Aluminum-Nitride-Based Semiconductors: Growth Processes, Ferroelectric Properties, and Performance Enhancements

Aluminum nitride (AlN)-based ferroelectric films offer significant advantages, including compatibility with CMOS back-end processes, potential for sustainable miniaturization, and intrinsic stability in the ferroelectric phase. As promising emerging materials, they have attracted considerable attention for their broad application potential in nonvolatile ferroelectric memories. However, several key scientific and technological challenges remain, including the preparation of single-crystal materials, epitaxial growth, and doping, which hinder their progress in critical ferroelectric devices. To accelerate their development, further research is needed to elucidate the underlying physical mechanisms, such as growth dynamics and ferroelectric properties. This paper provides a comprehensive review of the preparation methods of AlN-based ferroelectric films, covering AlN, Al_1−xSc_xN, Al_1−xB_xN, Y_xAl_1−xN, and Sc_xAl_yGa_1−x−yN. We systematically analyze the similarities, differences, advantages, and limitations of various growth techniques. Furthermore, the ferroelectric properties of AlN and its doped variants are summarized and compared. Strategies for enhancing the ferroelectric performance of AlN-based films are discussed, with a focus on coercive field regulation under stress, suppression of leakage current, fatigue mechanism, and long-term stability. Then, a brief overview of the wide range of applications of AlN-based thin films in electronic and photonic devices is presented. Finally, the challenges associated with the commercialization of AlN-based ferroelectrics are presented, and critical issues for future research are outlined. By synthesizing insights on growth methods, ferroelectric properties, enhancement strategies, and applications, this review aims to facilitate the advancement and practical application of AlN-based ferroelectric materials and devices.