Analysis on reverse recovery characteristic of SiC MOSFET intrinsic diode

摘要

Different from IGBT, SiC MOSFET can operate as synchronous rectifier with low on resistance, thus the intrinsic diode only work during the dead time. To utilize the intrinsic diode as freewheeling diode, the reverse recovery characteristic is analyzed and discussed in this paper. Four operating conditions, i.e. turn-off voltage, forward current, current commutating slope and junction temperature, are considered to evaluate the turn-off performance of SiC MOSFET intrinsic diode. To test the device and minimize the stray inductance, a double pulse test bench based on direct bond copper substrate and bare dies is designed. The reverse recovery feature of two kinds of silicon p-i-n diode is also tested for comparison. The experimental results show that the intrinsic diode is sensitive to the junction temperature and the performance gets worse at high temperature, but still much better than silicon p-i-n diode.