III-nitride semiconductor membrane electronics and optoelectronics for heterogeneous integration

The rapidly developing III-nitrides materials and devices technologies are driving the advancements in hybrid heterogeneous structures for multi-material and multifunctional electronic or optoelectronic integrated systems. Beyond heteroepitaxial growth, the process integrations of freestanding thin-film devices open up more possibilities for high levels of integration and multifunctionalization applications, overcoming the limitations of epitaxial substrate materials. Benefiting from the abundant and exceptional electrical and photoelectrical properties of IIInitrides, the heterogeneous integration of thin-film devices significantly enhances the functional capabilities in the fields of on-chip optical communication, micro-LED display, and flexible sensing. In this review, we present a comprehensive overview of freestanding thin-film device fabrication technology and its integration strategies. We discuss the characteristics of both conventional and advanced III-nitride epilayer transfer technologies, focusing on lift-off, transfer, bonding, and integration process. Promising applications are summarized based on the integration technology of transferable III-nitride thin-film devices. Additionally, we analyze the remaining challenges in manufacturing and application of III-nitride thin-film devices for advanced heterogeneous integrations. The further development of these technologies will promote the research of III-nitrides in pioneering fields, including high-speed photoelectric integrated communication system, cost-effective Micro-LED display and reliable biosensing applications.