Study of short-circuit robustness of p-GaN and cascode transistors

Short-circuit (SC) robustness is necessary for GaN adoption in industrial applications but continued efforts are needed to make them ready for real-world use. This work presents the results of >160 destructive tests performed on commercially available 600 V and 650 V GaN HEMT transistors from four different manufacturers with different structures (p-GaN and cascode). Under a DC-bus voltage of 400 V, the robustness is strongly dispersed: the Time To Failure (TTF) varies from hundreds of nanoseconds to hundreds of microseconds. But at a lower voltage (270 V), the TTF is generally in the millisecond range.