Cryogenic Static and Dynamic Characterizations of 650 V Field Stop Trench Si IGBT

Cryogenic power conversion is advantageous in various applications. To enable the future cryogenic power electronics, the performance of power devices under cryogenic temperature should be investigated. In this article, the cryogenic static and dynamic characterizations for a 650 V field stop trench silicon (Si) insulated gate bipolar transistor (IGBT) are performed. The device forward voltage drops with the decrease of temperature, which is beneficial for the conduction loss reduction. However, the forward voltage drop starts increasing when the temperature is further decreased due to the carrier freeze out. The device threshold voltage and transconductance increase with the decrease of temperature. For the dynamic performance, the device turn-off switching speed is improved significantly under low temperatures when compared with room temperature, the associated long tail current phenomenon at room temperature can be alleviated, which enables higher switching frequency operation. The device dynamic forward voltage is also measured under different temperatures by means of a voltage clamping circuit. The device forward voltage decreases with the decrease of temperature. Overall, the evaluated device is a promising candidate for low temperature operations and the optimal operating temperature is around 143 K to 100 K. In addition, the gate driver circuitries are suggested not to operate as the same temperature as the power device owning to their malfunctions at cryogenic temperatures.