Lateral β-Ga 2 O 3 Schottky barrier diodes (SBDs) are demonstrated through heterostructure and dielectric engineering aimed at addressing the intrinsic trade-off between on-resistance and breakdown voltage. An optimized device architecture incorporating an (Al 0.21 Ga 0.79 ) 2 O 3 /Ga 2 O 3 barrier layer and a field-plate structure is proposed to mitigate electric-field crowding at the Schottky contact edges, which is a primary cause of excessive leakage current and premature breakdown in conventional lateral Ga 2 O 3 SBDs. The (Al 0.21 Ga 0.79 ) 2 O 3 /Ga 2 O 3 heterointerface induces a potential well that gives rise to a high-density electron channel confined at the heterointerface, enabling efficient carrier transport under forward bias while remaining readily depleted under reverse bias. This behavior is consistent with reduced scattering and interface-dominated transport, rather than bulk conduction. In addition, dielectric passivation engineering is employed to suppress surface-related leakage and improve electric-field redistribution. As a result, the optimized device achieves a breakdown voltage of 1619 V, an on/off current ratio of 2.56 × 10 8 , and a specific on-resistance of 712.5 mΩ·cm 2 , demonstrating balanced performance among lateral β-Ga 2 O 3 SBDs on sapphire substrates. More importantly, the proposed device architecture enables operation governed by heterointerface and lateral geometry, rather than bulk drift-layer properties. These results demonstrate a distinct device concept based on a high-density electron channel confined at the heterointerface combined with sidewall electrode configuration and field-plate engineering, providing a viable pathway toward high-voltage, high-efficiency β-Ga 2 O 3 power diodes on sapphire substrates.
Ye et al. (Mon,) studied this question.