Recent Advanced Ultra‐Wide Bandgap β‐Ga2O3 Material and Device Technologies

Abstract Gallium oxide (Ga 2 O 3 ) is an emerging ultra‐wide bandgap (UWBG) semiconductor material that has gained significant attention in the field of high voltage and high frequency power electronics. Its noteworthy attributes include a large bandgap (E g ) of 4.8 eV, high theoretical critical breakdown field strength (E C ) of 8 MV cm −1 , and saturation velocity (ν s ) of 2 × 10 7 cm s −1 , as well as high Baliga figures of merit (BFOM) of 3000. In addition, Ga 2 O 3 has the advantages of large‐size substrates that can be achieved by low‐cost melt‐grown techniques. This review provides a partial overview of pivotal milestones and recent advancements in the Ga 2 O 3 material growth and device performance. It begins with a discussion of the fundamental material properties of Ga 2 O 3 , followed by a description of substrate growth and epitaxial techniques for Ga 2 O 3 . Subsequently, the contact technologies between Ga 2 O 3 and other materials are fully elucidated. Moreover, this article also culminates with a detailed analysis of Ga 2 O 3 ‐based high voltage and high frequency power devices. Some challenges and solutions, such as the lack of p‐type doping, low thermal conductivity, and low mobility are also presented and investigated in this review.