Unterminated 4H-SiC Schottky barrier diodes with novel HfNxBy electrodes

4H-SiC Schottky barrier diodes (SBDs) were fabricated and characterized from room temperature to 573 K using HfNxBy as Schottky electrodes. The results are compared to SBDs fabricated using other electrodes that include Ni, Pt, Ti and Au. The Schottky barrier height Φb for as-deposited HfNxBy/n−/n+ diodes, determined from room temperature current–voltage characteristics, is 0.887 eV. This is lower than those of SBDs fabricated using other metals such as Au, where Φb is 1.79 eV. The HfNxBy/n−/n+ diodes studied have a much higher on-resistance Ron of around 38.24 mΩ-cm2, which is about four times that of Au/n−/n+ diodes, due to the higher sheet resistance of the sputtered HfNxBy electrode layer. The barrier height Φb and ideality factor η of the HfNxBy/n−/n+ diodes remain almost unchanged after 400 and 750 °C anneal in N2. This suggests excellent thermal and chemical stability of HfNxBy in contact with 4H-SiC.