2025-12-25 東京科学大学
図1．さまざまな膜厚のPt下部電極を用いた場合の (Al,Sc)N膜の強誘電特性の比較。Pt下部電極を5 nmまで薄くしても(Al,Sc)N膜の強誘電性が劣化しなかった。
＜関連情報＞
- https://www.isct.ac.jp/ja/news/pceu6nh4xgos
- https://www.isct.ac.jp/plugins/cms/component_download_file.php?type=2&pageId=&contentsId=1&contentsDataId=2928&prevId=&key=e34630810f78c19d505198d2770b23df.pdf
- https://advanced.onlinelibrary.wiley.com/doi/10.1002/aelm.202500451
集積Pt/(Al 0.9 Sc 0.1 )N/Ptコンデンサスタックの厚さを30 nmまでスケーリング Thickness Scaling of Integrated Pt/(Al0.9Sc0.1)N/Pt Capacitor Stacks to 30 nm
Soshun Doko, Naoko Matsui, Toshikazu Irisawa, Koji Tsunekawa, Nana Sun, Yoshiko Nakamura, Kazuki Okamoto, Hiroshi Funakubo
Advanced Electronic Materials Published: 07 November 2025
DOI:https://doi.org/10.1002/aelm.202500451
Abstract
The total thickness scaling of electrodes and the (Al0.9Sc0.1)N layer is evaluated for ferroelectric memory applications. The good crystal orientation and large remanent polarization (Pr) above 100 µC cm−2 are obtained for 160-nm-thick (Al0.9Sc0.1)N films even when the Pt bottom electrode is reduced to a thickness of 5 nm. The (Al0.9Sc0.1)N film integrated on a 5-nm-thick Pt bottom electrode maintains a saturated Pr value above 100 µC cm−2 at a thickness of 30 nm. Furthermore, the (Al0.9Sc0.1)N film exhibits improved crystal orientation by the post-heat-treatment of the Pt bottom electrode, and a saturated large Pr value above 100 µC cm−2 is obtained at a thickness of 20 nm. Moreover, a Pr value of 90 µC cm−2 is obtained at a (Al0.9Sc0.1)N thickness of 10 nm. No significant degradation in the Pr characteristics is detected when the thickness of the Pt top electrode is reduced to 5 nm. Finally, the total thickness is successfully scaled down to 30 nm for a Pt (top electrode, 5 nm)/(Al0.9Sc0.1)N (20 nm)/Pt (bottom electrode, 5 nm) stack. This work presents guidelines for the thickness scaling of the (Al,Sc)N-based stacks for ferroelectric memory applications, including ferroelectric thin films and electrodes.
