2.4 kV Vertical GaN PN Diodes on Free Standing GaN Wafer Using CMOS-Compatible Contact Materials

This paper reports vertical Gallium nitride (GaN) PN diodes on free-standing GaN wafer using a complementary metal-oxide-semiconductor compatible contact materials. Static and switching current-voltage measurements have been carried out to evaluate the fabricated vertical GaN PN diodes. The vertical GaN PN diode in this paper shows turn-on voltage Von of ~3.3-3.4 V, on/off current ratio of ~2.7 × 10⁷, and ideal factor n of ~2.1. The reverse recovery time Trr is 21.2 ns and 23.2 ns, respectively, under a testing temperature of 300 K and 500 K. With an on-state resistance Ron of 3.9 mΩ·cm² and a breakdown voltage V_BR of 2.4 kV, this device achieves a power device figure-of-merit V_BR²/R_on of 1.5×10⁹ V²Ω^-1cm^-2.