Design of 1.2 kV SiC MOSFETs by Using Internal SBDs for Enhancing Switching Characteristics

We propose 1.2 kV Silicon Carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs) integrating internal Schottky barrier diodes (SBDs) on the JFET region. The internal SBDs of 1.2 kV SiC MOSFETs have robust switching performance by reducing Miller Pleteau (Qgd) through the wide depletion region formed in the SBD area and by lowering the forward voltage drops (VF) due to the fast operation of integration SBDs. We analyzed the reduced Qgd and forward voltage drop (VF) of the proposed structure compared to the conventional MOSFET and dummy gate MOSFET by optimizing the width of Schottky metal (WSchottky). Additionally, we evaluate the electrical characteristics including on-resistance (Ron), threshold voltage (Vth), breakdown voltage (BV), VF, turn-on loss (Eon) and turn-off (Eoff) for each structures. Our results demonstrate that the switching loss is significantly reduced by the integration of internal SBDs within 1.2 kV SiC MOSFETs.