Understanding the degradation sources under ON-state stress in AlGaN/GaN-on-Si SBD: Investigation of the anode-cathode spacing length dependence

In this paper, we report an analysis of the degradation induced by ON-state stress in Au-free AlGaN/GaN-on-Si Schottky barrier diodes (SBDs). When the device operates in ON-state mode, the combined effect of large currents and moderate electric fields may cause a shift of the turn-on voltage (VTON) and ON-resistance (RON) because of the charge carrier trapping/de-trapping, occurring in different regions and related to different types of defects. In particular, the influence of the anode-cathode spacing length on the ON-state degradation has been investigated and the degradation sources, attributable to ΔVTON and ΔRON, have been understood. Moreover, thanks to this approach, a critical electric field for the RON degradation has been reported