Threshold voltage drift (PBTI) in GaN D-MODE MISHEMTs: Characterization of fast trapping components

Abstract

V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TH</inf> 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 <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TH</inf> 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.