Investigation of Fast and Slow Charge Trapping Mechanisms of GaN/AlGaN HEMTs Through Pulsed I-V Measurements and the Associated New Trap Model

This paper presents a new approach to characterize and model charge trapping effects of GaN-based high electron mobility transistors (HEMTs). Two types of deep-level traps (slow-emitting and fast-emitting traps) have been characterized apart by performing dedicated pulsed I-V measurements. Slow-emitting traps have been found triggered by threshold voltages (gate-source and gate-drain) and filled through reverse gate current. The slow-traps filling mechanism is modeled based upon a metal to channel trap assisted tunneling (TAT) physical process. Moreover, the TAT model parameters are extracted from gate-source and gate-drain leakage current measurements. However, the well known fast-emitting traps are classically RC-like modeled. Furthermore, this new full CAD compatible model is validated on a 4 GHz load-pull measurement.