How can a cutting-edge gallium nitride high-electron-mobility transistor encounter catastrophic failure within the acceptable temperature range

Research output: Contribution to journalJournal article


Commercial gallium nitride (GaN) high-electron-mobility transistors (HEMT) used for power electronics applications shows superior performance compared to silicon (Si) -based transistors. Combined with an increased radiation hardening properties they are key candidates for high-performance power systems in a harsh environment such as space. However, for this purpose, it is key to know the potential failure mechanisms of the devices in depth. Here, we demonstrate how the repeated thermomechanical stress in a power cycling test within specified operating conditions destroys the gallium nitride device. Based on leakage current localization analysis, we identify a failure mechanism with a yet unknown root cause. Utilizing emission microscopy, focused ion beam cutting, scanning electron microscope techniques, it is revealed that multi-layer cracks of a gallium nitride die triggered by a commercial leading package structure, which shows excellent capability, under frequent thermomechanical stress. Through Multiphysics simulations, it is shown that the structural factors that lie behind the strong performing component properties inside the package ultimately are directly related to the failure pattern.
Original languageEnglish
JournalI E E E Transactions on Power Electronics
Publication statusE-pub ahead of print - 2020



  • Gallium nitride
  • Temperature measurement
  • Photonics
  • Failure analysis
  • Power electronics
  • Silicon
  • Transistors

Cite this