Growth and characterization of α-, β-, and ε-phases of Ga2O3 using MOCVD and HVPE techniques.

Heteroepitaxial films of Ga₂O₃ were grown on c-plane sapphire (0001). The stable phase β-Ga₂O₃ was grown using the metalorganic chemical vapor deposition technique, regardless of precursor flow rates, at temperatures between 500°C and 850°C. Metastable α- and ε-phases were grownwhen using the halide vapor phase epitaxy (HVPE) technique, at growth temperatures between 650°C and 850°C, both separately and in combination. XTEM revealed the better lattice-matched α-phase growing semi-coherently on the substrate, followed by ε-Ga₂O₃. The epitaxial relationship was determined to be [1100] ε-Ga₂O₃ || [1120] α-Ga₂O₃ || [1120] α-Al₂O₃. SIMS revealed that epilayers forming the ε-phase contain higher concentrations of Cl introduced during HVPE growth. [ABSTRACT FROM AUTHOR]