Fabrication of a monolithic 4H-SiC junction barrier schottky diode with the capability of high current

Abstract

There is a great interest in monolithic 4H-SiC Junction Barrier Schottky (JBS) diodes with the capability of a high forward current for industrial power applications. In this paper, we report large-area monolithic 4H-SiC JBS diodes fabricated on a 10 µm 4H-SiC epitaxial layer doped to 6×1015 cm−3. JBS diodes with an active area of 30 mm2 had a forward current of up to 330 A at a forward voltage of 5 V, which corresponds to a current density of 1100 A/cm2. A near ideal breakdown voltage of 1.6 kV was also achieved for a reverse current of up to 100 μA through the use of an optimum multiple floating guard rings (MFGR) termination, which is about 87.2% of the theoretical value. The differential specific-on resistance (R SP-ON) was measured to be 3.3 mΩ cm2, leading to a FOM (VB2/R SP-ON) value of 0.78 GW/cm2, which is very close to the theoretical limit of the tradeoff between the specific-on resistance and breakdown voltage for 4H-SiC unipolar devices.