| 摘要 |
PROBLEM TO BE SOLVED: To provide an acoustic wave device that has a large electromechanical coupling coefficient or to suppress an acoustic wave device from increasing in size.SOLUTION: The present invention relates to an acoustic wave device having a piezoelectric film 26 formed of an aluminum nitride film containing a diad and a tetrad or a triad and a pentad, and a lower electrode 24 and an upper electrode 28 which excites an acoustic wave to be propagated in the piezoelectric film 26. The acoustic wave device includes: the piezoelectric film 26 which contains elements contributing to at least one of an increase in dielectric constant and slowing of an acoustic velocity; and the lower electrode 24 and upper electrode 28 which excite the acoustic wave to be propagated in the piezoelectric film 26, and has a resonance frequency of 1.5 GHz or lower. |
