Techniques to fabricate patterned sapphire substrates (PSSs) have attracted much attention in recent decades. Wet etching behaviors and crystalline sapphire processes are critical for PSSs applications to improve the performance of light-emitting diodes. This study investigated the shape evolution behaviors and associated kinetics of cavities on the c-{0001} plane in crystalline sapphire during wet etching. It was revealed that wet etching reduces the cavity aspect ratio, and the cavity shape is a complicated structure constructed by 15 faceted planes of c-{0001}, r-{1$\overline{1}$02}, p-{11$\overline{2}$3}, m-{10$\overline{1}$0}, and s-{1$\overline{1}$01} families. A constant etching rate was demonstrated, suggesting the step flow mechanism of etching. The etching activation energy of crystalline sapphire is reduced by preformation of cavities as elucidated by the Arrhenius kinetic model followed during the etching process. This study provides new insight into wet etching behaviors of crystalline sapphire and might open up a way for fabricating sapphire substrate with large aspect ratio patterns.

近几十年来，制造图案化的蓝宝石衬底（PSS）的技术引起了广泛的关注。湿法刻蚀行为和晶体蓝宝石工艺对于PSS应用以提高发光二极管的性能至关重要。这项研究调查了湿蚀刻过程中晶体蓝宝石中c- {0001}面上的空洞的形状演变行为和相关的动力学。结果表明，湿法刻蚀降低了腔的长径比，腔的形状是由c- {0001}，r- {1$\overline{\mathrm{1个}}$02}，p- {11$\overline{2}$3}，m- {10$\overline{\mathrm{1个}}$0}和s- {1$\overline{\mathrm{1个}}$01}家庭。证明了恒定的蚀刻速率，表明了蚀刻的逐步流动机理。如在蚀刻过程中遵循的阿伦尼乌斯动力学模型所阐明的那样，通过预先形成空腔来降低晶体蓝宝石的蚀刻活化能。这项研究为晶体蓝宝石的湿法刻蚀行为提供了新的见识，并可能为制造具有大纵横比图案的蓝宝石衬底开辟一条途径。