scholarly journals Characterization of high-voltage high-speed switching power semiconductors for high frequency cryogenically-cooled application

2017 ◽  
Author(s):  
Zheyu Zhang ◽  
Craig Timms ◽  
Jingyi Tang ◽  
Ruirui Chen ◽  
Jordan Sangid ◽  
...  
Keyword(s):  
High Voltage ◽  
High Frequency ◽  
High Speed ◽  
Power Semiconductors ◽  
Switching Power ◽  
High Speed Switching

4H-SIC Dmosfets for High Frequency Power Switching Applications

2003 ◽  
Vol 764 ◽  
Author(s):  
Sei-Hyung Ryu ◽  
Anant K. Agarwal ◽  
James Richmond ◽  
John W. Palmour
Keyword(s):  
High Voltage ◽  
High Speed ◽  
High Performance ◽  
High Frequency Power ◽  
Power Devices ◽  
Power Switching ◽  
High Speed Switching ◽  
Unipolar Devices ◽  
Very High ◽  
Frequency Power

AbstractVery high critical field, reasonable bulk electron mobility, and high thermal conductivity make 4H-Silicon carbide very attractive for high voltage power devices. These advantages make high performance unipolar switching devices with blocking voltages greater than 1 kV possible in 4H-SiC. Several exploratory devices, such as vertical MOSFETs and JFETs, have been reported in SiC. However, most of the previous works were focused on high voltage aspects of the devices, and the high speed switching aspects of the SiC unipolar devices were largely neglected. In this paper, we report on the static and dynamic characteristics of our 4H-SiC DMOSFETs. A simple model of the on-state characteristics of 4H-SiC DMOSFETs is also presented.

scholarly journals Terahertz time-domain ellipsometry with high precision for the evaluation of GaN crystals with carrier densities up to 1020 cm−3

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Verdad C. Agulto ◽  
Toshiyuki Iwamoto ◽  
Hideaki Kitahara ◽  
Kazuhiro Toya ◽  
Valynn Katrine Mag-usara ◽  
...  
Keyword(s):  
Electrical Properties ◽  
High Voltage ◽  
Time Domain ◽  
High Frequency ◽  
Carrier Density ◽  
Power Devices ◽  
Reflection Configuration ◽  
Nondestructive Characterization ◽  
Thz Waves

AbstractGallium nitride (GaN) is one of the most technologically important semiconductors and a fundamental component in many optoelectronic and power devices. Low-resistivity GaN wafers are in demand and actively being developed to improve the performance of vertical GaN power devices necessary for high-voltage and high-frequency applications. For the development of GaN devices, nondestructive characterization of electrical properties particularly for carrier densities in the order of 1019 cm−3 or higher is highly favorable. In this study, we investigated GaN single crystals with different carrier densities of up to 1020 cm−3 using THz time-domain ellipsometry in reflection configuration. The p- and s-polarized THz waves reflected off the GaN samples are measured and then corrected based on the analysis of multiple waveforms measured with a rotating analyzer. We show that performing such analysis leads to a ten times higher precision than by merely measuring the polarization components. As a result, the carrier density and mobility parameters can be unambiguously determined even at high conductivities.

Characterization of Electric Discharge Machining for Silicon Carbide Single Crystal

2008 ◽  
Vol 600-603 ◽  
pp. 855-858 ◽  
Author(s):  
Tomohisa Kato ◽  
Toshiya Noro ◽  
Hideaki Takahashi ◽  
Satarou Yamaguchi ◽  
Kazuo Arai
Keyword(s):  
Silicon Carbide ◽  
High Temperature ◽  
Electric Discharge ◽  
High Voltage ◽  
High Speed ◽  
Surface Damage ◽  
Lower Surface ◽  
Etch Pits ◽  
Electric Discharge Machining

In this study, we report electric discharge machining (EDM) as a new cutting method for silicon carbide (SiC) single crystals. Moreover, we discuss characteristics and usefulness of the EDM for the SiC. The EDM realized not only high speed and smooth cutting but also lower surface damage. Defect propagation in the EDM SiCs have been also estimated by etch pits observation using molten KOH, however, we confirmed the EDM has caused no damage inside the SiCs in spite of high voltage and high temperature during the machining.

950V, 8.7mohm-cm2 High Speed 4H-SiC Power DMOSFETs

2006 ◽  
Vol 911 ◽  
Author(s):  
Sei-Hyung Ryu ◽  
Charlotte Jonas ◽  
Bradley Heath ◽  
James Richmond ◽  
Anant Agarwal ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
High Voltage ◽  
High Speed ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Blocking Voltage ◽  
Layer Resistance ◽  
High Speed Switching ◽  
Device Operation ◽  
Drift Layer

AbstractFabrication and characteristics of high voltage, high speed DMOSFETs in 4H-SiC are presented. The devices were built on 1.2×1016 cm-3 doped, 6 mm thick n-type epilayer grown on a n+ 4H-SiC substrate. A specific on-resistance of 8.7 mW-cm2 and a blocking voltage of 950 V were measured. Device characteristics were measured for temperatures up to 300oC. An increase of specific on-resistance by 35% observed at 300oC, when compared to the value at room temperature. This is due to a negative shift in MOS threshold voltage, which decreases the MOS channel resistance at elevated temperatures. This effect cancels out the increase in drift layer resistance due to a decrease in bulk electron mobility at elevated temperature, resulting in a temperature stable on-resistance. The device operation at temperatures up to 300 oC and high speed switching results are also reported in this paper.

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