为了寻找可能替代蓝宝石作为氮化镓外延的新型衬底,通过48 h的气相传输平衡,分别在1000℃、1030℃、1050℃、1070℃和1100℃制备了一层单相多晶的γ铝酸锂膜。X射线衍射和扫描电镜分别用于表征膜的物相、取向和表面形貌。结果显示,γ铝酸锂择优取向的好坏取决于气相平衡传输温度,在1050℃制备的γ铝酸锂具有高度的[100]择优取向;在γ铝酸锂(001)面上的双轴拉应力可能有助于[100]择优取向的形成;γ铝酸锂晶粒表面裂纹的方向一致性与其择优取向紧密相关。上述结果表明在合适的工艺条件下,气相传输平衡法制备的γ铝酸锂/蓝宝石可能成为一种很有前景且适合(1-100)面氮化镓生长的复合衬底。 In order to find a new substrate that could replace sapphire as a gallium nitride epitaxial layer, a single-phase polycrystalline γ-alumina was prepared at 1000 ℃, 1030 ℃, 1050 ℃, 1070 ℃ and 1100 ℃, respectively, Lithium oxide film. X-ray diffraction and scanning electron microscopy were used to characterize the phase, orientation and surface morphology of the membrane. The results show that the preferred orientation of γ-lithium aluminate depends on the gas-phase equilibrium transport temperature. The γ-lithium aluminate prepared at 1050 ℃ has a high [100] preferred orientation. The biaxial Tensile stress may contribute to the formation of [100] preferred orientation; the directional uniformity of the surface cracks in γ-lithium aluminate is closely related to its preferred orientation. The above results show that the lithium-γ-lithium aluminate / sapphire prepared by the gas-phase transport equilibrium method may be a promising composite substrate suitable for growth of (1-100) gallium nitride under appropriate process conditions.