Electric-field-related reliability of AlGaAs/GaAs power HFETs: bias dependence and correlation with breakdown

This work shows experimental and simulated data of hot electron degradation of power AlGaAs/GaAs HFETs with different gate lengths and recess widths, and uses them to infer general indications on the bias and geometry dependence of the device high-field degradation, the meaningfulness of the breakdown voltage figure of merit from a reliability standpoint, and the physical phenomena taking place in the devices during the stress and leading to performance degradation. Possible formulations of a voltage-acceleration law for lifetime extrapolation are also tested.