High-Voltage Regrown Nonpolar m-Plane Vertical p-n Diodes: A Step Toward Future Selective-Area-Doped Power Switches

We report high-voltage regrown nonpolar m-plane p-n diodes on freestandingGaN substrates. A high blocking voltage of 540 V at similar to 1 mA/cm(2) (corresponding to an electric field of E similar to 3.35 MV/cm), turn-ON voltages between 2.9 and 3.1 V, specific on-resistance of 1.7m Omega.cm(2) at 300 A/cm(2), and a minimum ideality factor of 1.7 were obtained for the regrown diodes. Our results suggest that Si, O, and C interfacial impurity levels up to 2 x 10(17) cm(-3), 8 x 10(17) cm(-3), and 1 x 10(19) cm(-3), respectively, at the metallurgical junction of m-plane, p-n diodes do not result in very early breakdown in the reverse bias although the off-state leakage current in the forward bias is affected. The impact of the growth interruption/regrowth on diode performance is also investigated.