The Impact of Anode p⁺ Islands Layout on the Performance of NiO_x/P-Ga²O³ Hetero-Junction Barrier Schottky Diodes

In this work, 1-mm(2) NiOx/P-Ga2O3 heterojunction barrier Schottky (HJBS) diodes with Stripe and honeycomb anode p(+) islands layout are compared in static characteristics, reverse recovery characteristics, and surge current robustness for the first time. In comparison with Stripe HJBS diodes, although Honeycomb HJBS diodes have a slightly higher turn-on voltage and resistance, the breakdown voltage (BV) is increased by 38% and the B-FOM is increased by 59%. A 3-D TCAD simulation also proves that the peak electric field of the honeycomb layout is lower than that of the stripe layout under the same bias. The reverse recovery test shows that both devices have nanosecond reverse recovery time. In addition, Honeycomb HJBS diodes have a better surge current robustness than Stripe HJBS diodes, which is attributed to the better heat dissipation capability of the honeycomb layout proved by a 3-D TCAD thermal simulation. The structural parameters of the honeycomb layout are optimized using 3-D TCAD simulation, and the results show that reducing the cell size can further improve its forward conduction ability. These results manifest that the honeycomb layout can further enhance the power performance of NiOx/P-Ga2O3 HJBS diodes, and has immense potential in power applications.