Abstract
The effects of proton irradiation energy on dc and rf characteristics of InAlN/GaN high electron
mobility transistors (HEMTs) were investigated. A fixed proton dose of 51015 cm2 with 5, 10,
and 15 MeV irradiation energies was used in this study. For the dc characteristics, degradation was
observed for sheet resistance, transfer resistance, contact resistivity, saturation drain current,
maximum transconductance, reverse-bias gate leakage current, and sub-threshold drain leakage
current for all the irradiated HEMTs; however, the degree of the degradation was decreased as the
irradiation energy increased. Similar trends were obtained for the rf performance of the devices,
with 10% degradation of the unity gain cut-off frequency (fT) and maximum oscillation
frequency ( fmax) for the HEMTs irradiated with 15 MeV protons but 30% for 5 MeV proton
irradiation. The carrier removal rate was in the range 0.66–1.24 cm1 over the range of proton
energies investigated
