Lithium niobate/lithium tantalate single-crystal thin films for post-moore era chip applications

Lithium niobate (LiNbO 3 ) and lithium tantalate (LiTaO 3 ) are a class of multifunctional materials with excellent piezoelectric/ferroelectric, electro-optic, and nonlinear optical properties, which have wide applications in high-performance radio frequency filters, optical communications, integrated photonics, quantum information, and other fields. With the advent of the post-Moore era of integrated circuit technology, LiNbO 3 /LiTaO 3 thin-film also shows great potential and advantages in new concept chip applications. High-quality single-crystal thin films lay the foundation for high-performance radio frequency, optoelectronic, and quantum devices and their integration. This review first introduces the main characteristics of LiNbO 3 /LiTaO 3 single-crystal thin films, such as ferroelectricity, piezoelectricity, electro-optic effect and nonlinear optical effect, then introduces the preparation methods of LiNbO 3 /LiTaO 3 single-crystal thin films represented by smart-cut and their application progress in different fields such as waveguides, modulators, laterally excited bulk acoustic wave resonators, and quantum devices. The application prospects and challenges of LiNbO 3 /LiTaO 3 single-crystal thin films in post-Moore era chips are also discussed in this article, aiming to provide valuable references for their development and application.