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 multi-functionalization applications, overcoming the limitations of epitaxial substrate materials. Benefiting from the abundant and exceptional electrical and photoelectrical properties of III-nitrides, 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.