THIN-FILM PIEZOELECTRIC RESONATOR AND MANUFACTURING METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide a thin-film piezoelectric resonator which has a good trapping property for distortion energy of an elastic wave and has a low electric resistance and is superior in suppression of oxidation or in adhesive property.

SOLUTION: The thin-film piezoelectric resonator includes a substrate; a lower electrode which has at least a part held in a hollow state, with respect to the substrate; a piezoelectric film provided on the lower electrode; and an upper electrode provided on the piezoelectric film. At least one of the lower electrode or the upper electrode that consists essentially of copper (Cu) and contains a second element the oxide formation free energy (ΔG) which is negatively larger than that of copper.

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