Effect of proton irradiation energy on AlGaN/GaN metal-oxide semiconductor high electron mobility transistors

The effects of proton irradiation energy on dc characteristics of AlGaN/GaN metal-oxide semiconductor high electron mobility transistors (MOSHEMTs) using Al₂O₃ as the gate dielectric were studied. Al₂O₃/AlGaN/GaN MOSHEMTs were irradiated with a fixed proton dose of 5 × 10¹⁵ cm^-2 at different energies of 5, 10, or 15 MeV. More degradation of the device dc characteristics was observed for lower irradiation energy due to the larger amount of nonionizing energy loss in the active region of the MOSHEMTs under these conditions. The reductions in saturation current were 95.3%, 68.3%, and 59.8% and reductions in maximum transconductance were 88%, 54.4%, and 40.7% after 5, 10, and 15 MeV proton irradiation, respectively. Both forward and reverse gate leakage current were reduced more than one order of magnitude after irradiation. The carrier removal rates for the irradiation energies employed in this study were in the range of 127-289 cm^-1. These are similar to the values reported for conventional metal-gate high-electron mobility transistors under the same conditions and show that the gate dielectric does not affect the response to proton irradiation for these energies.