Impact of AlGaN barrier recess on the DC and dynamic characteristics of AlGaN/GaN schottky barrier diodes with gated edge termination

Abstract

The impact of AlGaN barrier recess on the leakage, forward voltage, and dynamic characteristics of Al-GaN/GaN Schottky barrier diodes with gated edge termination (GET-SBDs) has been investigated. With 4-nm remaining AlGaN barrier in the recessed anode region, GET-SBDs show a median leakage current of 1 nA/mm and a forward voltage of 1.26 V. We found out that the leakage current of GET-SBDs gradually reduces with the number of recess cycles. A two-dimensional TCAD simulation also shows a reducing electric field with increasing recess depth, at the corner of the Schottky contact. Furthermore, pulsed I-V measurements were performed, showing that recessed GET-SBDs feature a higher increase of the forward voltage after recess, compared with non-recessed GET-SBDs. This observation has been explained by a trapping mechanism occurring at the corner of the edge termination.