Critical thickness of GaN film in controllable stress-induced self-separation for preparing native GaN substrates
Critical thickness of GaN film in controllable stress-induced self-separation for preparing native GaN substrates
复制标题
制备原生 GaN 衬底的可控应力诱导自分离 GaN 薄膜的临界厚度
DOI：
10.1016/j.matdes.2019.107985
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发表时间：
2019
影响因子：
8.4
通讯作者：
Zhang Guoyi
中科院分区：
文献类型：
--
作者：
Li Mengda;Cheng Yutian;Yu Tongjun;Wu Jiejun;He Jinmi;Liu Nanliu;Han Tong;Zhang Guoyi
应力诱导自分离是制备GaN衬底最有效的方法之一。GaN膜厚的控制是GaN膜与衬底完全分离的关键。考虑到双层膜的弯曲，我们研究了分离前GaN膜中的径向应力。提出了一个收缩的圆形脱层前缘模型，推导了分离后的未松弛应力，并研究了不同厚度的GaN/蓝宝石系统在整个分离过程中的能量释放率。确定了从蓝宝石衬底上分离2英寸（5.08 cm）GaN薄膜的临界厚度为500-700 μm。通过将GaN薄膜厚度精确控制在该临界厚度附近，完全分离率可提高到74%，这对实现GaN衬底的产业化具有重要意义。
Stress-induced self-separation is one of the most efficient process for preparing native GaN substrate. The control of GaN film thickness is the key point for GaN film separating from substrate completely. Considering the bowing of bilayer, we studied the radial stress in GaN film before separation. A shrunken circular delamination front model was proposed to derive the unrelaxed stress after separation, and the energy release rate for GaN/sapphire systems of different thicknesses was investigated during the whole separation process. A critical thickness about 500–700 μm was determined for separating 2-inch (5.08 cm) GaN film from a sapphire substrate. By precisely controlling the GaN film thickness around such critical thickness, the complete separation rate could be increased greatly to 74%, which is of great importance in realizing the industrialization of GaN substrate.