On temperature and hot electron induced degradation in AlGaAs/InGaAs PM-HEMT's

AlGaAs/InGaAs pseudomorphic HEMTs (PM-HEMTs) have been submitted to either hot electron or high temperature storage stress tests, A non-permanent increase of the drain current is observed after the tests and is correlated with the presence of deep levels in the devices, Trapping of holes generated by impact ionization (during the hot electron stress) or thermally activated electron detrapping (during the high temperature storage) are responsible for the observed shifts of the PM-HEMT's characteristics. We also present a new DC based investigation technique that gives information about the localization of the trapped/detrapped charge.