Demonstration of β-(Al _x Ga_1−x )₂O₃/β-Ga₂O₃ superlattice growth by mist chemical vapor deposition

Abstract

This study demonstrates the successful growth of a β-(AlxGa1-x)2O3/β-Ga2O3 superlattice structure with six periods using mist chemical vapor deposition (CVD). High-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) analysis revealed that the superlattice consisted of six periods of β-(AlxGa1-x)2O3/β-Ga2O3 with individual layer thickness of 12.9 nm and 9.1 nm, respectively. XRD analysis further confirmed the periodicity of the structure, yielding a period of 22.7 nm, which is in good agreement with the STEM result. Additionally, the Al composition was determined to be x = 0.085 based on XRD peak positions. Both atomic force microscopy and HAADF-STEM observations revealed atomically flat surfaces and sharp interfaces. This achievement highlights the potential of mist CVD for fabricating complex oxide heterostructures, offering a cost-effective and scalable alternative to conventional methods. The findings open new avenues for developing advanced electronic and optoelectronic devices based on wide-bandgap oxides.