To provide a thin film piezoelectric resonator which has small insertion loss.
Provided is the thin film piezoelectric resonator comprising: a substrate 12 having a recessed portion 11; a first electrode 13 formed on the substrate 12 to cover the recessed portion 11 and having a lead-out portion 13a for electric connection with the outside; a piezoelectric thin film 14 formed on the first electrode 13 inside the recessed portion 11; a second electrode 15 formed on the substrate 12 to cover the piezoelectric thin film 14 and having a lead-out portion 15a for electric connection with the outside; and a dielectric film 17 formed in an region 16 where at least the first electrode 13 and second electrode 15 overlap with each other outside the piezoelectric thin film 14 and having a lower dielectric constant than the piezoelectric thin film 14. The parasitic capacity of the region 16 where the first electrode 13 and second electrode 15 overlap with each other is reduced to obtain the thin film piezoelectric resonator 10 with small insertion loss.
MOTAI TAKAKO
SHIBATA HIRONOBU
