Evaluation of GaN HEMT degradation by means of pulsed I-V, leakage and DLTS measurements

The effects of short-term step-stress on the performance of GaN HEMTs have been evaluated for the first time by means of current deep-level-transient-spectroscopy (DLTS) measurements. When subjected to high reverse gate bias the devices experienced an increase in the drain current dispersion as well as in the gate current. Current DLTS measurements carried out during the stress experiment show that the device degradation can be associated to the formation of a defect that is thermally activated with an energy of 0.5 eV.