UV-Assisted Probing of Deep-Level Interface Traps in GaN MISHEMTs and Their Role in Threshold Voltage & Gate Leakage Instabilities

This work demonstrates UV assisted probing of deep level traps in dielectric/GaN interface. The deep level donor traps lead to threshold voltage and gate leakage instabilities in GaN MISHEMTs. While UV exposure excites the deep traps, gate bias can sweep the trap energy state and trigger de-trapping. The recovery transient is evaluated to study the trap time constant. Besides, this work reveals a non-destructive technique to probe intrinsic traps as the UV exposure does not change the trap density across the device.