Design and fabrication of zero-group-velocity Lamb wave resonator onto silicon nitride/aluminum nitride suspended membrane
Abstract
The propagation of the Lamb-like modes along an AlN/Si3N4 thin suspended membrane was simulated in order to exploit the zero group velocity (ZGV) resonant conditions, i.e. the frequencies where the mode group velocity vanishes while the phase velocity remains finite. A ZGV micro electroacoustic resonator employing only one interdigital transducer (IDT) and no reflectors was designed that is based on the propagation of the first quasi symmetric mode qS1 at frequency of about 1.63 GHz. The device was fabricated directly onto commercially available thin suspended Si3N4 membrane, 200 nm thick, in square silicon supporting frame (200 μm thick) The Cr/Au interdigital transducer (IDT), with periodicity of 10 μm, was fabricated by electron beam lithography (EBL) directly onto the Si3N4 membrane; then the piezoelectric AlN layer was grown onto the membrane at room temperature by rf reactive magnetron sputtering technique. The technological feasibility of the ZGV resonator on commercial Si3N4 suspended membrane is demonstrated and preliminary experimental results are shown.
- Publication:
-
Nanoinnovation 2017
- Pub Date:
- July 2018
- DOI:
- 10.1063/1.5047767
- Bibcode:
- 2018AIPC.1990b0013C