Low-Fluence Neutron Irradiation Effects on AlGaN/GaN HEMTs

AlGaN/GaN-based high electron mobility transistors (HEMTs) are ideal candidates for power electronics in consumer, industrial, and space applications. Attributed to their excellent performance in electrical output and chemical stability, AlGaN/GaN HEMTs enable tolerant neutron irradiation in harsh environments. Different from high-fluence irradiation-induced device failure, the investigation of low-fluence neutron irradiation is of great significance to understand the early damage mechanism of HEMTs. Here, the modulated electrical properties are presented of AlGaN/GaN HEMTs under low-fluence neutron irradiations of 4.5 × 10¹³ and 6.0 × 10¹³ cm⁻². After irradiation, the electrical characteristics of the samples are carefully measured, the output performance of different irradiated devices shows a similar change trend, i.e., almost no changes or only decreased slightly (≤14%) near the knee voltage. For leakage current, the samples irradiated with different fluences show different characteristics, including a slight decrease with the fluence of 4.5 × 10¹³ cm⁻², and a slight increase with the fluence of 6.0 × 10¹³ cm⁻². To further investigate the internal mechanisms, the performance changes are also simulated of the device by using Crosslight software. According to the measurements, it is concluded that the low-fluence neutron irradiation will initially affect the 2DEG mobility and the surface states of the HEMTs.