Low Power Dissipation SiC Schottky Rectifiers with a Dual-Metal Planar Structure

Dual-metal-planar rectifiers were fabricated on both 6H- and 4H-SiC using Ti and Ni2Si as Schottky metals. The forward I-V characteristics of the dual-metal devices were comparable with those of Ti diodes. On the other hand, under reverse bias, a low leakage current level similar to the Ni 2Si rectifiers was achieved, e.g. on 6H-SiC even a factor 1000 lower than Ti diodes. The fabricated diodes allowed to obtain a power dissipation in the range 0.37-0.53 W/cm2, significantly lowered with respect to the Ti and Ni2Si diodes dissipation. The results were explained with the pinch-off of the low Schottky barrier of Ti by the surrounding high barrier of Ni2Si in reverse bias.