Degradation of AlGaAs/GaAs Power HFETs Under On-State and Off-State Breakdown Conditions

This work shows a detailed comparison of the degradation caused by off-state and on-state breakdown conditions in power AlGaAs/GaAs HFETʹs. Stress experiments carried out at gate-drain reverse currents up to 3.3 mA/mm (for a total of more than 700 h) show a remarkably larger degradation for the off-state stress, due to more pronounced electron heating at any fixed value of gate reverse current. The degradation modes include VT and RD increase and loss and gm reduction. © 1999 Elsevier Science Ltd. All rights reserved.