Fig. 2: Device fabrication and SEM micrographs.

a, b Micro-machining process flow adopted to fabricate the devices reported in this work in both a a 3D and a b cross-sectional views. Despite representing a single nanoacoustic resonator, this process was also utilized to fabricate the filters. c–f SEM pictures of fabricated resonators and filters, with their relevant dimensions highlighted. c provides an overview of different resonators on the same chip. In d, a device with a λ of 933 nm and operating at 8.35 GHz is shown. The bending is due to residual stress-gradient in the film, quantified to be 0.9 GPa/μm. In e, a device with a λ of 560 nm and operating at 10.2 GHz is shown, while f depicts a first-order ladder filter with center frequency of 9.17 GHz.