A Review of Vertical Ga₂O₃ Diodes: From Fabrication to Performance Optimization and Future Outlooks

The demand for compact, high-power electronic devices, such as power trains, and smartphone chargers, continues to grow, driving advancements in power electronics. Traditional silicon-based semiconductors are increasingly unable to meet the performance requirements of these applications due to their physical limitations. As a result, wide bandgap (WBG) materials like silicon carbide and gallium nitride are now widely used for their superior capabilities, although their fabrication remains costly and complex. Recently, gallium oxide (Ga₂O₃) has emerged as a promising alternative, offering an ultra WBG of 4.8 eV and a breakdown electric field of 8 MV cm⁻¹ while benefiting from relatively simple and cost-effective growth methods. Despite these advantages, Ga₂O₃ has limitations, including low electron mobility and poor thermal management, which restrict its use primarily to high-voltage, low-frequency applications such as diodes. This article analyzes recent developments in Ga₂O₃ diodes, providing an overview of their properties, fabrication techniques, and application-specific performance. The challenges Ga₂O₃ diodes currently face are examined, particularly in thermal management and electron mobility, and ongoing research efforts aimed at overcoming these issues to enable broader use of Ga₂O₃ diodes in power electronics are discussed.