**4. Conclusions**

In this paper, we analyzed the correlation between the ferroelectricity of aluminum scandium nitride and bottom metal electrodes. On one hand, the difference in crystal orientation of films grown on Pt or Mo metals will affect the ferroelectric properties. On the other hand, the inherent contact barrier between metal and dielectric materials will also affect ferroelectricity. The direction of driving voltage and frequency will also lead to different phenomena. After solving the problem of the leakage current, the high remnant polarization of more than 100 µC/cm<sup>2</sup> and coercive field of 3 MV/cm exhibited by *Al*0.7*Sc*0.3*N* films with good quality are suitable for ferroelectric memory devices. In FeRAM or FeFET, a high remnant polarization value can increase the storage density, while a suitable coercivity field can meet the storage window at a thin thickness. With further development, AlScN is expected to be widely used in commercial memory devices, as well as tunable RF applications.

**Author Contributions:** R.N.: Conceptualization, validation, graphics, original draft preparation; S.S.: Methodology, formal analysis, review and editing; Z.L.: Investigation, data curation; X.K.: Supervision; T.W.: Supervision, project administration, editing. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by National Natural Science Foundation of China (61874073) and Lingang Laboratory under Grant LG-QS-202202-05.

**Data Availability Statement:** Data is available upon request.

**Acknowledgments:** The authors appreciate the device fabrication support from the ShanghaiTech Quantum Device Lab (SQDL), and Analytical Instrumentation Center (SPSTAIC10112914) XRD Lab.

**Conflicts of Interest:** The authors declare no conflict of interest.
