proposed device also exhibits 47.4% and 66.0% lower gate charge (Q G ) and gate to drain charge (Q GD ), respectively. The significantly reduced Q G , Q GD , and Q RR contribute to an overall improvement in switching losses and resultant over 54.8% decrease in total power losses with operation frequency higher than 50 kHz, demonstrating great potential of the proposed SJ-MOSFET used in power conversion systems.


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