Abstract
The propagation of the Lamb-like modes along a diamond/AlN thin supported structure was simulated in order to exploit the intrinsic zero group velocity (ZGV) features to design high frequency electroacoustic resonators. As the ZGV points are associated with an intrinsic energy localization under the metal electrodes, acoustic micro-resonators can be designed that employ only one interdigital transducer (IDT) and no reflectors, thus reducing both the device size and technological complexity. The ZGV resonant conditions in the diamond/AlN composite plate, i.e., the frequencies where the mode group velocity vanishes while the phase velocity remains finite, were investigated in the frequency range from few hundreds of MHz up to 3500 MHz. Thin film bulk acoustic resonators (TFBARs) based on c-AlN and on 45° c-axis tilted AlN film on diamond suspended membrane were simulated that operate in longitudinal and shear mode: the former is a thickness-extensional mode, while the latter is a thickness-in plane-shear mode that is suitable for liquid sensing applications. A smart structure based on diamond/AlN composite suspended membrane was modelled that provides several integrated functions including sensing in gaseous and liquid environment, and stable frequency source.
Highlights
Increased devices operating frequency and reduced size are actual challenges in the field of electroacoustic devices development
Www.mdpi.com/journal/proceedings Proceedings 2018, 2, 133 acoustic resonators (TFBARs) based on c-axis oriented and 45° c-axis tilted AlN film on diamond was simulated that are based on the propagation of longitudinally and in plane-shear horizontally polarized modes, respectively; the former is suitable for sensing in gaseous environment while the latter is suitable for liquid sensing applications
A thin film bulk acoustic resonator (TFBAR) was supposed to be monolithically implemented on the same AlN/diamond suspended membrane consisting of a pair of metal electrodes (Pt 0.1 μm thick, and 350 μm × 350 μm the area) sandwiching the piezoelectric thin film, with AlN and diamond layers 3.6 and 10 μm thick
Summary
Increased devices operating frequency and reduced size are actual challenges in the field of electroacoustic devices development. The main objective of this paper consists in the modelling study of the Lamb modes propagation in the thin suspended composite membranes including an AlN layer 3.6 μm thick on top of a diamond suspended membrane 10 μm thick.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
