Electrothermal Interaction Mechanism for SiC Power MOSFET in Linear-Mode Operation From 25°C to 375°C: Theoretical Analysis, Experimental Verification and Packaging Effect

1 Abstract-The high-temperature capability of power devices is one of the effective ways to enhance the power density of converters. Thermal runaway is an acknowledged issue associated with high-temperature operation, typically occurring in industrial applications of Si power MOSFETs under linear mode operation (LMO). However, the occurrence of this runaway in SiC applications remains unclear. This paper, for the first time, investigates the electrothermal interaction of SiC power MOSFETs in LMO across a wide junction temperature range (25°C to 375°C). A formula describing the electrothermal interaction mechanism of LMO is developed and validated through semiconductor physics simulations and experimental results. Additionally, a comparative study of the device’s high-temperature conversion capabilities, influenced by packaging parameters, is conducted. A control method for thermal sensitivity is also introduced, demonstrating significant potential for high-sensitivity junction temperature detection. This research offers a deeper understanding of the electrothermal interactions of SiC power MOSFETs in LMO across a broad temperature range and provides fundamental insights and guidance for high- and ultra-high-temperature SiC applications.