The thermal stability of α-(Al _x Ga_1–x )₂O₃ films grown on c-plane sapphire substrates was investigated. The α-(Al _x Ga_1–x )₂O₃ epitaxial films grown by mist chemical vapor deposition were annealed at temperatures in the range of 600 C–1100 C in an atmospheric furnace, and then the crystal structures of the films were characterized using X-ray diffraction and transmission electron microscopy. When the Al composition was less than 0.5, the α-(Al _x Ga_1–x )₂O₃ films converted to the β-phase, which is the thermodynamically most stable phase for Ga₂O₃. The thermal stability was enhanced by increase in the Al composition, and α-(Al _x Ga_1–x )₂O₃ with x=0.45 maintained the corundum structure after annealing at 950 C. On the other hand, the α-(Al _x Ga_1–x )₂O₃ layers with Al contents higher than 0.6 were stable against the thermal treatment and did not show phase transformation to other phases upon high-temperature annealing at 1100 C.

研究了在 c 面蓝宝石衬底上生长的α -(Al _x Ga _{1– x} ) ₂ O ₃薄膜的热稳定性。将雾化化学气相沉积法生长的α -(Al _x Ga _{1– x} ) ₂ O ₃外延薄膜在常压炉中在 600 C–1100 C 的温度范围内退火，然后表征薄膜的晶体结构使用 X 射线衍射和透射电子显微镜。当 Al 成分小于 0.5 时，α -(Al _x Ga _{1– x} ) ₂ O ₃膜转变为β相，这是Ga ₂ O ₃热力学最稳定的相。热稳定性通过增加Al组成，和增强的α - （铝_X镓_{1- X}）₂ ö ₃与X = 0.45保持刚玉结构在950℃退火。另一方面之后，α - （铝_x Ga _{1– x} ) ₂ O ₃ Al 含量高于 0.6 的层对热处理是稳定的，并且在 1100 C 的高温退火后没有显示出向其他相的相变。