THIN-FILM PIEZOELECTRIC BULK WAVE RESONATOR AND ITS MANUFACTURING METHOD, AND THIN-FILM PIEZOELECTRIC BULK WAVE RESONATOR FILTER USING THIN-FILM PIEZOELECTRIC BULK WAVE RESONATOR

摘要

PROBLEM TO BE SOLVED: To provide a thin-film piezoelectric bulk wave resonator which can realize energy confinement structure which can minimize a leakage path of bulk elastic wave to a substrate, and a high-frequency filter using it and its manufacturing method.

SOLUTION: A thin-film piezoelectric bulk wave resonator includes a lamination structure comprising a piezoelectric thin film and a first metallic electrode film and a second metallic electrode film holding at least a part of the piezoelectric thin-film therebetween. The first metallic electrode film is formed dispersed to an electrode surface opposite to the second metallic electrode film. The thin-film piezoelectric bulk wave resonator includes a void part on a substrate in a position corresponding to the lamination structure. The piezoelectric thin film, the first metallic electrode film and the second metallic electrode film, excepting a region of a wiring electrode electrically connected to the first metallic electrode film and a region of a wiring electrode electrically connected to the second metallic electrode film, are held in the air without coming into contact with an insulating substrate and a column is installed in the void part for supporting the lamination structure.

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