ELASTIC WAVE DEVICE AND METHOD FOR MANUFACTURING THE SAME

摘要

PROBLEM TO BE SOLVED: To expand a selection range of a mass-addition film material or an adjustable range of a resonance frequency.

SOLUTION: An elastic wave device includes a piezoelectric thin film resonator. The piezoelectric thin film resonator includes: a substrate 10; a piezoelectric thin film 14 formed on the substrate 10; lower and upper electrodes 12 and 16 formed so as to sandwich at least a part of the piezoelectric thin film 14; a resonance region 50 where the lower electrode 12 and the upper electrode 16 face each other while sandwiching the piezoelectric thin film 14 therebetween; and a first addition film 28 formed in the resonance region 50 between the piezoelectric thin film 14 and the upper electrode 16 and having a shape different from the resonance region 50.

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