Two-dimensional analysis of spurious modes in aluminum nitride film resonators

Abstract

In this paper, a hybrid method, which combines the traditional concept of guided waves and the finite element method (FEM), is proposed to analyze the spurious modes of aluminum nitride (AlN) film with electrodes. First, the guided wave modes in the plated area are obtained by 1-D FEM. Second, a mode-match method is used to satisfy the boundary conditions. The vibration of the film resonator is a superposition of all of the guided modes. With respect to an AlN film resonator, which is a thicknessstretch mode resonator, we have identified three families of spurious modes: extension, thickness-stretch, and thicknessshear. The spectrum of spurious modes is calculated and the influence of the spurious modes is discussed.

Analytical and numerical modeling of resonant piezoelectric devices in China-A review

“…Dispersion relations and frequency spectra of modes in an AlN film resonator were obtained in refs. [74,75]. Energy trapping of TSh and TSt modes in plate resonators was reviewed in ref.…”

Trapped-Energy Thickness-Extensional Mode of a Partially Electroded ZnO Thin-Film Resonator

“…Up to now, the theoretical explanation of the energy-trapping effect has been reported in detail and sufficiently for ordinary piezoelectric plates. However, for piezoelectric thin-film resonators, similar theoretical results are still few and scattered [19], [20], let alone the relevant analysis of the trapped-energy vibration modes.…”