Development of Vertical GaN FETs for Bi-directional Battery Charging

In this paper, a vertical device structure and its process flow are proposed for fabrication of Gallium Nitride Trench Field Effect Transistors (GaNTT). A TCAD model is developed to capture effect of bulk and interface traps on the electrical performance of fully vertical Gallium Nitride devices on a Silicon Carbide substrate (GaN-on-SiC). The simulation results show a promising specific on-resistance of R
sp,on
= 1.4 mΩ . cm
²
and a blocking voltage of BV = 540V at V
GS
=0V for a GaN drift thickness of 4 μm.