Hot electron effects on undoped AlGaN/GaN high electron mobility transistors

Summary form only given. In this work, we report on the effects of hot electron stress on the degradation of undoped Al_0.3GaN_0.7/GaN power HEMT´s with SiN passivation, consisting of a decrease in the drain current, an increase in the parasitic drain and source resistance, and a shift in threshold voltage. The stressed devices suffered from aggravated drain current slump (DC to RF dispersion). Pulsed I-V measurements and current-mode deep level transient spectroscopy (DLTS) suggested possible changes in surface charge profiles occurred during hot electron stress test. The nature of degradation under hot electron stress was irreversible.