Understanding gamma-Ray Induced Instability in AlGaN/GaN HEMTs Using a Physics-Based Compact Model

In this article, we demonstrate that a physics-based compactmodel can facilitate to analyze the reliability using an example of gamma-ray induced instability in AlGaN/GaN HEMTs. First, the typical AlGaN/GaN HEMTs are subjected to the cumulative gamma-ray irradiation, exhibiting the drain current (I-D) increase. In order to further elucidation, the root cause, the compact model is implemented and calibrated with the pristine case. Then, I-D-V-G and I-D-V-D characteristics subjected to the gamma-ray irradiation are fitted with the compact model. The extracted mu and R-c are consistent with the results obtained by the Hall measurement and circular transmission line measurement (C-TLM). By comparing the fitted curves with considering: 1) fitted mu (R-c is fixed as the pristine case) and 2) fitted R-c (mu is fixed as the pristine case), the shift of mu is identified as the root cause leading to the I-D increase because of the better fitting results. Therefore, with the assistance of the physics-based compact model, the shift of the parameter can be further analyzed to understand the origin of the instability.