Optimization of the growth temperature of α-Ga2O3 epilayers grown by halide vapor phase epitaxy

We report the optimized temperature for the growth of α-Ga2O3 on α-Al2O3 substrate using halide vapor phase epitaxy. The α-Ga2O3 epilayer grown at 470 °C exhibited the lowest full-width-at-half-maximum values for the (0006) and (10-14) peaks in the X-ray omega-scan rocking curve, which confirmed that the growth temperature strongly influenced the phase transition of Ga2O3 and affected the crystal quality of the α-Ga2O3 epitaxial layers. In addition, the impurity concentration in this α-Ga2O3 epilayer as determined by secondary ion mass spectroscopy was found to be in the range of 1016-1018 cm−3.