Preliminary Evaluation of PBTI and Back-Effect interplay in 100 V p-GaN gate AlGaN/GaN HEMTs

In this paper, we aim to analyse the behaviour of 100 V p-GaN gate AlGaN/GaN HEMTs under varying measurement conditions, focusing on the interplay between Positive Bias Temperature Instability (PBTI) and the Back-Effect (BE). Two stress sequences have been performed to underline the impact of the hole injection due to the gate voltage, the electrostatic coupling and the negatively ionized buffer traps caused by the substrate voltage, which emulates the application conditions of the high-side device in half-bridge topology. Different behaviours have been observed among the two tests, highlighting in both cases the recovery of the drain current during the stress thanks to relatively high gate potential. This approach allows us to clearly discern the PBTI and BE contributions to the dynamic behaviour of the device under test.