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

In this article, we demonstrate that a physics-based compact model can facilitate to analyze the reliability using an example of γ-ray induced instability in AlGaN/GaN HEMTs. First, the typical AlGaN/GaN HEMTs are subjected to the cumulative γ-ray irradiation, exhibiting the drain current (ID) increase. In order to further elucidation, the root cause, the compact model is implemented and calibrated with the pristine case. Then, ID-VG and ID-VD characteristics subjected to the γ-ray irradiation are fitted with the compact model. The extracted μ and Rc 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 μ (Rc is fixed as the pristine case) and 2) fitted Rc (μ is fixed as the pristine case), the shift of μ is identified as the root cause leading to the ID 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.