Experimental study of the mechanisms and defects of single event leakage induced by high-energy heavy ions in AlGaN/GaN diodes

Gallium nitride (GaN) is a promising material for next-generation space microelectronics, demonstrating considerable reliability under low-energy irradiation compared to conventional semiconductors. However, under high-energy irradiation, GaN suffers considerably from single-event effects, where a single heavy-ion strike can cause anomalous behavior such as a permanent increase in leakage current or even the complete destruction of the device. Despite the severity of this issue, an understanding of the physics involved remains limited and has been primarily confined to theoretical simulations. In this study, we investigated the I–V characteristics of AlGaN/GaN diodes affected by single-event leakage current. The analysis shows the increase in forward leakage current originates from a small, localized region in the AlGaN barrier described by a parallel diodes model, while the increase in reverse leakage arises from trap-assisted tunneling in the same damaged region. Transmission electron microscopy imaging confirmed a highly defective AlGaN barrier localized near the anode edge.