Growth of Ga₂O₃ Thin Films by Dual-Zone LPCVD with Independent Oxygen Supply

β-Ga₂O₃, as an emerging ultra-wide bandgap semiconductor material, holds significant application potential in high-voltage power devices and deep-ultraviolet optoelectronic devices due to its high breakdown electric field, excellent chemical stability, and thermal stability. In this study, high-quality β-Ga₂O₃ thin films with a single (-201) crystallographic orientation were successfully deposited on sapphire substrates using a cost-effective carbothermal reduction low-pressure chemical vapor deposition method. The growth system employed a dual-zone tube furnace, which separates the gallium source zone from the substrate growth zone and supplies oxygen independently to the substrate region. This design enables the independent control of process parameters in different zones, effectively suppresses gas-phase parasitic reactions, enhances the degree of freedom in process regulation, and significantly improves the controllability of film growth. The effects of substrate temperature and chamber pressure on the crystalline quality, surface morphology, and optoelectronic properties of the films were systematically investigated. Based on these investigations, a reproducible growth process for high-quality β-Ga₂O₃ thin films was optimized and established, providing a feasible and low-cost preparation method for high-quality β-Ga2O3 films.