High voltage silicon carbide Junction Barrier Schottky rectifiers

Abstract

The Junction Barrier Schottky (JBS) diode has the advantage of a low forward voltage drop comparable to that of Schottky diodes, as well as a high blocking voltage and low reverse leakage current of a pn diode. This device, originally demonstrated in silicon technology, is especially attractive for wide bandgap materials such as silicon carbide (SiC) in which pn diodes have a large forward voltage drop. Two different JBS designs in 6H SiC have been fabricated, and the electrical characteristics have been compared to Schottky and pn diodes on the same wafer. Although the ion implanted pn diodes had remaining implant damage, the JBS diodes worked well. The JBS diodes were capable of blocking up to 1100 V with a leakage current density of 0.15 A/cm/sup 2/, limited by the leakage when the drift region was fully depleted, or breakdown of the SiC material itself. The forward conduction was limited by an on-resistance of 20 m/spl Omega/ cm/sup 2/.