Patent attributes
An acoustic wave device of the present application includes a piezoelectric substrate (14), interdigital transducer electrodes (13) formed on the piezoelectric substrate (14), and an SiO2 film (12) formed so as to cover the electrodes (13). The acoustic wave device also includes a displacement adjustment film (11) formed on the SiO2 film (12), and the displacement adjustment film (11) is formed from a substance whose acoustic velocity is slower than that of the substance forming the SiO2 film (12). According to this configuration, it is possible to suppress unnecessary waves as well as improve temperature characteristics. Also, by mounting such an acoustic wave device in a communication module or communication apparatus, it is possible to achieve an improvement in reliability.
