Heterogeneous integration strategies are increasingly being employed to achieve more compact and capable electronics systems for multiple applications including space, electric vehicles, and wearable and medical devices. To enable new integration strategies, the growth and transfer of thin electronic films and devices, including III-nitrides, metal oxides, and 2D materials, using 2D boron nitride (BN)-on-sapphire templates are demonstrated. The van der Waals (vdW) BN layer, in this case, acts as a preferred mechanical release layer for precise separation at the substrate–film interface and leaves a smooth surface suitable for vdW bonding. A tensilely stressed Ni layer sputtered on top of the film induces controlled spalling fracture that propagates at the BN/sapphire interface. By incorporating controlled spalling, the process yield and sensitivity are greatly improved, owed to the greater fracture energy provided by the stressed metal layer relative to a soft tape or rubber stamp. With stress playing a critical role in this process, the influence of residual stress on detrimental cracking and bowing is investigated. Additionally, a back-end selected area lift-off technique is developed which allows for isolation and transfer of individual devices or arbitrary shapes.

中文翻译：

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使用范德华释放层的电子薄膜的剥落诱导剥离和转移

越来越多地采用异构集成策略来为多种应用实现更紧凑和功能更强大的电子系统，包括空间、电动汽车、可穿戴和医疗设备。为了实现新的集成策略，演示了使用 2D 氮化硼 (BN) 蓝宝石模板来生长和转移薄电子薄膜和器件，包括 III 族氮化物、金属氧化物和 2D 材料。在这种情况下，范德华 (vdW) BN 层充当优选的机械释放层，用于在基板 - 薄膜界面处进行精确分离，并留下适合 vdW 键合的光滑表面。溅射在薄膜顶部的受拉应力的 Ni 层会引起受控的剥落断裂，该断裂在 BN/蓝宝石界面处传播。通过结合受控剥落，由于与软胶带或橡皮图章相比，受力金属层提供了更大的断裂能量，因此工艺产量和灵敏度得到了极大的提高。由于应力在此过程中起关键作用，因此研究了残余应力对有害开裂和弯曲的影响。此外，还开发了后端选定区域剥离技术，该技术允许隔离和转移单个设备或任意形状。