Off-state breakdown effects on gate leakage current in power pseudomorphic AlGaAs/InGaAs HEMTs

The effects of off-state breakdown on characteristics of power AlGaAs/InGaAs pseudomorphic HEMTs (PHEMTs) are investigated in detail. While the gate leakage current is substantially decreased after breakdown stress, no obvious changes in drain-to-source current and transconductance are observed. Prior to breakdown stress, gate leakage current shows a nearly ideal 1/f noise characteristic with an Ig/sup 2/ dependence, suggesting a surface generation-recombination current from the interface of the passivation layer. After stress, the gate current noise can be drastically reduced. The results suggest an alternative for alleviating the gate leakage current in PHEMTs.