High-voltage Ni- and Pt-SiC schottky diodes utilizing metal field plate termination

Abstract

diodes utilizing a metal-oxide overlap structure for electric field termination. This simple structure when used with a high barrier height metal such as Ni has consistently given us good yield of Schottky diodes with breakdown voltages in excess of 60 % of the theoretically calculated value. This paper presents the design considerations, the fabrication procedure, and characterization results for these 1 kV Ni–SiC Schottky diodes. Comparison to similarly fabricated Pt–SiC Schottky diodes is reported. The Ni–SiC ohmic contact formation has been studied using Auger electron spectroscopy and X-ray diffraction. The characterization study includes measurements of current–voltage (IV) tempera-ture and capacitance–voltage (CV) temperature characteristics. The high-temperature performance of these diodes has also been investigated. The diodes show good rectifying behavior with ON/OFF current ratios, ranging from 106 to 107 at 27 C and in excess of 106 up to 300 C. Index Terms—Power devices, Schottky diodes, silicon carbide. I