Short Circuits in GaN HEMTs: Test Bench Setup and Characterization

In this article, a setup to characterize the failure mechanisms and degradation indicators of gallium nitride (GaN) high-electron-mobility transistors (HEMTs) under short-circuit events is presented. Understanding how this technology fails is critical, especially for space applications where a common failure mechanism is the short-circuit event due to radiation. First, the previous literature in the field is reviewed. Both the behavior under single and repetitive short circuits and failure mechanisms are discussed. Then, a systematic method is proposed to measure the critical electrical parameters and analyze the behavior of the device under test under short-circuit failure to build a reliability model. A setup to characterize GaN HEMT devices is developed, and using it, multiple tests and short circuits have been performed to characterize the devices under test at different conditions and to identify critical parameters and aging indicators. The reliability challenge of GaN devices could be addressed by having on-board in-system prognostics and device health monitoring techniques to predict device failures well ahead of time.