Physical Model of Trapping-Induced Dynamic Degradation in GaN HEMT

This paper demonstrates the experimental procedure and a physical model to understand the dynamic degradation process of GaN-based high electron mobility transistor under the influence of hot carrier injection and charger trapping. Charge trapping can significantly alter the local electric field, degrade the performance of GaN devices as well as their reliability, and eventually lead to device failure. To investigate the underlying mechanism of this phenomenon, we stress the device under hard switching condition to induce severe charge trapping and measure the behavior of dynamic Rdson over time. Based on the data, we propose a physical model to provide a quantitative explanation of dynamic degradation to predict the operation lifetime of GaN devices.