Lithium Niobate MEMS Antisymmetric Lamb Wave Resonators with Support Structures

Area of Science:

• Materials Science
• Electrical Engineering
• Acoustic Devices

Background:

• Single-crystal lithium niobate (LiNbO3) is ideal for bulk acoustic wave resonators due to its high electromechanical coupling and low losses.
• Existing LiNbO3 first-order antisymmetric (A1) Lamb mode resonators suffer from poor mechanical stability, limited power handling, and spurious modes.
• These limitations hinder the widespread application of LiNbO3-based Lamb mode resonators.

Purpose of the Study:

• To present an innovative design for A1 Lamb mode resonators using LiNbO3 thin films.
• To address the challenges of mechanical instability, limited power capacity, and spurious modes in current designs.
• To enhance the overall performance and applicability of LiNbO3 Lamb mode resonators.

Main Methods:

• Development of a novel resonator design incorporating a support-pillar structure.
• Integration of support pillars to facilitate spurious wave energy dissipation into the substrate.
• Anchoring the piezoelectric LiNbO3 thin film to a supportive framework.

Main Results:

• The support-pillar structure effectively mitigates unwanted spurious modes by dissipating wave energy.
• The novel design significantly enhances the mechanical stability of the LiNbO3 thin film.
• Improved heat dissipation capabilities of the core resonator structure are achieved.

Conclusions:

• The proposed support-pillar design offers a viable solution to overcome the limitations of conventional LiNbO3 A1 Lamb mode resonators.
• This innovation leads to resonators with improved spurious mode suppression, enhanced mechanical robustness, and better thermal management.
• The findings pave the way for broader applications of high-performance LiNbO3-based acoustic wave devices.