Off-state stress investigation of InAlN/GaN HFETs with different AlN buffer layer

This study is focused on static electrical properties of the InAlN/GaN HFETs with the AlN buffer layer, which have different mechanical strain due to different growth conditions. Investigated devices were tested under off-state high drain bias of 55 V and their performance before and after the stress is analysed. Significant influence of the AlN buffer on the properties of virgin as well as stressed devices, particularly the gate current, is observed.