He-induced semi-insulating microcolumns for high-voltage leakage current suppression in β -Ga2O3 Schottky barrier diodes

Localized semi-insulating regions in β-Ga2O3 are important for modulating the interfacial electric field and leakage characteristics of high-voltage devices. In this work, a high density of acceptor defects, including VGa and Hei, was introduced into the n-type Ga2O3 matrix by He-ion implantation, enabling the in situ formation of semi-insulating microcolumns in Ga2O3. These semi-insulating microcolumns effectively reduce the interfacial electric field near the Schottky junction and decrease the effective anode area of the direct metal/semiconductor contact, thereby significantly suppressing the reverse leakage current. The fabricated Ga2O3 SIMC-SBDs exhibit a leakage current nearly two orders of magnitude lower than that of conventional SBDs at a reverse voltage of 1000 V, while maintaining a breakdown voltage of 1807 V and a specific on-resistance of 4.1 mΩ cm2. This structure provides a viable approach to the design of β-Ga2O3 SBDs with high blocking capability and low leakage current while simplifying the fabrication process.