Vertical GaN Power Transistor with Embedded Fin-shaped Diode for High Performance Power Conversion

A vertical GaN power transistor featuring embedded Fin-shaped diode (FDMOS) with intrinsic reverse conduction is proposed. Its static and dynamic performance is investigated by Sentaurus TCAD. Owing to the embedded Fin-shaped diode, the reverse characteristics of the device are independent of the turn-on voltage of the body diode, and thus a low reverse turn-on voltage
$(V_{\mathrm{R},\mathrm{ON}})$
of 0.9 V and a low reverse recovery charge
$(Q_{\mathrm{rr}})$
of 1.36 f.lC is obtained. Benefiting from the removal of MOS structure above the JFET region, the gate charge (Q
GD
) of the FDMOS is also significantly reduced, and thus the lower switching loss is achieved.
$Q_{\mathrm{GD}}$
is as low as 114 nC/cm
²
, which is only 43% of that in the Con. MOS. The turn-on loss (
$E_{ON}$
) of the FDMOS reduces by 33.8% in comparison with that of the Con. MOS. In addition, the integration of the Fin-shaped diode reduces the parasitic inductance and the total chip area compared with the conventional method of using an external Schottky diode.