S. Ogata

4H-SiC high power SIJFET module

5kV high power full SiC module technology was developed and 1.6kV 40A SIJFET module was fabricated for the first time, which is the pressure contact flat package type and includes four 6mm /spl times/ 6mm SiC SIJFETs in addition to one 6mm /spl times/ 6mm SiC fly wheeling pn diode. SiC SIJFET operates as the bipolar transistor and its current gain ranges from 20 to 4000. Its turn-on time and turn-off time are 360ns and 109 ns respectively. Since the SIJFET module has not only high current gains but also high switching speeds, it is suitable for the low loss power conversion circuits.

3 kV 600 A 4H-SiC high temperature diode module

A 3 kV 600 A 4H-SiC high temperature diode module has been developed for use in electricity supply applications, which utilizes a pressure contact flat package type module and includes five 6 mm/spl times/6 mm SiC diode chips. The diode module does not get oxidized in the air even at 500/spl deg/C and has excellent electrical performances at high temperature.

Reliability investigation of SiC bipolar device module in long time inverter operation

The reliability of SiC bipolar device modules consisting of SiC commutated gate turn-off thyristors and SiC pin diodes fabricated on a 4° off-cut SiC substrate is investigated. According to three-phase inverter operation using a Back to Back system at DC bus voltage of 2 kV and effective output power of approximately 120 kW, the SiC module could achieve the worlds first successful inverter operation lasting more than 1000 hours, thereby verifying its reliability in long time inverter operation.

Development of a 100 kVA SiC inverter with high overload capability of 300 kVA

High overload inverters were developed by using SiC devices for the first time, although its realization by using Si devices had been difficult because of Sis low maximum Tj. The newly developed 100 kVA overload SiC inverter provides an overload capability rate of 200 % and can supply 300 kVA for up to 3 seconds. Moreover, the volume was downsized to 1/7.5 of the previous inverter and the 150 hour continuous inverter operation test at 110 kVA was performed successfully.

4.5 kV 1000 A Class SiC pn Diode Modules with Resin Mold Package and Ceramic Flat Package

4.5 kV 1000 A class high heat resistive SiC pn diode modules of both a resin mold package type using a new mold resin, Nanotec-resin KA 500, and a ceramic flat package type using a new ACTSG technique were developed for the first time. The resin mold module has a much smaller trr and Qrr in addition to higher Tj (max) of 300 degC as compared with Si pn diodes.

5kV class 4H-SiC PiN diode with low voltage overshoot during forward recovery for high frequency inverter

Forward recovery characteristics have been reported in a 5 kV class SiC pin diode used for a high frequency inverter. The 5 kV class SiC pin diode obviously has low forward voltage overshoot and an extremely small voltage shift along with a higher forward current increase rate or junction temperature as compared to the Si fast diode. The minority carrier lifetime has also been evaluated from the forward recovery characteristics, and its dependence on temperature has been investigated. Next, the relation between the minority carrier lifetime and the forward voltage drop were investigated. Even at a higher junction temperature, it was confirmed that the calculated relations between the drift region thickness and the ambipolar diffusion length approximated the best values to maintain low forward voltage drop.

Dynamic characteristics of large current capacity module using 16-kV ultrahigh voltage SiC flip-type n-channel IE-IGBT

4H-SiC carbon face flip-type n-channel implantation and epitaxial (IE)-IGBT with an epitaxial p++ substrate was developed and its switching test was carried out. We were able to achieve an ultrahigh blocking voltage greater than 16 kV, extremely low Von (6.35 V at 20 A), and good temperature stability. The switching operation was achieved by connecting three IGBTs in parallel, with a total ICE of 60 A and VCE 5 kV. The turn-off loss and turn-on loss were about 220 mJ and 120 mJ, respectively at room temperature. They show low switching loss of ultrahigh voltage SiC IE-IGBT and the possibility of large scale module with parallel connection.

180kVA Three Phase SiCGT Inverter Utilizing Novel VF Degradation Reduction Phenomena for SiC Devices

A novel phenomena of VF degradation reduction, TEDREC phenomena, was found, which can reduce the degradation by increasing SiC device temperature. To realize safe and repeatable operation of degraded SiC devices and to achieve a drastic reduction in their cost, TEDREC method was developed by using the phenomena. A 180 kVA class SiC inverter was also developed by using the method, which is the largest one among the reported SiC inverters.

Static and dynamic performance evaluation of > 13 kV SiC p-channel IGBTs at high temperatures

To examine the effect of the device structure on the on-state voltage (Von), several types of ultrahigh-voltage 4H-SiC p-channel insulated-gate bipolar transistors (IGBTs) were fabricated. A p-channel IGBT with a retrograde charge storage layer (CSL) and an additional JFET ion implantation region exhibited the lowest Von at 200 °C. To obtain a blocking voltage (BV) greater than 13 kV, a junction termination extension (JTE)-dose dependence of the BV was also investigated. Furthermore, ampere-class p-channel IGBTs with optimized device structures were fabricated for the evaluation of the switching loss (5 kV/1 A). Although the turn-off loss increased with an increase in the temperature, the loss remained as low as less than 10 mJ up to 250 °C. This performance renders the ultrahigh-voltage 4H-SiC p-channel IGBTs suitable for high-temperature and high-power applications.

New Measurement Method of Tj of SiCGT and Its Application to a High Voltage Inverter Operating at greater than 300°C

A new measurement method of Tj (junction temperature ), TjDM, of a SiC device installed and operated in a circuit is proposed. Tj of a SiC device has been related to the turn-off waveforms and estimated by the time in the turn-off process. TjS of developed SiCGTs ( SiC Commutated Gate turn-off Thyristors ) under the high voltage half bridge inverter operation at 2 kHz are measured, and are confirmed to be greater than 300degC. It is demonstrated that the SiCGTs can operate in the half bridge inverter at the high voltage of 2 kV and high temperature of 315degC. Furthermore, it is shown to be able to measure real time Tj and pick up higher Tj of SiCGT compared with normal devices in the 3 phase inverter.