Investigation of electrical transport mechanisms in p-NiO/n-Ga₂O₃ junction barrier Schottky diodes with low leakage and high breakdown voltage

High-performance gallium oxide (Ga2O3) junction barrier Schottky (JBS) diodes were fabricated using planar and trench junction barrier designs. Their electrical transport mechanisms were systematically studied. The JBS integration strengthens interfacial depletion via p-n junction-induced Ga2O3 conduction band elevation, whereas the trench design lowers the conduction band to form a higher interfacial barrier and expands lateral depletion, effectively modulating carrier transport. Additionally, the JBS structure reduces the electric field at the Schottky interface which not only suppresses Schottky barrier lowering to reduce reverse leakage current but also mitigates surface field crowding to prevent premature device breakdown. The forward current density ratios of Schottky barrier diodes (SBDs) with a JBS reached an impressive 8.0 × 1010, demonstrating exceptional switching characteristics. The reverse breakdown voltage of the SBDs with trench JBS increases from 310 V in the SBDs to a remarkable 1150 V, representing roughly a 3.7-time. The leakage current is simultaneously reduced by two orders of magnitude to an ultra-low value of 1.1 × 10-9 A/cm2. A comparative analysis of device performance between planar and trench JBS structures is presented, offering a theoretical foundation and reference for future innovations in Ga2O3-based SBDs.