62.6 GHz ScAlN solidly mounted acoustic resonators
We demonstrate a record-high 62.6 GHz solidly mounted acoustic resonator (SMR) incorporating a 67.6 nm scandium aluminum nitride (Sc0.3Al0.7N) piezoelectric layer on a 40 nm buried platinum (Pt) bottom electrode, positioned above an acoustic Bragg reflector composed of alternating SiO2 (28.2 nm) and Ta2O5 (24.3 nm) layers in 8.5 pairs. The Bragg reflector and piezoelectric stack above are designed to confine a third-order thickness-extensional bulk acoustic wave mode, while efficiently transducing with thickness-field excitation. The fabricated SMR exhibits an extracted piezoelectric coupling coefficient (k2) of 0.8% and a maximum Bode quality factor (Q) of 51 at 63 GHz, representing the highest operating frequency reported for an SMR to date. These results establish a pathway toward mmWave SMR devices for filters and resonators in next-generation RF front ends.
Authors
- Supratik Dasgupta (ORCID: https://orcid.org/0000-0001-5367-0540)
- Tzu-Hsuan Hsu (ORCID: https://orcid.org/0000-0003-4606-1039)
- Jue Hou (ORCID: https://orcid.org/0000-0002-9015-1827)
- Pietro Simeoni (ORCID: https://orcid.org/0000-0003-3612-3646)
- Lezli Matto (ORCID: https://orcid.org/0000-0002-5775-3703)
- Mark S. Goorsky (ORCID: https://orcid.org/0000-0002-3416-6688)
- Ian Anderson (ORCID: https://orcid.org/0009-0007-2570-3246)
- Omar Barrera (ORCID: https://orcid.org/0009-0003-6157-1069)
- Ruochen Lu (ORCID: https://orcid.org/0000-0003-0025-3924)
- Matteo Rinaldi (ORCID: https://orcid.org/0000-0003-0858-0786)
- Vakhtang Chulukhadze (ORCID: https://orcid.org/0009-0003-6869-1231)
- Yinan Wang (ORCID: https://orcid.org/0000-0002-1558-960X)
- Byeongjin Kim (ORCID: https://orcid.org/0009-0007-1007-0909)
- Nishanth Ravi (ORCID: https://orcid.org/0009-0008-2211-3264)
- Kapil Saha
- Eugene Kwon (ORCID: https://orcid.org/0000-0003-0722-4915)
Institutions
- Northeastern University (US)
- University of California, Los Angeles (US)
- Bühler (United Kingdom) (GB)
- The University of Texas at Austin (US)
Publication Details
- Journal
- Applied Physics Letters
- Published
- 2026-01-26
- DOI
- https://doi.org/10.1063/5.0306947
- Primary Topic
- Acoustic Wave Resonator Technologies
- Type
- article
- Field-Weighted Citation Impact
- 0.00