Support Loss Evasion In Breathing-Mode High-Order Silicon Disc Resonators

Keywords

Bulk micro resonator; Disc resonator; PML modeling; Quality factor; Support loss

Abstract

In this paper, single crystalline silicon (SCS) anisotropy is exploited to suppress support loss in side-supported breathing-mode thin-film piezoelectric-on-silicon (TPoS) disc resonators for the first time. Contrary to the case of isotropic materials, for an SCS breathing-mode disc resonator, displacement is not uniform at the outer edges of the resonator. It is shown that for high order harmonics, there exists pseudo-nodal points at the side of the disc resonator body where tethers could be strategically placed achieving minimum acoustic energy leakage. A 3D model including a perfect matching layer (PML) is developed to simulate the support loss of side-supported disc resonators in COMSOL. Using this model, it is predicted that 8th-harmonic single-crystalline silicon disc resonators with tethers aligned to the [100] plane could achieve orders of magnitude smaller support loss compared to lower harmonics. TPoS disc resonators are fabricated on single crystalline silicon with tethers aligned to [100] and [110] crystalline planes. The frequency response of both types of resonators are measured and it is observed that: 1) for the resonator with tethers aligned to [100], unloaded quality factor improves from 433 for the second harmonic mode at 42 MHz to 9660 for the eighth harmonic mode at 195 MHz 2) the resonator with tethers aligned to [110] doesn't exhibit any notable resonance activity for mode numbers greater than 4 and for those low order harmonics the quality factors are all below 1000.

Publication Date

10-31-2017

Publication Title

IEEE International Ultrasonics Symposium, IUS

Document Type

Article; Proceedings Paper

Personal Identifier

scopus

DOI Link

https://doi.org/10.1109/ULTSYM.2017.8092348

Socpus ID

85039456990 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/85039456990

This document is currently not available here.

Share

COinS