Analysis of 1^st & 3^rd Quadrant Electrothermal Robustness of Symmetrical and Asymmetrical Double- Trench SiC Power MOSFETs Under UIS

Abstract

A Asymmetrical Double-trench SiC MOSFETs are discussed in terms of the reverse recovery characteristics and its impact on the avalanche ruggedness of the device, based on different failure mechanisms. The experimental measurements are performed at a wide range of switching rates and temperatures ranging from 25°C to 175°C. Two different experimental test circuits are used for the double pulse measurements of the body diode and the unclamped inductor switching experiments. The DC link voltage in UIS tests have been increased step by step till the failure of the devices. The measurements indicate that the SiC planar MOSFET has the largest reverse recovery charge among the SiC devices, only seconded to the significant reverse recovery charge of the Silicon Superjunction device. The measurements of the avalanche ruggedness indicate that the Symmetrical doubletrench SiC MOSFET is more rugged compared to other device at room temperature while the Asymmetrical double-trench SiC MOSFET is more rugged at high temperatures.

Electrothermal Power Cycling to Failure of Discrete Planar, Symmetrical Double-Trench and Asymmetrical Trench SiC MOSFETs

“…However, as replacement of the established Silicon counterparts, the robustness under extreme conditions still needs further analysis, i.e. in cases of short-circuits [4]- [6] and avalanche [7], [8], while other less severe stress conditions such as the bias temperature instability [9], [10] also need further study.…”