Gated van der Pauw measurements: A powerful tool for probing electron trapping effects in GaN HEMTs

Gated van der Pauw structures can be used to distinguish between different trapping effects in AlGaN/GaN HEMT layers, and evaluate trap density. Activation energies can also be obtained [2]. The absence of transistor access region effects greatly simplifies the interpretation of the data compared to transistor pulsed I-V experiments.