| 摘要 |
PROBLEM TO BE SOLVED: To set different temperature characteristics and different resonance characteristics for each resonator.SOLUTION: An acoustic wave device includes a piezoelectric thin film resonator including: a substrate 10; a lower electrode 12 formed on the substrate; a piezoelectric film 14 having at least two layers and formed on the lower electrode; an insulation film 28 sandwiched by the piezoelectric film having the two layer; and an upper electrode 16 formed on the piezoelectric film having the two layers. In the piezoelectric thin film resonator, an area of the insulation film in a resonance region 50 where the upper electrode faces the lower electrode across the piezoelectric film is different from an area of the resonance region 50. |
