학술논문
6.9 GHz Film Bulk Acoustic Resonator based on Pulsed Laser Deposited LiNbO3 Film
Document Type
Conference
Author
Source
2023 IEEE International Ultrasonics Symposium (IUS) Ultrasonics Symposium (IUS), 2023 IEEE International. :1-4 Sep, 2023
Subject
Language
ISSN
1948-5727
Abstract
In this work, 200 nm-thick LiNbO 3 layers have been grown on Ru/Si and Pt/Si substrates using an industrialized Pulsed Laser Deposition (PLD) system. Film’s properties have been investigated by means of X-Ray Diffraction (XRD), Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), and Secondary Ions Mass Spectrometry (SIMS). In both cases, XRD analysis highlights the coexistence of LiNbO 3 phase and a Li-deficient secondary phase (LiNb 3 O 8 ). A c-axis preferential growth orientation have been obtained for LiNbO 3 film deposited on Pt/Si substrate. The formation of the Li-deficient secondary phase is related to Li diffusion, as highlighted by SIMS measurements. Finally, the fabricated Film Bulk Acoustic Resonator (FBAR) testifies to the piezoelectric activity of the as-deposited LiNbO 3 film. The FBAR based on pulsed laser deposited LiNbO 3 film displays an electromechanical coupling coefficient close to 6.7% at 6.9 GHz. Process optimizations (electrodes, piezoelectric films) are in progress in order to improve the microstructural properties of the as-deposited LiNbO 3 layer and thus the quality factor.