Surface acoustic wave device on LiTaO3 substrate using primarily silver electrodes covered with SiO2 film

摘要

A surface acoustic wave device has a significantly improved frequency temperature characteristic due to the arrangement of a SiO₂ film on an IDT such that cracking in the SiO₂ film surface is prevented from occurring, desired characteristics are reliably achieved, the electromechanical coupling coefficients is increased, and the attenuation constant alpha is reduced. In the surface acoustic wave device, at least one IDT primarily including Ag is arranged on a 20° to 60°-rotated Y plate LiTaO₃ substrate, and the SiO₂ film is arranged on the LiTaO₃ substrate while covering the IDT.