| 摘要 |
PROBLEM TO BE SOLVED: To provide a surface acoustic wave device including an insulating film formed on a piezoelectric substrate to cover an IDT electrode, and having excellent frequency characteristics such as the resonance characteristics or the filter characteristics.SOLUTION: A surface acoustic wave device 1 includes a piezoelectric substrate 10, an IDT electrode 11, an insulating film 16 formed to cover the IDT electrode 11, and a frequency adjustment film 17 formed on the insulating film 16. On the surface 16a of the insulating film 16, a plurality of protrusions 16a1 having a shape corresponding to that of a plurality of electrode fingers 12a, 13a are formed. The position of the center of a protrusion 16a1 formed on the surface 16a of the insulating film 16 in the acoustic surface wave propagation direction D is different, in the acoustic surface wave propagation direction D, from the position of the center of the electrode fingers 12a, 13a corresponding to the protrusion 16a1 in the acoustic surface wave propagation direction D. |
