SiC power devices are becoming widely used in the manypower electronic conversion systems, especially at highpower 1-3. The Si devices were first introduced to enablethe power conversion systems to operate at higher powerdensity as well as the higher frequency. Although, Si powerdevices succeeded to reach this goal, its utilizations wasrestricted to some applications due to its conduction andswitching losses.
The losses are due to the special materialproperty of Si 4. On the other hand, SiC devices weredeveloped to overcome the limitations of Si devices. Thebreakdown electric field of SiC is about ten times higher thanthat of Si. This characteristic enables the device to makethinner voltage blocking layer, which results in lowerconduction loss 5-8. Moreover SiC has wide band-gapwhich enable them to operate the device at high temperatures.In addition, these devices have high thermal conductivitywhich makes it able to spread the heat much easier than itscorresponding Si device with the same power handlingcapability. The lower resistance of SiC makes it possible torealize high voltage switching with sufficiently lowconduction loss. These advantages makes possible for the SiCdevice to operate at high switching frequency for high voltageapplication circuits.
For circuit designers to fully utilize the advantages of SiCpower device technologies, compact models are needed, toaccurately present the thermal behavior of the device as wellas its electrical characteristics 1-7. The main objective ofthis paper is to develop a new model, to predict the electrothermal behavior of the SiC power switching devices. Thepresented coupled electro-thermal IGBT model is developedbased on the Kraus/Elmore model. The main feature of thismodel is its ability to consider the variation of dynamicperformance with respect to self-heating effects andprediction of the temperature dependent characteristics of theIGBT. The model is used to describe the performance of a1200V, 100A, 4HSiC IGBT.In this work, initially, the proposed electro-thermal modelof the device is described and the obtained results arecompared with experimental data. The effects of temperaturerise on the high frequency phenomenon during the switchingactions of the device are evaluated as well as the power lossof the device.
We have verified that a detailed SiC IGBTmodel is capable of accurately describing the static anddynamic electro-thermal performance of the device.