@inproceedings{a42ecf9ab87e41ff8618139faa91eb0a,
title = "A High-kt2 Switchable Ferroelectric Al0.7Sc0.3N Film Bulk Acoustic Resonator",
abstract = "This work demonstrates the hysteresis behavior and temperature characterization of an AlScN Film bulk acoustic resonator (FBAR) with ~30% Sc/(Al+Sc) ratio. Operating at ~3 GHz, the as-fabricated FBAR exhibits a record high effective electromechanical coupling ( kt 2 ) of 18% with a mechanical quality factor ( Qm) of 328. The polarization of the FBAR can be switched from N-polar to Al-polar by using a triangular-wave signal with a peak voltage of -350 V, applied for 6 seconds at 1 kHz across a 900 nm-thick Al 0.7 Sc 0.3 N film. It is shown that the polarization switching of AlScN film not only changes the polarity of the piezoelectric coefficient (e 33 ), but also changes the series resistance of the metal-ferroelectric-metal (MFM) stack and leads to an effective “switching” of the FBAR. The frequency response of the switchable FBAR is investigated after polarization switching during 4 cycles and at elevated temperatures up to 600 K.",
keywords = "Acoustic resonators, Aluminum Scandium Nitride, FBAR, Ferroelectric, Filters, Frequency tuning, Piezoelectric films",
author = "Jialin Wang and Mingyo Park and Stefan Mertin and Tuomas Pensala and Farrokh Ayazi and Azadeh Ansari",
note = "Funding Information: This work was supported by the National Science Foundation 1542174) and National Science Foundation CAREER Award 1944304). Funding Information: The sputtered piezo-stack Mo/Al0.7Sc0.3N/Mo was provided by VTT Technical Research Centre of Finland. The FBAR devices were fabricated at the Institute for Electronics and Nanotechnology (IEN) cleanroom facility at the Georgia Institute of Technology, a member of the National Nanotechnology Coordinated Infrastructure (NNCI), which is supported by the National Science Foundation (Grant ECCS-1542174). This work is supported by NSF CAREER award (ECCS-1944304). Publisher Copyright: {\textcopyright} 2020 IEEE.; Joint Conference of the IEEE International Frequency Control Symposium and IEEE International Symposium on Applications of Ferroelectrics, IFCS-ISAF 2020 : Online ; Conference date: 19-07-2020 Through 23-07-2020",
year = "2020",
month = oct,
day = "22",
doi = "10.1109/IFCS-ISAF41089.2020.9234831",
language = "English",
isbn = "978-1-7281-6753-4",
series = "Proceedings of the IEEE International Symposium on Applications of Ferroelectrics",
publisher = "IEEE Institute of Electrical and Electronic Engineers",
booktitle = "Joint Conference of the IEEE International Frequency Control Symposium and IEEE International Symposium on Applications of Ferroelectrics (IFCS-ISAF 2020)",
address = "United States",
}