Dynamic Switching of 1.9 A/1.76 kV Forward Current NiO/β-Ga₂O₃ Rectifiers

Abstract

The switching performance of vertical geometry NiO/β-Ga2O3 rectifiers with a reverse breakdown voltage of 1.76 kV (0.1 cm diameter, 7.85 x10-3 cm2 area) and an absolute forward current of 1.9 A fabricated on 20 µm thick epitaxial β-Ga2O3 drift layers and a double layer of NiO to optimize breakdown and contact resistance was measured with an inductive load test circuit. The Baliga figure-of-merit of the devices was 175 MW.cm-2, with on-state resistance of 17.8 mΩ.cm2. The recovery characteristics for these rectifiers switching from forward current of 1 A to reverse off-state voltage of -550 V showed a recovery time (trr) of 101 ns, with a peak current value of 1.4A for switching from 640V. There was no significant dependence of trr on switching voltage or forward current.

(Invited) Fabrication and Device Performance of 2.7 Kv/2.5A NiO/Ga2O3 Heterojunction Power Rectifiers

“…The maximum forward current was 2.5 A at 7.8V and was slightly better for the 12.5 nm NiO thickness structure. Both results are a significant improvement over our previous reports (78)(79)(80) .…”

“…The most common of these has been NiO, whose carrier concentration can be controlled by the O2 partial pressure during deposition, and it can also be used as a field plate or edge termination material. We have previously reported breakdown voltages of 4.7 kV in such structures (78)(79)(80) and a forward switching current of 1.59A for 1.76kV breakdown voltage, larger area rectifiers (79) .…”

Superior high temperature performance of 8 kV NiO/Ga2O3vertical heterojunction rectifiers

“…The switching characteristics of the rectifiers are also of paramount interest, since they need fast recovery times and the ability to switch large currents. [45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63] Fig. 9 shows the temperature dependence of (top) Schottky rectifiers and (bottom) NiO/ Ga 2 O 3 heterojunction rectifiers of reverse recovery characteristics in which the devices were switched from 60 mA forward current to 0 V. The reverse recovery times are B 26 AE 2 ns and are tabulated in Table 1.…”

1 mm2, 3.6 kV, 4.8 A NiO/Ga2O3 Heterojunction Rectifiers

“…100-200 x smaller than the 1 mm 2 devices. 10,45,46 To place the work in context, Fig. 6 shows a compilation of reported Ron vs V B results reported in the literature for Ampereclass rectifiers and includes conventional Schottky barrier or JBS rectifiers and NiO/Ga 2 O 3 heterojunction rectifiers.…”