LiTaO₃基板上へのα-Ga₂O₃の成長にα-Fe₂O₃バッファ層の成長時間が与える影響

抄録

Corundum structured α-Ga₂O₃ is a promising semiconductor material for power switching devices due to its large bandgap (5.3 eV). The high dislocation density of α-Ga₂O₃ caused by a large lattice mismatch between the α-Ga₂O₃ and a sapphire substrate is a significant issue to a high-reliability operation. We featured LiTaO₃ substrates exhibiting a near corundum structure as growth substrates to decrease the lattice mismatch. Our previous study revealed that the growth of α-Ga₂O₃ on LiTaO₃ substrates required α-Fe₂O₃ buffer layers. In this study, the impact of α-Fe₂O₃ buffer layer growth time on the growth of α-Ga₂O₃ was investigated. X-ray diffraction 2θ-ω analysis revealed that α-Ga₂O₃ was successfully grown by inserting α-Fe₂O₃ buffer layer regardless of the buffer layer growth time. The growth time of the α-Fe₂O₃ buffer layer affected the number of edge dislocations examined by XRD rocking curve (XRC) measurements. The smallest full width at half maximum of XRC measurements at (0006) plane of the α-Ga₂O₃ with the buffer layer growth time of 1min was 60 arcsec. The α-Ga₂O₃ with the buffer layer growth time of 1 min had a smooth surface. This study contributes power switching device application of α-Ga₂O₃ grown on LiTaO₃ substrates.