Demonstration of robust single-event and total ionizing dose tolerance in 6-in. GaN-on-sapphire HEMTs

Power devices for space applications suffer severely from single-event burnout (SEB) and total ionizing dose (TID) effects, which also pose critical challenges to dynamic switching performance and reliability. This work presents the first demonstration of a 6-in. E-mode GaN-on-sapphire HEMT simultaneously achieving robust SEB and TID hardness while maintaining circuit-level dynamic switching capability. The enhanced irradiation hardness is physically derived from the notable reduction in ion deposition energy in the thin epitaxial layers of the GaN-on-sapphire structure, as well as the insulating nature of the sapphire substrate, rather than from complex structural modifications. As a result, the device exhibits a high SEB voltage (VSEB) of 715 V under 1.3 GeV Ta ion irradiation, which remarkably outperforms conventional GaN-on-Si HEMTs that fail under a 200 V bias. Furthermore, a breakdown voltage of 755 V is achieved under γ-ray irradiation up to 7 Mrad(Si), representing the highest value reported for GaN devices to date. Moreover, by employing ultraviolet pulsed laser irradiation combined with dynamic switching circuits, nanosecond-level dynamic switching performance and over 1 × 106 cycles dynamic overvoltage robustness are demonstrated. These superior irradiation and dynamic performances, achieved by simple, cost-effective GaN-on-sapphire technology, hold great potential for high-power aerospace electronics.