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

Abstract

In this article, we demonstrate that a physics-based compact model 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.