| 摘要 |
PROBLEM TO BE SOLVED: To suppress deterioration of properties and/or reduction of reliability.SOLUTION: A piezoelectric thin film resonator comprises: a substrate 10; a piezoelectric film 14 that is provided on the substrate; a lower electrode 12 and an upper electrode 16 that are opposite to each other with the piezoelectric film interposed therebetween; an insertion film 28 which is inserted into the piezoelectric film and provided in at least a part of an outer peripheral region 52 within a resonance region 50 and outside of the outer peripheral region and is not provided in a central region 54 of the resonance region; a protection film 24 that is formed on the upper electrode and the piezoelectric film; and wiring 20 that is connected to the lower electrode in a lead-out region 57 of the lower electrode. In the lead-out region of the lower electrode, an outer periphery of the insertion film is positioned outside of an outer periphery of the upper electrode and inside of an outer periphery of the piezoelectric film, an outer periphery of the protection film is positioned outside of the outer periphery of the insertion film, and the wiring covers the outer periphery of the protection film.SELECTED DRAWING: Figure 1 |
