Mist CVD Technology for Gallium Oxide Deposition: A Review

Abstract

Mist chemical vapor deposition (mist CVD) technology originated from early metal organic chemical vapor deposition (MOCVD) techniques. By mist CVD, High-quality oxide films are deposited by ultrasonic atomization of low-concentration precursor solutions under atmospheric pressure and relatively low temperature conditions. Mist CVD was first reported in 1990, and in 2008, Shinohara et al. applied mist CVD to the growth of gallium oxide (Ga₂O₃) epitaxial films. As an ultrawide bandgap (UWBG) semiconductor, Ga₂O₃ has tremendous potential in power systems and optoelectronic devices, attracting significant attention and becoming a research hotspot in recent years. Various techniques have been explored for growing Ga₂O₃ films. Among them, mist CVD is noted for its relatively cheap equipment, simpler operation, and competitive cost advantages, making it a promising method for Ga₂O₃ film growth. Using mist CVD, five crystal phases (α, β, γ, ε, and δ) of Ga₂O₃ films have been successfully produced, and the properties of Ga₂O₃ films can be easily tuned through doping and alloy engineering. Additionally, semiconductor devices have been fabricated using Ga₂O₃ films grown by mist CVD. However, challenges remain in terms of doping uniformity, crystal phase purity, and stability. This paper reviews the advancements in mist CVD for the deposition of Ga₂O₃, covering mist CVD equipment design, Ga₂O₃ crystal phase control, doping and alloy modulation, and device fabrication.