Enhancing key performance of vertical GaN schottky barrier diodes through AlO_x insertion and dual ion co-implantation

The main challenges in current vertical GaN diodes involve electric field crowding effects and ohmic contacts on the nitrogen face (N-Face). Extensive prior research has been conducted in these areas. In this study, we introduced a novel dual-ion (carbon and helium) co-implantation edge termination (ET), aiming to enhance the breakdown voltage (VBR) capability of vertical GaN Schottky barrier diodes (SBDs). Furthermore, atomic layer deposition (ALD) was applied on the N-face to deposit a 1.2 nm aluminum oxide (AlOx) layer, effectively reducing the contact resistance of the ohmic contacts (ρ c). The fabricated devices exhibit a low turn-on voltage Vonof 0.56 V and a high Ion/Ioffof ∼ 109. The introduction of AlOx mitigates the Fermi-level pinning effect (FLP), reducing the device resistance Ron,spfrom 3.01 mΩ· cm2 to 1.34 mΩ· cm2. Moreover, the dual-ion co-implantation ET enables the devices to achieve a maximum VBR of 1410 V, resulting in a high figure of merit (FOM) of 1.48 GWcm2.