Chen, L., Wang, Q., Liu, C., Li, M., Song, W., Wang, W., Loke, D. K., & Zhu, Y. (2024). Leakage Mechanism and Cycling Behavior of Ferroelectric Al0.7Sc0.3N. Materials, 17(2), 397. https://doi.org/10.3390/ma17020397
Abstract:
Ferroelectric scandium-doped aluminum nitride (Al1-xScxN) is of considerable research interest because of its superior ferroelectricity. Studies indicate that Al1-xScxN may suffer from a high leakage current, which can hinder further thickness scaling and long-term reliability. In this work, we systematically investigate the origin of the leakage current in Al0.7Sc0.3N films via experiments and theoretical calculations. The results reveal that the leakage may originate from the nitrogen vacancies with positively charged states and fits well with the trap-assisted Poole-Frenkel (P-F) emission. Moreover, we examine the cycling behavior of ferroelectric Al0.7Sc0.3N-based FeRAM devices. We observe that the leakage current substantially increases when the device undergoes bipolar cycling with a pulse amplitude larger than the coercive electric field. Our analysis shows that the increased leakage current in bipolar cycling is caused by the monotonously reduced trap energy level by monitoring the direct current (DC) leakage under different temperatures and the P-F emission fitting.
License type:
Attribution 4.0 International (CC BY 4.0)
Funding Info:
This research / project is supported by the Science and Engineering Research Council of A*STAR - Ferroelectric Aluminum Scandium Nitride (Al1-xScxN) Thin Films and Devices for mm-Wave and Edge Computing
Grant Reference no. : A20G9b0135