Growth characteristics of corundum-structured α-(AlxGa1−x)2O3/Ga2O3 heterostructures on sapphire substrates

• Higher temperature growth improved the crystallinity of α-(AlGa)2O3.
• Growth characteristics of α-(AlGa)2O3/Ga2O3 heterostructures was investigated.
• Nearly coherent growth of α-(AlGa)2O3 was evidenced for Al composition of <38%.
• The type-I band lineup was expected for the heterostructure.

We report improved growth conditions for corundum-structured α-(AlxGa1−x)2O3, followed by the growth characteristics of α-(AlxGa1−x)2O3/Ga2O3 heterostructures with the use of mist chemical vapor deposition (CVD) technology. Higher growth temperatures, 700–800 °C, were effective for better crystalline quality especially for higher Al composition x. Coherent growth of α-(AlxGa1−x)2O3 was achieved for x=0.03 and 0.11 with the film thickness of about 100 nm. The type-I band lineup was expected for the heterostructure.