Effect of Heavy Ion Radiation on Electrical Performance of AlGaN/GaN HEMTs in Non-Gate Region

This study employs different types and energies of heavy ions to irradiate AlGaN/GaN high electron mobility transistors (HEMTs), inducing defects with a non-uniform depth distribution in the GaN epitaxial layer beneath the non-gate region. By integrating experimental and simulation approaches, we investigate the variation patterns of the device's electrical performance as a function of irradiation fluence. Through electrical performance testing and simulations using extreme-environment radiation effect technology computer aided design (ERETCAD) software, it was observed that heavy ion-induced damage is confined to the GaN epitaxial layer beneath the non-gate region, the saturated drain current (Ids) decreases with increasing irradiation fluence, and the threshold voltage (Vth) of the device remains unchanged. Heavy ion radiation introduces displacement defects in the GaN layer, and as the distance from the 2-D electron gas (2DEG) increases, the Coulomb scattering effect of these defects on carriers diminishes. Consequently, by accounting for the scattering effects of radiation-induced charged defects on carriers, the traditional non-ionizing energy loss (NIEL) value is refined. This adjustment leads to an equivalent degradation phenomenon where the Ids under different heavy ion irradiations correlates with the total effective non-ionizing energy deposition (TNIDeffective).