TID Characterization of COTS HEMT GaN Transistors: An In Situ Study of Static and Dynamic Parameters up to 100 krad of Co-60 Gamma Radiation

Gallium nitride (GaN) technology has emerged as a transformative solution in the semiconductor industry due to its exceptional performance in high-power and high-frequency applications. With its inherent radiation resilience, GaN is particularly suited for environments such as space electronics and nuclear instrumentation. While static parameter testing under radiation has been extensively studied, dynamic parameter degradation—including propagation delays, rise/fall times, and efficiency losses—remains underexplored. These dynamic characteristics are useful for applications requiring precise timing, signal integrity, and rapid response, such as satellite communication and nuclear systems. This study evaluates the radiation resilience of three commercially available GaN transistors during a 100-krad (Si) Co-60 gamma irradiation campaign, with a focus on both static and dynamic parameters. Static parameters, such as threshold voltage and on-state resistance, exhibited minimal degradation, while a larger change was observed in gate current. In contrast, dynamic parameters revealed smaller changes, including faster propagation delays and reduced efficiency, with variability observed across device types. The findings support a device-specific co-design of transistors and driver electronics for radiation-tolerant power stages.