Doping Concentration Optimization for Ultra-Low-Loss 4H-SiC Floating Junction Schottky Barrier Diode (Super-SBD)

2009 ◽  
Vol 615-617 ◽  
pp. 655-658 ◽  
Author(s):  
Chiharu Ota ◽  
Johji Nishio ◽  
Kazuto Takao ◽  
Tetsuo Hatakeyama ◽  
Takashi Shinohe ◽  
...  
Keyword(s):  
Schottky Barrier ◽  
Breakdown Voltage ◽  
Dynamic Characteristics ◽  
Figure Of Merit ◽  
Doping Concentration ◽  
Drift Region ◽  
Static Characteristics ◽  
Low Loss ◽  
Significant Lowering ◽  
Floating Layer

Previous simulation works and experiments on the loss of 4H-SiC floating junction Schottky barrier diodes (Super-SBDs) show that the loss is related to the doping concentration in the drift region and the pattern of the floating layer. The effect of the doping concentration for lowering the loss is characterized the breakdown voltage (Vbd) and the on-state resistances (RonS) of the Super-SBDs based on Baliga’s figure of Merit (BFOM). Experimental devices with two doping concentrations in the drift region are fabricated to investigate the static characteristics: Vbd and RonS. The Vbd of the Super-SBDs is close to the simulation result, near 3000 V. However the tendency of the Vbd by the doping concentration is not similar to the simulation result. And the RonS are about 3.22 mcm2 which is higher than that of simulation result. The doping concentration optimized in this study does not show significant lowering loss and the design of the floating layer in the termination region affect the low-loss static characteristics of the Super-SBD. In addition, adopting PiN structure with floating layer (Super-PiN) affects the low-loss dynamic characteristics, optimizing the doping concentration in the drift region. We conclude that the fabricated Super-SBDs with the floating layer in the termination region, the drift region with a doping concentration of 1.01016 cm-3 and mesa-shaped termination structure, have excellent Vbd of 2990 V which is almost same as that of simulation result and RonS of 3.22 mcm2.

Fabrication of 4H-SiC Floating Junction Schottky Barrier Diodes (Super-SBDs) and their Electrical Properties

2006 ◽  
Vol 527-529 ◽  
pp. 1175-1178 ◽  
Author(s):  
Chiharu Ota ◽  
Johji Nishio ◽  
Tetsuo Hatakeyama ◽  
Takashi Shinohe ◽  
Kazutoshi Kojima ◽  
...  
Keyword(s):  
Schottky Barrier ◽  
Breakdown Voltage ◽  
Figure Of Merit ◽  
Schottky Barrier Diodes ◽  
P Type ◽  
The Relationship ◽  
Unipolar Devices ◽  
Theoretical Limitation ◽  
State Resistance ◽  
Floating Layer

4H-SiC floating junction Schottky barrier diodes (Super-SBDs) were fabricated. It was found that their properties are closest to the theoretical limitation, defined by the relationship between specific on-state resistance and breakdown voltage of 4H SiC-unipolar devices. They have a p-type floating layer designed as line-and-spacing. The specific on-state resistances of Super-SBDs with a few micrometers of spacing width were found to be nearly equal to those of conventional SBDs without p-type floating layer. The breakdown voltages of Super-SBDs were higher than those of conventional SBDs. Accordingly the properties of Super-SBDs have improved the trade-off between specific on-state resistance and breakdown voltage, and the highest value to date for Baliga’s Figure of Merit (BFOM) has been obtained.

Epitaxial Growth and Characterization of 4H-SiC(11–20) and (03–38)

2002 ◽  
Vol 742 ◽  
Author(s):  
T. Kimoto ◽  
K. Hashimoto ◽  
K. Fujihira ◽  
K. Danno ◽  
S. Nakamura ◽  
...  
Keyword(s):  
Epitaxial Growth ◽  
Schottky Barrier ◽  
Breakdown Voltage ◽  
Doping Concentration ◽  
Schottky Barrier Diodes ◽  
Homoepitaxial Growth ◽  
Nitrogen Incorporation ◽  
Impurity Doping ◽  
Background Doping

ABSTRACTHomoepitaxial growth, impurity doping, and diode fabrication on 4H-SiC(11–20) and (03–38) have been investigated. Although the efficiency of nitrogen incorporation is higher on the non-standard faces than on (0001), a low background doping concentration of 2∼3×1014 cm-3 can be achieved. On these faces, boron and aluminum are less effectively incorporated, compared to the growth on off-axis (0001). 4H-SiC(11–20) epilayers are micropipe-free, as expected. More interestingly, almost perfect micropipe closing has been realized in 4H-SiC (03–38) epitaxial growth. Ni/4H-SiC(11–20) and (03–38) Schottky barrier diodes showed promising characteritics of 3.36 kV-24 mΩcm2 and 3.28 kV–22 mΩcm2, respectively. The breakdown voltage of 4H-SiC(03–38) Schottky barrier diodes was significantly improved from 1 kV to above 2.5 kV by micropipe closing.

