Source Current Circulation Phenomenon and Suppression Method of High Voltage Sic Devices

The current capacity enhancement of SiC devices is the key to expanding their application scenarios, and the main method of capacity enhancement is to connect a larger number of chips in parallel inside the device. In the parallel SiC chips double pulse experiment, it was observed that the current at the source was uneven and there was a current circulation phenomenon during the device turn-off process. This article constructed an equivalent circuit that considers external circuit stray inductance. After analyzing the parasitic parameters of the equivalent circuit, this paper proposes a source current circulation suppression and current consistency enhancement method for SiC devices, which eliminates the loop current during the tailing current stage while reducing the current inconsistency by 80 %. Using this method, the device capacity has been significantly increased, newly manufactured SiC device achieves the highest 500 A continuous switching and 1000 A single pulse turn-off capability.