Layer-by-layer growth of ε-Ga2O3 thin film by metal-organic chemical vapor deposition

Layer-by-layer morphology is a crucial signature of the quality of epitaxial thin films. In this study, layer-by-layer growth of an epsilon-phase gallium oxide (epsilon-Ga2O3) thin film is demonstrated using metal-organic chemical vapor deposition. A two-step growth method, in which a nucleation layer is grown at 600 degrees C and an epilayer is grown at 640 degrees C, is employed to fabricate a high-quality epsilon-Ga2O3 thin film on a c-plane sapphire substrate. The morphology of the epsilon-Ga2O3 film is evaluated by atomic force microscope. The density of screw-type threading dislocations determined by an X-ray diffraction rocking curve is as low as 1.8 x 10(8)cm(-2). (C) 2018 The Japan Society of Applied Physics