TY - GEN
T1 - Epitaxial Al0.77Sc0.23N SAW and Lamb Wave Resonators
AU - Park, Mingyo
AU - Ansari, Azadeh
N1 - Publisher Copyright:
© 2020 IEEE.
PY - 2020/7
Y1 - 2020/7
N2 - This work reports on surface acoustic wave (SAW) and the super high frequency (SHF) Lamb wave resonators (LWR) with reflective gratings based on 400 nm-thick epitaxial Aluminum Scandium Nitride (AlScN) piezoelectric films. The films are grown on silicon substrates by molecular beam epitaxy (MBE), with \text{Sc}/(\mathrm{A}1+\text{Sc}) ratio of 23%, which is the highest Sc concentration, reported to date for BAW/SAW resonators based on AlN epitaxial films. We first demonstrate a SAW resonator, with reflective gratings. The Si substrate of the SAW resonator is then removed from the backside, to form a suspended 400 nm-thick plate. A floating bottom metal electrode is deposited from the backside to enhance the effective electromechanical coefficient ({k_{eff}}^{2}) of the Lamb wave resonators. A high {k_{eff}}^{2} value of 7.45% at a resonant frequency of 4.92 GHz is reported in this work, yielding {k_{eff}}^{2}\times Q_{m} of 7.3. To the authors' knowledge, this work marks the highest {k_{eff}}^{2} achieved for >3GHz AlN-based Lamb wave resonators to date.
AB - This work reports on surface acoustic wave (SAW) and the super high frequency (SHF) Lamb wave resonators (LWR) with reflective gratings based on 400 nm-thick epitaxial Aluminum Scandium Nitride (AlScN) piezoelectric films. The films are grown on silicon substrates by molecular beam epitaxy (MBE), with \text{Sc}/(\mathrm{A}1+\text{Sc}) ratio of 23%, which is the highest Sc concentration, reported to date for BAW/SAW resonators based on AlN epitaxial films. We first demonstrate a SAW resonator, with reflective gratings. The Si substrate of the SAW resonator is then removed from the backside, to form a suspended 400 nm-thick plate. A floating bottom metal electrode is deposited from the backside to enhance the effective electromechanical coefficient ({k_{eff}}^{2}) of the Lamb wave resonators. A high {k_{eff}}^{2} value of 7.45% at a resonant frequency of 4.92 GHz is reported in this work, yielding {k_{eff}}^{2}\times Q_{m} of 7.3. To the authors' knowledge, this work marks the highest {k_{eff}}^{2} achieved for >3GHz AlN-based Lamb wave resonators to date.
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U2 - 10.1109/IFCS-ISAF41089.2020.9234850
DO - 10.1109/IFCS-ISAF41089.2020.9234850
M3 - Conference contribution
AN - SCOPUS:85096998934
T3 - IFCS-ISAF 2020 - Joint Conference of the IEEE International Frequency Control Symposium and IEEE International Symposium on Applications of Ferroelectrics, Proceedings
BT - IFCS-ISAF 2020 - Joint Conference of the IEEE International Frequency Control Symposium and IEEE International Symposium on Applications of Ferroelectrics, Proceedings
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 2020 Joint Conference of the IEEE International Frequency Control Symposium and IEEE International Symposium on Applications of Ferroelectrics, IFCS-ISAF 2020
Y2 - 19 July 2020 through 23 July 2020
ER -