Investigation of the surface optimization of β-Ga2O3 films assisted deposition by pulsed MOCVD

β-Ga2O3 films were deposited on (-201) homo-substrates by MOCVD. All films were deposited at 800 °C, and TEGa and high-purity O2 were used as Ga and O sources, respectively. The Ga source flow rate significantly influenced the surface morphology. A relatively flat surface was obtained under the flow rates of TEGa and O2 were 40 and 2100 sccm, respectively, with a fine step structure covering the entire surface. The substrate morphology can be greatly improved after cleaning with HF/H2O2 and thermally annealing, promoting the surface flatness of the epilayer. On this basis, a buffer layer assisted by pulsed MOCVD was inserted between the substrate and the epilayer, and the RMS roughness of the epilayer was further reduced to below 1 nm. Continue to deposited the substrate-buffer layer-epilayer structure, reasonably optimized the growth pressure, O2 and TEGa flow rates, successfully realized a higher flatness surface.