Low-Temperature Layer-by-Layer Epitaxy of Ferroelectric Al <sub>0.63</sub> Sc <sub>0.37</sub> N Thin Films for Back-End-of-Line Integration
Sc-doped aluminum nitride ((Al,Sc)N) is a promising material for next-generation nonvolatile memory and MEMS applications for its robust ferroelectricity and CMOS compatibility. However, the large coercive field remains the roadblock. Acquiring high Sc content-doped (Al,Sc)N epitaxial thin films is essential to reduce the coercive field but remains challenging, especially at low temperature for back-end-of-line (BEOL) integration. Here we demonstrate the layer-by-layer epitaxial growth of ferroelectric Al<sub>0.63</sub>Sc<sub>0.37</sub>N thin films (highest Sc content in epitaxial films) at 400 °C by developing a nitrogen-plasma-assisted pulsed laser deposition (N-PLD) technique. Verified by X-ray photoelectron spectroscopy analysis, the atomic nitrogen atmosphere is crucial to suppress nitrogen vacancies and stabilize the high Sc content (Al,Sc)N wurtzite phase. The high-quality epitaxial Al<sub>0.63</sub>Sc<sub>0.37</sub>N thin films show high remanent polarization >160 μC cm<sup>-2</sup> and desirable low coercive field of ∼2.9 MV cm<sup>-1</sup>. Our results open a new pathway for high-quality (Al,Sc)N BEOL integration for nonvolatile memory and MEMS applications.
Authors
- Mingqiang Cheng
- Dirui Wu
- Changjian Li (ORCID: https://orcid.org/0000-0002-5779-7466)
- Jiangyu Li (ORCID: https://orcid.org/0000-0003-0533-1397)
- Zihao Lin
- Shuhua Ma
- Weinan Chen (ORCID: https://orcid.org/0009-0009-5233-6247)
- Z. S. Zou
- Chao Li
Institutions
- ON Semiconductor (United States) (US)
- Harbin Institute of Technology (CN)
- Southern University of Science and Technology (CN)
- Global Communication Semiconductors (United States) (US)
Publication Details
- Journal
- Nano Letters
- Published
- 2025-11-05
- DOI
- https://doi.org/10.1021/acs.nanolett.5c04014
- Citations
- 1
- Primary Topic
- Acoustic Wave Resonator Technologies
- Type
- article
- Field-Weighted Citation Impact
- 0.67