*Article* **Characterization of Ferroelectric** *Al***0.7***Sc***0.3***N* **Thin Film on Pt and Mo Electrodes**

**Ran Nie 1,† , Shuai Shao 1,2,3,† , Zhifang Luo 1,2,3 , Xiaoxu Kang <sup>4</sup> and Tao Wu 1,2,3,\***


**Abstract:** 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 *Al*0.7*Sc*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/cm<sup>2</sup> were exhibited on the Pt surface. The *Al*0.7*Sc*0.3*N* thin film grown on the Mo metal surface exhibited a large leakage current. We analyzed the leakage current of *Al*0.7*Sc*0.3*N* during polarization with the polarization frequency, and found that the *Al*0.7*Sc*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.

**Keywords:** AlScN; ferroelectric; thin film; leakage current; PUND test
