Abstract
V TH drift of GaN MISHEMTs under positive gate stress (PBTI) is shown to have a distinct fast component, independent of the gate dielectric material or details of the device architecture. The trap(s) responsible for this V TH degradation component are located at the GaN side of the GaN/dielectric interface. Since these fast traps have capture-and emission-times of the order of 10μs and 1ms respectively, its impact is not evident in the traditional DC characterization, yet it severely impacts device lifetime projections. © 2014 IEEE.