Study on single-event radiation effects and hardening techniques in GaN HEMTs

Abstract

We propose a new radiation-hardened AlGaN/GaN High Electron Mobility Transistor (N-HEMT) structure with an AlGaN insertion layer integrated into a conventional gate field-plate configuration. The AlGaN insertion layer acts as a back-barrier, effectively minimizing leakage current in the buffer layer, which in turn boosts the breakdown voltage of the device. Due to the band discontinuity and bandgap difference between AlGaN and GaN, this layer creates a quantum well at the heterojunction interface, trapping radiation-induced electrons and blocking their entry into the conductive channel. This mechanism lowers the production rate of electron–hole pairs triggered by impact ionization, significantly enhancing the device’s tolerance to single-event burnout (SEB). By optimizing parameters using Sentaurus TCAD, the reinforced structure (N-HEMT) attains a breakdown voltage of 912 V and an SEB threshold of 600 V, reflecting gains of 77 V and 350 V, respectively, compared to the conventional standard AlGaN/GaN HEMT structure (T-HEMT). While slight reductions in output and transfer performance are observed, these are considered insignificant for practical use.