Scandium-Doped Aluminum Nitride for Acoustic Wave Resonators, Filters, and Ferroelectric Memory Applications

Scandium-doped aluminum nitride (AlScN) has generated great research interest owing to its unique properties. The wurtzite-structure AlScN is compatible with the complementary metal oxide semiconductor (CMOS) process and has improved piezoelectricity compared with undoped aluminum nitride (AlN), making it a promising candidate to be used for next-generation radio frequency (RF) microelectromechanical system (MEMS) building blocks. Additionally, the ferroelectricity observed in AlScN can be potentially applied to ferroelectric memory devices. In this spotlight article, we provide a brief introduction of AlScN and summarize the recent progress of AlScN-based applications, including RF acoustic wave resonators, filters, and ferroelectric memory devices. Finally, the current challenges as well as the future opportunities of AlScN materials and related applications are discussed.