scholarly journals Mobility Models Based on Forward Current-Voltage Characteristics of P-type Pseudo-Vertical Diamond Schottky Barrier Diodes

Micromachines ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 598
Author(s):  
Min-Woo Ha ◽  
Ogyun Seok ◽  
Hojun Lee ◽  
Hyun Ho Lee
Keyword(s):  
Schottky Barrier ◽  
Breakdown Voltage ◽  
Doping Concentration ◽  
Voltage Drop ◽  
Mobility Model ◽  
Mobility Models ◽  
Schottky Barrier Diodes ◽  
Forward Voltage ◽  
Forward Voltage Drop ◽  
P Type

Compared with silicon and silicon carbide, diamond has superior material parameters and is therefore suitable for power switching devices. Numerical simulation is important for predicting the electric characteristics of diamond devices before fabrication. Here, we present numerical simulations of p-type diamond pseudo-vertical Schottky barrier diodes using various mobility models. The constant mobility model, based on the parameter μconst, fixed the hole mobility absolutely. The analytic mobility model resulted in temperature- and doping concentration-dependent mobility. An improved model, the Lombard concentration, voltage, and temperature (CVT) mobility model, considered electric field-dependent mobility in addition to temperature and doping concentration. The forward voltage drop at 100 A/cm2 using the analytic and Lombard CVT mobility models was 2.86 and 5.17 V at 300 K, respectively. Finally, we used an empirical mobility model based on experimental results from the literature. We also compared the forward voltage drop and breakdown voltage of the devices, according to variations in p- drift layer thickness and cathode length. The device successfully achieved a low specific on-resistance of 6.8 mΩ∙cm2, a high breakdown voltage of 1190 V, and a high figure-of-merit of 210 MW/cm2.

Temperature-Dependent Characteristics of 4H-SiC Buried Grid JBS Diodes

2015 ◽  
Vol 821-823 ◽  
pp. 600-603 ◽  
Author(s):  
Jang Kwon Lim ◽  
S.A. Reshanov ◽  
Wlodek Kaplan ◽  
A. Zhang ◽  
Tomas Hjort ◽  
...  
Keyword(s):  
Leakage Current ◽  
Doping Concentration ◽  
Voltage Drop ◽  
Schottky Contact ◽  
Drift Region ◽  
Forward Voltage ◽  
Forward Voltage Drop ◽  
Increasing Temperature ◽  
P Type ◽  
State Resistance

4H-SiC Schottky Barrier Diodes (SBD) have been developed using p-type buried grids (BGs) formed by Al implantation. In order to reduce on-state resistance and improve forward conduction, the doping concentration of the channel region between the buried grids was increased. The fabricated diodes were encapsulated with TO-254 packages and electrically evaluated. Experimental forward and reverse characteristics were measured in the temperature range from 25 °C to 250 °C. On bare die level, the forward voltage drop was reduced from 5.36 V to 3.90 V at 20 A as the channel doping concentration was increased, which introduced a low channel resistance. By the encapsulation in TO-254 package, the forward voltage drop was decreased approximately 10% due to a lower contact resistance. The on-state resistance of the identical device measured on bare die and in TO-254 package increased with increasing temperature due to the decreased electron mobility in the drift region resulting in higher resistance. The incremental contact resistances of the bare dies were larger than in the packaged devices. One key issue associated with conventional Junction Barrier Schottky (JBS) diodes is a high leakage current at high temperature operation over 200 °C. The developed Buried Grid JBS (BG JBS) diode has significantly reduced leakage current due to a better field shielding at the Schottky contact. The leakage current of the packaged BG JBS diodes is compared to pure SBD and commercial JBS diodes.

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.

10 kV, 10 A Bipolar Junction Transistors and Darlington Transistors on 4H-SiC

2010 ◽  
Vol 645-648 ◽  
pp. 1025-1028 ◽  
Author(s):  
Qing Chun Jon Zhang ◽  
Robert Callanan ◽  
Anant K. Agarwal ◽  
Albert A. Burk ◽  
Michael J. O'Loughlin ◽  
...  
Keyword(s):  
Breakdown Voltage ◽  
Voltage Drop ◽  
Current Gain ◽  
Bipolar Junction Transistors ◽  
Collector Current ◽  
Forward Voltage ◽  
Collector Voltage ◽  
Forward Voltage Drop ◽  
Chip Size ◽  
Dc Current

4H-SiC Bipolar Junction Transistors (BJTs) and hybrid Darlington Transistors with 10 kV/10 A capability have been demonstrated for the first time. The SiC BJT (chip size: 0.75 cm2 with an active area of 0.336 cm2) conducts a collector current of 10 A (~ 30 A/cm2) with a forward voltage drop of 4.0 V (forced current gain βforced: 20) corresponding to a specific on-resistance of ~ 130 mΩ•cm2 at 25°C. The DC current gain, β, at a collector voltage of 15 V is measured to be 28 at a base current of 1 A. Both open emitter breakdown voltage (BVCBO) and open base breakdown voltage (BVCEO) of ~10 kV have been achieved. The 10 kV SiC Darlington transistor pair consists of a 10 A SiC BJT as the output device and a 1 A SiC BJT as the driver. The forward voltage drop of 4.5 V is measured at 10 A of collector current. The DC forced current gain at the collector voltage of 5.0 V was measured to be 440 at room temperature.

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.

The Impact of Schottky Barrier Tunneling on SiC-JBS Performance

2009 ◽  
Vol 615-617 ◽  
pp. 667-670 ◽  
Author(s):  
Gary M. Dolny ◽  
Richard L. Woodin ◽  
T. Witt ◽  
J. Shovlin
Keyword(s):  
Electric Field ◽  
Breakdown Voltage ◽  
Voltage Drop ◽  
Forward Voltage ◽  
Trade Off ◽  
Practical Applications ◽  
Forward Voltage Drop ◽  
Surface Electric Field ◽  
The Impact ◽  
Barrier Tunneling

The impact of barrier tunneling on SiC-JBS performance is studied both experimentally and theoretically. We show that although the pinch-off effects associated with the JBS structure can significantly suppress the surface electric field, barrier tunneling still dominates the reverse behavior. Barrier tunneling determines the apparent breakdown voltage, as well as the apparent breakdown voltage vs. forward voltage drop trade-off of the JBS diode in practical applications.

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.

Influence of Trench Design on the Electrical Properties of 650V 4H-SiC JBS Diodes

2019 ◽  
Vol 963 ◽  
pp. 549-552
Author(s):  
Oleg Rusch ◽  
Jonathan Moult ◽  
Tobias Erlbacher
Keyword(s):  
Electrical Properties ◽  
Leakage Current ◽  
Breakdown Voltage ◽  
Voltage Drop ◽  
Electrical Characteristics ◽  
Electrical Field ◽  
Forward Voltage ◽  
Voltage Drops ◽  
Forward Voltage Drop ◽  
Trench Structure

This work presents a design study of customized p+ arrays having influence on the electrical properties of manufactured 4H-SiC Junction Barrier Schottky (JBS) diodes with designated electrical characteristics of 5 A forward and 650 V blocking capabilities. The effect of the Schottky area consuming p+ grid on the forward voltage drop, the leakage current and therefore the breakdown voltage was investigated. A recessed p+ implantation, realized through trench etching before implanting the bottom of the trenches, results in a more effective shielding of the electrical field at the Schottky interface and therefore reduces the leakage current. Customizing the p+ grid array in combination with the trench structure, various JBS diode variants with active areas of 1.69 mm2 were fabricated whereas forward voltage drops of 1.58 V @ 5 A with blocking capabilities up to 1 kV were achieved.

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.

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