Edge termination study and fabrication of a 4H–SiC junction barrier Schottky diode

The 4H-SiC junction barrier Schottky (JBS) diodes terminated by field guard rings and offset field plate are designed, fabricated and characterized. It is shown experimentally that a 3-μm P-type implantation window spacing gives an optimum trade-off between forward drop voltage and leakage current density for these diodes, yielding a specific on-resistance of 8.3 mΩ·cm². A JBS diode with a turn-on voltage of 0.65 V and a reverse current density less than 1 A/cm² under 500 V is fabricated, and the reverse recovery time is tested to be 80 ns, and the peak reverse current is 28.1 mA. Temperature-dependent characteristics are also studied in a temperature range of 75 ℃-200 ℃. The diode shows a stable Schottky barrier height of up to 200 ℃ and a stable operation under a continuous forward current of 100 A/cm².