Dispersion of Electrical Characteristics and Short-Circuit Robustness of 600 V Emode GaN Transistors

This paper presents an experimental study of the robustness of 600 V normally-off GaN High Electron Mobility Transistors (HEMT) submitted to Short-Circuits (SC) operations. The obtained results reveal a severe dispersal in terms of SC robustness: some devices were able to support SC of a very long duration but others failed immediately, for the same electrical and thermal initial constraints. In order to understand this dispersal, static characterizations and collapse-related measurements have been carried out on a large number of devices from the same manufacturer with the same blocking voltage and different current ratings. Then, destructive shortcircuits were launched on these transistors. Finally, the time leading to failure (TLF) for a given DC voltage was correlated with the parameters extracted from the characterizations.