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 (TE) bulk acoustic wave (BAW) 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.
@article{arxiv.2510.11994,
title = {62.6 GHz ScAlN Solidly Mounted Acoustic Resonators},
author = {Yinan Wang and Byeongjin Kim and Nishanth Ravi and Kapil Saha and Supratik Dasgupta and Vakhtang Chulukhadze and Eugene Kwon and Lezli Matto and Pietro Simeoni and Omar Barrera and Ian Anderson and Tzu-Hsuan Hsu and Jue Hou and Matteo Rinaldi and Mark S. Goorsky and Ruochen Lu},
journal= {arXiv preprint arXiv:2510.11994},
year = {2026}
}