Improved 4H-silicon carbide Schottky diodes using multiple metal alloy contacts

Abstract

In this paper we report on Schottky diodes fabricated in 4H-SiC. The diodes fabricated utilized a three metal layer at the Schottky interface and a two metal layer at the back ohmic contact. Results are compared to diodes fabricated previously using a single metal layer at both Schottky and ohmic interfaces. Comparison shows an improvement in barrier height consistency, breakdown voltage and reverse leakage current. Boron implantation was used to increase reverse breakdown via an edge termination. Breakdown voltages in excess of the measurement equipment maximum of 1000 V were achieved by 40% of the fabricated diodes post implantation.