Comprehensive TCAD Simulation Study of High Voltage (>650V) Common Drain Bidirectional AlGaN/GaN HEMTs

A broad TCAD simulation analysis of a monolithic common drain bidirectional GaN HEMT was performed. We used gate-to-gate distances of 4 microns and 6 microns for the devices optimized with two field plates. The breakdown voltages were 675V and 915V respectively. Inclusion of field plates near both the gates produced electric field peaks at the opposite ends of the transistor simultaneously. This resulted in better electric field management or higher blocking voltage per unit length. Consequently, the 675V monolithic bidirectional HEMT had an impressive 40% improvement in on-resistance than its 650V typical series/parallel counterpart.