High Temperature Operation of Silicon Carbide Schottky Diodes with Recoverable Avalanche Breakdown

Abstract

4H-SiC diodes with nickel silicide (Ni2Si) and molybdenum (Mo) Schottky contacts have been fabricated and characterised at temperature up to 400°C. Room temperature boron implantation has been used to form a single zone junction termination extension. Both Ni2Si and Mo diodes revealed unchanging ideality factors and barrier heights (1.45 and 1.3 eV, respectively) at temperatures up to 400°C. Soft recoverable breakdowns were observed both in Ni2Si and Mo Schottky diodes at voltages above 1450 V and 3400 V depending on the epitaxial structure used. These values are about 76% and 94% of the ideal avalanche breakdown voltages. The Ni2Si diodes revealed positive temperature coefficients of breakdown voltage at temperature up to 240°C.