Power Cycling Results of Discrete Gallium Nitride Gate Injection Transistors

The reliability of discrete GaN Gate Injection Transistors (GIT) in power cycling tests (PCT) was evaluated. The investigation in this paper reveal that discrete GaN GITs achieved several times the lifetime expected by discrete power device lifetime model for Si IGBTs [1]. The large number of Au nailhead bonds, which are placed at the edge of the chip, combined with a strong lateral temperature gradient on chip level can explain this. The power cycling was also a long-time stress of the gate with DC gate current in combination with a cycling drain current. No significant change in parameters was found.