Characterization of Electrical Switching Safe Operation Area on Schottky-Type P-GaN Gate HEMTs

Gallium nitride (GaN) high electron mobility transistors (HEMTs) have demonstrated their superior performance in consumer electronics. However, their longer-lifetime-demanding application has not been well-explored yet, due to the limited electrical reliability, especially the existence of ON-resistance degradation in hard-switching conditions. In this article, four testing modes, including double-pulse testing (DP), continuous hard switching testing (HSW), high-voltage dc stress testing (DC) and recovery testing (RE), are adopted to characterize time-resolved dynamic R-ON of GaN HEMT devices, based on the multimode evaluation platform. Much higher dynamic R-ON is obtained by time-resolved characterization, compared with traditional double-pulse testing. The contribution of the dc-stress- or transient-stress-induced dynamic R-ON is distinguished by our proposed stressing sequence (DC-HSW-DC-RE). Based on the stressing pattern, a novel physical-based characterization method is delivered to identify the irreversible degradation of dynamic R-ON on GaN power devices, featuring excellent sensitivity for irreversible degradation detection. In addition, lifetime acceleration experiments are conducted, and the R-ON degradation shows strong dependence on voltage and current, and weak dependence on temperature. Finally, switching safe operation area and switching lifetime are plotted.