Design, Optimization and Performance Assessment of Single Port Film Bulk Acoustic Resonator through Finite Element...

Area of Science:

• Materials Science
• Electrical Engineering
• Acoustic Devices

Background:

• Acoustic resonators are crucial for sensing applications.
• Enhancing resonator performance requires advanced materials and fabrication.
• Zinc Oxide (ZnO) is a promising piezoelectric material for acoustic devices.

Purpose of the Study:

• To design, simulate, and fabricate a single-port-cavity-based acoustic resonator for gas sensing.
• To investigate the performance enhancement of the acoustic resonator through Finite Element Analysis (FEA).
• To characterize the structural and surface properties of the deposited ZnO piezoelectric layer.

Main Methods:

• Finite Element Analysis (FEA) with frequency domain analysis for performance optimization.
• X-ray Diffraction (XRD) and Atomic Force Microscopy (AFM) for material characterization.
• Fabrication using bulk micromachined oxide (SiO2) for a thin membrane support.
• Radio Frequency (RF) measurements using a vector network analyzer (Anritsu MS2028C).

Main Results:

• Deposited ZnO film exhibits a single crystalline nature with a dominant (002) phase.
• AFM reveals a smooth surface and small grain size for the piezoelectric film.
• Successfully fabricated acoustic resonator operates at 1.84 GHz.
• Achieved a quality factor (Q) of 214 and an effective electromechanical coupling coefficient of 10.57%.

Conclusions:

• The fabricated acoustic resonator demonstrates excellent performance for gas sensing applications.
• The combination of FEA, optimized ZnO deposition, and micromachining is effective.
• The achieved Q factor and electromechanical coupling coefficient highlight the potential of this device.