High-field-induced electron detrapping in an AlGaN/GaN high electron mobility transistor

A step stress test is carried out to study the reliability characteristics of an AlGaN/GaN high electron mobility transistor (HEMT). An anomalous critical drain-to-gate voltage with a negative temperature coefficient is observed in the stress sequence, beyond which the HEMT device starts to recover from degradation induced by early lower voltage stress. While the performance degradation featuring the drain current slump stems from electron trapping in the surface or bulk states during low-to-medium bias stress, the recovery is attributed to high field induced electron detrapping. The carrier detrapping mechanism could be helpful for lessening the trapping-related performance degradation of a GaN-based HEMT.