Comparison of 1200 V silicon carbide Schottky diodes and silicon power diodes

Abstract

This paper describes the design and characterization of 1200 V silicon carbide (SiC) Schottky diodes using a p-n junction barrier to control the leakage current. A low forward voltage drop of 1.9 V at 150 A/cm/sup 2/ and a low leakage current of 300 /spl mu/A/cm/sup 2/ are demonstrated. We compare the performance of SiC Schottky diodes with the 1200 V silicon (Si) PiN diodes fabricated and optimized for military and commercial motor drive applications. The power loss and related voltage and current stress of the SiC Schottky diodes and Si PiN diodes are evaluated using a half-bridge test circuit. The static and dynamic characterization of 1200 V SiC Schottky diodes and Si PiN diodes is performed at 25/spl deg/C and 150/spl deg/C. The SiC Schottky diode exhibits a 30% reduction in the total power loss as compared to the state-of-the-art Si PiN diodes, mainly due to a negligible reverse recovery charge in the SiC Schottky diode, which is 20/spl times/ lower than state-of-the-art Si power diode. Furthermore, the SiC Schottky diode contributes to lowering the overall voltage and current stress by a factor of 6/spl times/ on the switches (in this case IGBTs are used) due to the superior reverse recovery performance of the SiC Schottky diode.