Solidly Mounted Scandium Aluminum Nitride on Acoustic Bragg Reflector Platforms at 14–20 GHz
This article reports the first groups of low-loss acoustic solidly mounted resonators (SMRs) and acoustic delay lines (ADLs) at 14-20 GHz. Bulk acoustic waves (BAWs) are confined in thin-film scandium aluminum nitride (ScAlN) on top of dielectric acoustic Bragg reflectors, consisting of alternating silicon dioxide with tantalum pentoxide (Ta2O5/SiO ${}_{{2}}\text {)}$ or niobium pentoxide (Nb2O5/SiO ${}_{{2}}$ ) on Si carrier wafers. Stack material parameters are extracted via high-resolution X-ray diffraction (HRXRD) and X-ray reflectivity (XRR). The simulation and experiment show confinement for longitudinal BAW from 14 to 20 GHz. ADLs show high propagation Q above 478 and 171 for Ta2O5/SiO2 and Nb2O5/SiO2, respectively. SMRs in both stacks perform similarly, showing coupling coefficient ( ${k}^{{2}}\text {)}$ of 2.0%, series Q ( ${Q}_{s}\text {)}$ of 156, and parallel Q ( ${Q}_{p}\text {)}$ values of 140 for Ta2O5/SiO2, while ${k}^{{2}}$ of 2.4%, ${Q}_{s}$ of 140, and ${Q}_{p}$ of 109 for Nb2O5/SiO2, both at 18.6 GHz. Upon development, ScAlN solidly mounted platforms will enable signal processing elements with better power handling.
Authors
- Sinwoo Cho
- 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)
- Joshua Campbell (ORCID: https://orcid.org/0009-0008-7057-1171)
- 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)
- Jack Kramer (ORCID: https://orcid.org/0000-0002-8078-8138)
- 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)
- The University of Texas at Austin (US)
Publication Details
- Journal
- IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control
- Published
- 2025-03-26
- DOI
- https://doi.org/10.1109/tuffc.2025.3554597
- Citations
- 4
- Primary Topic
- Acoustic Wave Resonator Technologies
- Type
- article
- Field-Weighted Citation Impact
- 2.70
Funders
- Defense Advanced Research Projects Agency