Characterization of trap evolution in GaN-based HEMTs under pulsed stress

Abstract

In this paper, the evolution of traps in GaN-based high-electron-mobility transistors under pulsed thermal stress and the combined effect of thermal stress and electrical stress are studied. By applying impulse stresses of different powers to the device, collecting transient current response curves, and accurately extracting the time constant and absolute peak changes of the traps by employing the Bayesian inverse convolution theory time constant spectral technique, we analyzed the evolution of the traps under the action of impulse stress and clarified the influence and degradation mechanism of the thermal stress, as well as the combined action of thermal stress and electrical stress, on the evolution of traps. The results show that under pulsed stress, the decrease in electron mobility with increasing temperature leads to a decrease in device drain current, and the degradation of the device is exacerbated owing to channel hot-electron injection.