Degradation of AlInN/AlN/GaN High Electron Mobility Transistors under Proton Irradiation

We measured the effects of 3-MeV proton irradiation on AlInN/AlIn/GaN HEMTs. After fluences larger or equal to 1013 p/cm2, the devices experience threshold voltage shifts and transconductance degradation, visible both in DC and pulsed measurements, within the range of the observed degradation in conventional GaN HEMTs. Some differences in the post-rad response are visible between the two types of tested devices, likely due to a different initial concentration of defects. Source field plates are shown to have a very limited impact on the radiation response.