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

摘要

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·cm^2.A JBS diode with a turn-on voltage of 0.65 V and a reverse current density less than 1 A/cm^2 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°C-200°C.The diode shows a stable Schottky barrier height of up to 200°C and a stable operation under a continuous forward current of 100 A/cm^2.