Breakdown voltage characteristics of SiC Schottky barrier diode with aluminum deposition edge termination structure

This paper demonstrates the fabrication of and gives a comparison of different metal edge termination structures including aluminum (Al)-deposited guard ring and Al-deposited guard ring-assisted field limiting ring (FLR) for a high-breakdown-voltage silicon carbide (SiC) Schottky-barrier diode (SBD). In order to investigate the application feasibility of the Al-deposition junction termination to a high-breakdown-voltage SiC-SBD, three types of SiG-SBDs are fabricated by using conventional photolithography, electron beam evaporation, and thermal treatment techniques without ion implantation and thermal oxidation procedures. The breakdown-voltage characteristics of the SiG SBD are significantly improved with the Al-deposition edge termination. The SiC-SBD without the edge termination shows less than 250-V breakdown voltage, while the Al-deposited guard ring and Al-deposited guard ring-assisted FLR structures show approximately 700-V and 1200-V breakdown voltages, respectively. The pronounced improvement in the breakdown-voltage characteristics is attributed to the reduction of electric field at the Schottky contact edge well by the Al-deposition edge termination.