The effects of proton irradiation on the electrical properties of NbAlO/AlGaN/GaN MIS-HEMT

AlGaN/GaN metal-insulator-semiconductor high electron-mobility transistors (MIS-HEMTs) with atomic layer deposited (ALD) NbAlO gate dielectric were investigated using 3 MeV proton irradiation at a fluence of 10 15 p/cm 2 . It was found that the proton irradiation damage caused degradation in DC performance and a flatband voltage shift in the capacitance-voltage curve. Gate-drain conductance measurements indicated that new traps were introduced in GaN from the irradiation, and the trap densities increased from 1.18×10 12 cm −2 ·eV −1 to 1.82×10 12 cm −2 ·eV-1 in MIS-HEMTs after irradiation. However, these increases in trap densities caused by irradiation in MIS-HEMT are less than those in HEMT, which can be attributed to the protection of the AlGaN surface by the NbAlO dielectric layer.