High-Breakdown-Voltage GaN Vertical Schottky Barrier Diodes with Field Plate Structure

2009 ◽  
Vol 615-617 ◽  
pp. 963-966 ◽  
Author(s):  
Taku Horii ◽  
Tomihito Miyazaki ◽  
Yu Saito ◽  
Shin Hashimoto ◽  
Tatsuya Tanabe ◽  
...  
Keyword(s):  
Schottky Barrier ◽  
Breakdown Voltage ◽  
Figure Of Merit ◽  
Schottky Barrier Diodes ◽  
Field Plate ◽  
Forward Current ◽  
Low Dislocation Density ◽  
Current Voltage ◽  
Dislocation Densities ◽  
Current Voltage Characteristics

Gallium nitride (GaN) vertical Schottky barrier diodes (SBDs) with a SiNx field plate (FP) structure on low-dislocation-density GaN substrates have been designed and fabricated. We have successfully achieved the SBD breakdown voltage (Vb) of 680V with the FP structure, in contrast to that of 400V without the FP structure. There was no difference in the forward current-voltage characteristics with a specific on-resistance (Ron) of 1.1mcm2. The figure of merit V2b/Ron of the SBD with the FP structure was 420MWcm-2. The FP structure and the high quality drift layers grown on the GaN substrates with low dislocation densities have greatly contributed to the obtained results.

High Performance of 5.7kV 4H-SiC JBSs with Optimized Non-Uniform Field Limiting Rings Termination

2016 ◽  
Vol 858 ◽  
pp. 986-989 ◽  
Author(s):  
Hao Yuan ◽  
Qing Wen Song ◽  
Xiao Yan Tang ◽  
Yu Ming Zhang ◽  
Hui Guo ◽  
...  
Keyword(s):  
Breakdown Voltage ◽  
Schottky Diode ◽  
High Performance ◽  
Figure Of Merit ◽  
Doping Concentration ◽  
Reverse Current ◽  
Uniform Field ◽  
Forward Current

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.

scholarly journals A Novel LDMOS with Ultralow Specific on-Resistance and Improved Switching Performance

2021 ◽  
Author(s):  
Lijuan Wu ◽  
Haifeng Wu ◽  
Jinsheng Zeng ◽  
Xing Chen ◽  
Shaolian Su
Keyword(s):  
Breakdown Voltage ◽  
Current Distribution ◽  
Doping Concentration ◽  
Electric Field Distribution ◽  
Drift Region ◽  
Optimal Doping ◽  
Field Plate ◽  
Switching Performance ◽  
Switching Losses ◽  
Optimal Doping Concentration

Abstract A stepped split triple-gate SOI LDMOS with P/N strip (P/N SSTG SOI LDMOS) is proposed, which has ultralow specific on-resistance (Ron,sp) and low switching losses. The proposed device has a triple-gate (TG) and stepped split gates (SSGs). P strip, N-drift and oxide trench are alternately arranged in the Z direction. Meanwhile, the SSGs are located in the oxide trench of the N-drift region and are distributed in steps. Firstly, the TG increases the channel width (Wch) and has the effect of modulating current distribution, resulting in lower Ron,sp and higher transconductance (gm). Secondly, the SSGs serve as the field plate to assist the depletion of the N-drift region, increasing the optimal doping concentration of the N-drift region (Nd-opt) and further reducing the Ron,sp. Moreover, the SSGs also have the effect of modulating the electric field distribution to maintain a high breakdown voltage (BV). Meanwhile, gate-drain charge (QGD) and switching losses are reduced on account of the introduction of the SSGs. Thirdly, in the off-state, the P strip and SSGs multidimensional assisted depletion of the N-drift region, which greatly increases the Nd-opt. The highly doped N-drift region provides a low-resistance path for the current, which also further reduces Ron,sp. Compared with triple-gate (TG) SOI LDMOS with almost equal breakdown voltage, the Ron,sp and QGD of P/N SSTG SOI LDMOS are reduced by 62% and 63%, respectively.

