Influence of donor-type hole traps under p-GaN gate in GaN-based gate injection transistor (GIT)

Anomalous turn off (ATO) is observed for the GaN-based normally-off Gate Injection Transistor (GIT) with a threshold voltage having smaller than 0.7 V. On the other hand, ATO is not observed for the GIT with a threshold voltage larger than 0.7 V. The commercialized GITs are free from the ATO, because their threshold voltages are controlled to be 1.2 +/- 0.3 V, which is larger than 0.7 V. Device simulation study indicates that a donor-type hole trap is responsible for the ATO, because the internal electric field is large enough to induce the emission of the captured hole traps that are made when the device is turned off. It is simulated that the specified donor-type hole traps influence minor effects on the switching behavior.