1 Ω On-Resistance Diamond Vertical-Schottky Barrier Diode Operated at 250 °C

Vertical-structured diamond Schottky barrier diodes with a thick field plate have been developed. The diamond VSBD with a 30 µm square (8.8×10-6 cm2) Schottky electrode shows specific on-resistance and blocking voltage, such as 29.3 mΩ cm2 (3.3 kΩ) and 842 V at room temperature, respectively, however, the lower specific on-resistance with a constant blocking voltage such as 9.4 mΩ cm2 (1 kΩ) and 840 V, respectively, have been realized at 250 °C. As a result, Baliga's figure of merit (BVBD2/RonS) is improved from 24.1 to 75.3 MW/cm2. This value is the best in diamond diodes at present. The diamond VSBD with a 1,000 µm square (9.7×10-3 cm2) Schottky electrode shows high forward current and low on-resistance, such as more than 5 A and 10.2 mΩ cm2 (1.04 Ω), respectively, at 250 °C. The estimated parasitic resistance of the SBD is less than 0.04 Ω.