The Impact of Radiation-Induced FeGa– VN Defects on the Electrical Performance of AlGaN/GaN HEMTs

Abstract

In this article, a combined approach of experimentation and simulation is adopted to study the effects of radiation-induced defects on the electrical properties of GaN high-electron-mobility transistors (HEMTs) under 6-MeV chlorine ion irradiation. Through electrical performance and current deep-level transient spectroscopy (I-DLTS) testing, the evolution of defect from ${V} _{\text {N}}$ – ${V} _{\text {N}}$ (+1/+2) and FeGa to FeGa– ${V} _{\text {N}}$ is observed with increasing irradiation fluence. When the fluence exceeds $5\times 10^{10}$ ions/cm2, the concentration of FeGa– ${V} _{\text {N}}$ defects reaches saturation due to the limitation of the FeGa concentration, which is reflected in the changes to the peak ${G} _{M}$ . The FeGa– ${V} _{\text {N}}$ defect is confirmed as a primary factor contributing to electrical degradation in the 2-D electron gas (2DEG) conductivity of the GaN-HEMTs.