Effect of high temperature homoepitaxial growth of β-Ga2O3 by hot-wall metalorganic vapor phase epitaxy

•Homoepitaxial growth of (010) β-Ga2O3 layers by hot-wall MOVPE was investigated.•All the layers grown at 800–1000 °C were single-crystalline without twinning.•A homoepitaxial layer with a smooth surface could be grown at 1000 °C.•The concentration of C impurities decreased by high temperature growth.•Nd – Na values approximately equal to Si impurity concentration were obtained. The effect of high temperature homoepitaxial growth of (010) β-Ga2O3 layer by low pressure hot-wall metalorganic vapor phase epitaxy was investigated. In the growth-temperature range 800–1000 °C, the growth rate decreased with increasing growth temperature and the growth mode changed from three-dimensional island growth to two-dimensional step-flow growth. At 1000 °C, a smooth, twin-free single-crystalline homoepitaxial layer with a structural quality equivalent to that of the substrate could be grown. As the growth temperature increased, the concentration of precursor-derived C impurities decreased, while that of unintentionally incorporated Si impurities increased. It was found that the grown layers were all n-type and showed an effective donor concentration approximately equal to the Si impurity concentration regardless of the C impurity concentration.