High voltage Ni/4H-SiC Schottky rectifiers

In this paper, we report characteristics of 4H-SiC Ni/Al Schottky rectifiers operating at 1.5 to 2.5 kV and terminated using low energy Ar implants. At room temperature, the nickel Schottky diode exhibited a barrier height of 1.7 eV and an ideality factor of 1.07. After annealing, the Schottky diode fabricated on a 20 μm thick epilayer had a forward voltage drop of 1.16 V at 100 A/cm², the lowest value ever reported for a 1.6 kV rectifier. A breakdown voltage of >2500 V was measured on diodes fabricated using 40 μm epilayers. The measured specific on-resistance of 20 μm and 40 μm epi diodes was within ~1.5× of the calculated drift region resistance over a 0-200°C temperature range