Abstract
The effects of proton irradiation energy on dc, small signal, and large signal rf characteristics of
AlGaN/GaN high electron mobility transistors (HEMTs) were investigated. AlGaN/GaN HEMTs
were irradiated with protons at fixed fluence of 51015/cm2 and energies of 5, 10, and 15 MeV.
Both dc and rf characteristics revealed more degradation at lower irradiation energy, with
reductions of maximum transconductance of 11%, 22%, and 38%, and decreases in drain saturation
current of 10%, 24%, and 46% for HEMTs exposed to 15, 10, and 5MeV protons, respectively.
The increase in device degradation with decreasing proton energy is due to the increase in linear
energy transfer and corresponding increase in nonionizing energy loss with decreasing proton
energy in the active region of the HEMTs. After irradiation, both subthreshold drain leakage
current and reverse gate current decreased more than 1 order of magnitude for all samples. The
carrier removal rate was in the range 121–336 cm1 over the range of proton energies employed in
this study
