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.