Storage and release of buffer charge in GaN-on-Si HEMTs investigated by transient measurements

This paper investigates the kinetics of the non-monotonic trapping mechanisms responsible for dynamic-Ron in GaN-on-Si E-mode transistors. We describe the time-dependences of electron trapping at CN-acceptors and for the first time we investigate the kinetics of the build-up of positive charge at the buffer/strain-relief layer interface. All analysis is carried out on TLMs, by a novel setup capable of measuring current transients (from 10 us to 10 s) after stressing with a negative substrate bias.