Degradation physics of GaN-based lateral and vertical devices

This paper reviews the most relevant mechanisms responsible for the degradation of GaN-based lateral and vertical electron devices. These components are almost ideal for application in power electronics, but the presence of semiconductor defects and the existence of degradation processes may limit their stability and lifetime. In this paper we focus on the following aspects: (i) the degradation processes induced by off-state conditions and leading to a time-dependent and/or catastrophic breakdown of the devices; (ii) the stability of the gate stack; (iii) the degradation of the electrical performance of vertical GaN transistors and diodes. To discuss these topics, we refer to case studies carried out in our laboratories.