Identification of electronic traps in AlGaN/GaN HEMTs using UV light-assisted trapping analysis

UV light-assisted trapping analysis in conjunction with electroluminescence studies was employed to identify the location of traps generated in AlGaN/GaN HEMTs submitted to on-state stress. Our results indicate that UV light-assisted trapping is closely related to traps in the access region close to the gate edges. An increase in the dominant electronic trap density spatially located within the AlGaN layer underneath the gate and in the access region close to the drain side of the gate edge was found to be the most pronounced degradation mechanism for the stress conditions investigated. This trap level was found to be located 0.5 eV below the AlGaN conduction band.