A piezoelectric thin film resonator having a stabilized temperature characteristic
of resonant frequency, a method for manufacturing the same, and a communication
apparatus using the piezoelectric thin film resonator are provided. The piezoelectric
thin film resonator is provided with a substrate having an opening, first and second
insulation films which are provided on one surface of the substrate while covering
the opening and which primarily include SiO2 and Al2O3,
respectively, Al2O3 having oxygen defect and being in an
amorphous state, and a piezoelectric thin film which is provided on the second
insulation film and is sandwiched between electrodes and which primarily includes ZnO.