Impact of RIE Etching on the Breakdown Voltage of 4H-SiC Mesa Diodes

This paper presents a comparison of the reverse characteristics of mesa terminated PiN diodes fabricated on n- and p-type 4H-SiC substrates. For n-type the attained breakdown voltages are higher and for p-type lower than expected. This is likely to be explained by the presence of negative charges at the interface between passivation oxide and SiC. Supported by XPS data we come to the conclusion that the RIE process creates surface charges which have an impact on the breakdown voltage of the fabricated diodes.