scholarly journals Enhancing Breakdown Voltage of a Ga2O3 Schottky Barrier Diode with Small-Angle Beveled and High-k Oxide Field Plate

2021 ◽  
Author(s):  
Dinghe Liu ◽  
Yuwen Huang ◽  
Zeyulin Zhang ◽  
Dazheng Chen ◽  
Qian Feng ◽  
...  
Keyword(s):  
Schottky Barrier ◽  
Breakdown Voltage ◽  
Small Angle ◽  
Dielectric Layer ◽  
Figure Of Merit ◽  
Field Plate ◽  
Breakdown Mechanism ◽  
High K ◽  
High K Dielectric ◽  
Drift Layer

Abstract To increase their breakdown voltage, Ga2O3 Schottky barrier diodes (SBDs) with a beveled field plate were designed based on TCAD platform simulations. The small-angle beveled field plate can effectively alleviate the electric field concentration effect. The breakdown voltage of Ga2O3 SBDs can reach 1217 V with the SiO2 dielectric and a small-angle (1°) beveled field plate. However, the breakdown mechanism is the early breakdown of the dielectric layer. TO further increase the breakdown voltage, the replacement of SiO2 with a high-k dielectric (Al2O3 and HfO2) can transfer the breakdown location into the Ga2O3 drift layer. By combining the beveled small-angle design and the high-k dielectric, the device demonstrates a Baliga’s figure of merit of 2.94 GW/cm2 and breakdown voltage of 3108V.

scholarly journals Gate Current and Snapback of 4H-SiC Thyristors on N+ Substrate for Power-Switching Applications

Electronics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 332
Author(s):  
Hojun Lee ◽  
Ogyun Seok ◽  
Taeeun Kim ◽  
Min-Woo Ha
Keyword(s):  
Numerical Simulation ◽  
Breakdown Voltage ◽  
Doping Concentration ◽  
Voltage Drop ◽  
Depletion Region ◽  
Drift Region ◽  
Power Switching ◽  
Gate Current ◽  
High Voltage Direct Current ◽  
Forward Voltage Drop

High-power switching applications, such as thyristor valves in a high-voltage direct current converter, can use 4H-SiC. The numerical simulation of the 4H-SiC devices requires specialized models and parameters. Here, we present a numerical simulation of the 4H-SiC thyristor on an N+ substrate gate current during the turn-on process. The base-emitter current of the PNP bipolar junction transistor (BJT) flow by adjusting the gate potential. This current eventually activated a regenerative action of the thyristor. The increase of the gate current from P+ anode to N+ gate also decreased the snapback voltage and forward voltage drop (Vf). When the doping concentration of the P-drift region increased, Vf decreased due to the reduced resistance of a low P-drift doping. An increase in the P buffer doping concentration increased Vf owing to enhanced recombination at the base of the NPN BJT. There is a tradeoff between the breakdown voltage and forward characteristics. The breakdown voltage is increased with a decrease in concentration, and an increase in drift layer thickness occurs due to the extended depletion region and reduced peak electric field.

Simulation, Fabrication and Characterization of 4H-SiC Floating Junction Schottky Barrier Diodes (Super-SBDs)

2007 ◽  
Vol 556-557 ◽  
pp. 881-884 ◽  
Author(s):  
Chiharu Ota ◽  
Johji Nishio ◽  
Tetsuo Hatakeyama ◽  
Takashi Shinohe ◽  
Kazutoshi Kojima ◽  
...  
Keyword(s):  
Schottky Barrier ◽  
Breakdown Voltage ◽  
Figure Of Merit ◽  
Device Simulation ◽  
Schottky Barrier Diodes ◽  
World Record ◽  
Device Structure ◽  
The World ◽  
Fabrication And Characterization

The calculation for 4H-SiC floating junction Schottky barrier diodes (Super-SBDs) was carried out by device simulation and the optimized device structure was fabricated. The best characteristics of the Super-SBDs were breakdown voltage of 2700V and the specific on-resistance of 2.57m*cm2. The world record of Bariga’s Figure of Merit (BFOM) for SiC-SBD expressed by 4Vbd 2/Ron was improved to 11,354MW/cm2.

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