V<sub>F</sub> Degradation of 4H-SiC PiN Diodes Using Low-BPD Wafers

Abstract

In this paper, we found origin of V F degradation of SiC bipolar devices other than a basal plane dislocation (BPD) in the SiC substrate. A V F degradation of the 4H-SiC PiN diodes with low-BPD wafers was evaluated and its origins were discussed. Some diodes suffered V F degradation, even though they were fabricated on BPD-free area. PL mapping, TEM image, and optical observation after KOH etching showed that there were Shockley stacking faults and combined etch-pits arrays, which were presumed to be caused by the device process.