Recent Advances in the Mist Chemical Vapor Deposition of Ga2O3 Thin Films

Gallium oxide (Ga2O3), as an emerging ultrawide bandgap semiconductor with high breakdown voltage, excellent thermal and chemical stability, has shown great potential for applications in high-voltage power devices and deep ultraviolet optoelectronic detection. To realize its practical applications, low-cost and large-scale manufacturing techniques are urgently needed. In this context, mist chemical vapor deposition (mist CVD) has emerged as an important candidate for Ga2O3 epitaxy, benefiting from its atmospheric-pressure, nonvacuum operation, low equipment and precursor costs, wide process window, and tunable solution chemistry. Hence, this review summarizes the configuration and deposition mechanism of mist CVD. It then systematically reviews recent research progress on the controlled epitaxy of multiple Ga2O3 polymorphs via mist CVD. Particular attention is given to the effects of growth temperature, substrate choice, and other related factors on phase selection. Strategies for improving film crystallinity and surface morphology are discussed, along with the regulation of impurities and defects, such as carbon residues and oxygen vacancies. Furthermore, this review discusses the formation mechanisms of interfacial transition layers and in-plane rotational domain structures in heteroepitaxy, along with the corresponding suppression strategies. Following, the challenges and prospects associated with wafer-scale uniform epitaxy and industrial integration are discussed. This review offers transformative insights into the controllable synthesis of high-quality Ga2O3 epitaxial films by systematically deconstructing prevailing technical bottlenecks. It is envisioned that these discussions will serve as a cornerstone reference, bridging the gap between fundamental material growth and the deployment of next-generation ultrawide bandgap semiconductors in high-power electronics and advanced optoelectronic architectures.