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.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41190694.
- Also identified by DOI 10.1021/acs.nanolett.5c04014.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
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.