SiC symmetric blocking terminations using orthogonal positive bevel termination and Junction Termination Extension

Abstract

Symmetric blocking power semiconductor switches require two edge terminations, one for the reverse blocking junction and the other one for the forward blocking junction. In this work, we demonstrated 1100V SiC symmetric blocking edge terminations using orthogonal positive bevel (OPB) termination and a one-zone Junction Termination Extension (JTE). The OPB was formed by orthogonally sawing 45° V-shape trenches into the SiC wafer with a diamond-coated dicing blade. The surface damage was then repaired with dry-etch in SF6/O2 plasma, which reduced the leakage current by around two orders of magnitude. As limited by field reach-through, both the OPB and the JTE terminations show breakdown voltage of 1100V. The P+P-N+ diodes fabricated on the same wafer with the OPB termination showed 1610V avalanche breakdown which was around 83% of ideal value.