Metalorganic vapor-phase epitaxy of β-(Al Ga1-)2O3 on (2¯ 0 1) Ga2O3 substrates

Thin β-(AlxGa1-x)2O3 films were grown on (2¯ 0 1) β-Ga2O3 substrates via metal organic chemical vapor deposition (MOCVD). The Al content and band gap energy of β-(AlxGa1-x)2O3 was quantified using high-resolution X-ray photoelectron spectroscopy, through which a band gap energy of 5.26 eV was determined for a 24.1 % Al content. A smooth surface with a bar-like particle morphology was observed via atomic force microscopy and scanning electron microscopy. It was proposed that the film growth exhibited a step bunching model and the roughness of β-(AlxGa1-x)2O3 was decreased at higher Al contents. Finally, β-(AlxGa1-x)2O3/Ga2O3 multi-quantum well structures with a high crystal quality and sharp interface were grown and characterized.