SURFACE ACOUSTIC WAVE DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a surface acoustic wave device which shows an excellent operating characteristic in a high frequency range by attaining a satisfactory propagation velocity V and frequency temperature characteristic TCF and also attaining an improved propagation loss. SOLUTION: An interdigital electrode having thickness t3 is formed on a diamond layer, and a ZnO layer having the polycrystal C axis orientation is formed over the interdigital electrode on the diamond layer with thickness t1 (t1 /t3 >=10). Furthermore, an SiO2 layer of thickness t2 is formed on the ZnO layer. The wavelengthλof the surface acoustic wave of the 0-order mode is set within ABCDEFA in regard of kh1=(2πt1 /λ) and kh2=(2πt2 /λ).