In the past decade, aluminum scandium nitride (AlScN) with a high Sc content has shown ferroelectric properties, which provides a new option for CMOS-process-compatible ferroelectric memory, sensors and actuators, as well as tunable devices. In this paper, the ferroelectric properties of $A{l}_{0.7}S{c}_{0.3}N$ grown on different metals were studied. The effect of metal and abnormal orientation grains (AOGs) on ferroelectric properties was observed. A coercive field of approximately 3 MV/cm and a large remanent polarization of more than 100 μC/cm² were exhibited on the Pt surface. The $A{l}_{0.7}S{c}_{0.3}N$ thin film grown on the Mo metal surface exhibited a large leakage current. We analyzed the leakage current of $A{l}_{0.7}S{c}_{0.3}N$ during polarization with the polarization frequency, and found that the $A{l}_{0.7}S{c}_{0.3}N$ films grown on either Pt or Mo surfaces have large leakage currents at frequencies below 5 kHz. The leakage current decreases significantly as the frequency approaches 10 kHz. The positive up negative down (PUND) measurement was used to obtain the remanent polarization of the films, and it was found that the remanent polarization values were not the same in the positive and negative directions, indicating that the electrode material has an effect on the ferroelectric properties.

In this work, the dual-axis resonant micro-mirrors based on the 128°Y-cut lithium niobate on insulator (LNOI) have been experimentally demonstrated for the first time. We pioneered the utilization of the anisotropy of lithium niobate materials to simplify the control of micro-mirrors. Two pairs of e 16 torsional actuators are used to drive torsion mode and rocking mode, respectively. High electro-mechanical coupling factor ${K^2}_{16}$ in two orthogonal in-plane directions is required to achieve dual-axis actuation. The frequencies of the torsion mode and rocking mode are up to 60.034 kHz and 205.347 kHz, respectively. The corresponding optical angles of torsion mode and rocking mode are 13.04° and 9.16° in the air when the drive voltage is 10 V PP . Our work provides a novel solution for dual-axis piezoelectric MEMS micro-mirrors, which is promising for application in miniaturized optical systems.