Full-wave analysis of piezoelectric boundary waves propagating along metallic grating sandwiched between two semi-infinite layers

• Published in: IEEE transactions on ultrasonics, ferroelectrics, and frequency control Vol. 56; no. 4; pp. 806 - 811
• Main Authors: Yiliu Wang, Hashimoto, K.-y., Omori, T., Yamaguchi, M.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.04.2009; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Acoustic wave devices, piezoelectric and piezoresistive devices; Acoustic waves; Acoustics; Applied sciences; Boundaries; Boundary conditions; Computer Simulation; Copper; Diffraction gratings; Electrodes; Electronics; Equipment Design; Exact sciences and technology; Finite element analysis; Finite element method; Frequency; Fundamental areas of phenomenology (including applications); Gratings; Gratings (spectra); Impedance; Mathematical models; Metals; Micro-Electrical-Mechanical Systems - instrumentation; Models, Theoretical; Permittivity; Physics; Piezoelectricity; Power generation; Scattering, Radiation; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Stress; Studies; Substrates; Transducers; Ultrasonics, quantum acoustics, and physical effects of sound; Wave propagation; Acoustic wave device; Finite element method; Diffraction grating; Silicon oxides; Size effect; Lithium niobates; Sandwich structure; SH wave; Piezoelectric substrate; Isotropic material; Modeling; Spectral analysis
• ISSN: 0885-3010; 1525-8955
• DOI: 10.1109/TUFFC.2009.1103

This paper describes full-wave analysis of piezoelectric boundary acoustic waves (PBAWs) propagating along a metallic grating sandwiched between 2 semi-infinite layers. In the analysis, the finite element method (FEM) is used for the grating region while the spectral domain analysis (SDA) is applied for an isotropic overlay region as well as a piezoelectric substrate region. The combination of the FEM and SDA makes the numerical analysis very fast and precise. As an example, the analysis was made on the PBAWs propagating in an SiO 2 overlay/ Cu grating/rotated Y-cut LiNbO 3 structure. It is shown that both the shear-horizontal (SH) type and Rayleigh-type PBAWs are supported in the structure, and that their velocities are very close to each other. Thus spurious responses due to the Rayleigh-type PBAW should completely be suppressed for device implementation. Discussions are made in detail on the influence of Cu grating thickness, substrate rotation angle, and metallization ratio on excitation and propagation characteristics of the SH- and Rayleigh-type PBAWs.