Study of 4H-SiC JBS Diodes Fabricated with Tungsten Schottky Barrier

Tungsten is a suitable metal contact for high-temperature applications. We fabricated 1.7-kV and 6-kV 4H-SiC junction barrier Schottky (JBS) diodes with a tungsten Schottky contact with different geometries, and their forward characteristics were measured up to 300°C. The 1.7-kV diodes exhibited unipolar conduction up to 6 V at 275°C, whereas 6-kV diodes showed ideal on-resistance, Ron. An optimized JBS design permits a higher breakdown voltage to be obtained than for the pure Schottky diode, with a reasonable increase (10%) of the on-resistance. Results demonstrate the feasibility of tungsten JBS diodes for fast-switching, high-voltage, and high-temperature applications.