Patent attributes
A surface acoustic wave device utilizing a Rayleigh wave includes a LiNbO3 substrate having Euler angles of (0°±5°, θ±5°, 0°±10°), an electrode which is disposed on the LiNbO3 substrate and which includes an IDT electrode primarily including Au, a first silicon oxide film disposed in a region other than the region in which the above-described electrode is disposed, the first silicon oxide film having a film thickness substantially equal to the thickness of the above-described electrode, and a second silicon oxide film arranged to cover the electrode and the first silicon oxide film, wherein the film thickness of the electrode is in the range of about 0.062λ to about 0.14λ, where λ represents the wavelength of a surface acoustic wave, and θ of the above-described Euler angles of (0°±5°, θ±5°, 0°±10°) is in the range satisfying the following Formula (1):θ=31.72−206.92×exp(−1×TAu/0.0138) Formula (1)where TAu is a value of Au electrode film thickness normalized with the wavelength λ.
