Proton-irradiation effects on AlGaN/AlN/GaN high electron mobility transistors

The degradation of AlGaN/AlN/GaN high electron mobility transistors due to 1.8-MeV proton irradiation was measured at fluences up to 3*10^15 cm^-2. The devices have much higher mobility than AlGaN/GaN devices, but they possess similarly high radiation tolerance, exhibiting little degradation at fluences up to 1*10^14 cm^-2. Decreased sheet carrier mobility due to increased carrier scattering and decreased sheet carrier density due to carrier removal are the primary damage mechanisms. The device degradation is observed as a decrease in the maximum transconductance, an increase in the threshold voltage, and a decrease in the drain saturation current.