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.
|Series||Proceedings of the IEEE International Symposium on Applications of Ferroelectrics|
|Conference||Joint Conference of the IEEE International Frequency Control Symposium and IEEE International Symposium on Applications of Ferroelectrics, IFCS-ISAF 2020|
|Period||19/07/20 → 23/07/20|
- Acoustic resonators
- Aluminum Scandium Nitride
- Frequency tuning
- Piezoelectric films