1/ $f$ Noise in As-Processed and Proton-Irradiated AlGaN/GaN HEMTs Due to Carrier Number Fluctuations

We find that the low-frequency 1/f noise of AlGaN/GaN HEMTs before and after 1.8-MeV proton irradiation is more consistent with a carrier-number fluctuation model that includes a non-constant defect-energy distribution Dt(Ef) than with the Hooge mobility fluctuation model. A strongly varying Dt(Ef) in these devices is confirmed by measurements of the voltage and temperature dependence of the noise...