Design and implementation of a non-destructive test circuit for SiC-MOSFETs

Silicon carbide(SiC) power devices have been developed and they are sold in markets. Many papers have dealt with inverter circuits that use SiC power devices to improving efficiency and realize high power density converters. However, the power converters that use SiC power devices have not become commercially available, because the reliability of the SiC-MOSFET under switching-operation has not been sufficiently discussed. This paper presents a non-destructive test circuit for SiC-MOSFETs, and the experimental results have confirmed the validity of the non-destructive test circuit for Si- and SiC-MOSFETs. Moreover, the experimental results presents the phenomenon just before destruction of the MOSFETs. The purpose of the non-destructive test circuit is to evaluate the extreme conditions under actual switching operation without the destruction of the power devices. This paper shows experimental results under short-circuit tests for Si super junction MOSFETs (SJ-MOSFETs), and SiC double-diffusion MOSFETs (DMOSFETs). These experimental results will be analyzed to improve the reliability of SiC power device. As a result, the short-circuit switching operation of the SiC-MOSFET is observed to be different from that of the Si-MOSFET.