Piezoelectric thin film resonator, filter and duplexer
AssigneeTaiyo Yuden Co., Ltd.
InventorsShinji Taniguchi, Tokihiro Nishihara, Tsuyoshi Yokoyama, Takeshi Sakashita
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Abstract
A piezoelectric thin film resonator includes: a substrate; a piezoelectric film provided on the substrate; a lower electrode and an upper electrode that sandwich at least a part of the piezoelectric film and face with each other; and an inserted film that is inserted in the piezoelectric film, is provided on an outer circumference region in a resonance region in which the lower electrode and the upper electrode sandwich the piezoelectric film and face with each other, is not provided in a center region of the resonance region, and has a cutout in the resonance region.
Claims14
A piezoelectric thin film resonator comprising:
- a substrate;
- a piezoelectric film provided on the substrate;
- a lower electrode and an upper electrode that sandwich at least a part of the piezoelectric film and face with each other;
- and
- an inserted film that is inserted in the piezoelectric film, the inserted film being provided on an outer circumference region in a resonance region in which the lower electrode and the upper electrode sandwich the piezoelectric film and face with each other, and being not provided in a center region of the resonance region, the inserted film having a cutout in the resonance region at a side to which the lower electrode extends from the resonance region in a plan view.
A piezoelectric thin film resonator comprising:
- a substrate;
- a piezoelectric film provided on the substrate and including a first piezoelectric film and a second piezoelectric film provided on the first piezoelectric film;
- a lower electrode and an upper electrode that sandwich at least a part of the piezoelectric film and face with each other, the first piezoelectric film being provided on the lower electrode, the upper electrode being provided on the second piezoelectric film;
- and
- an inserted film that is inserted between the first piezoelectric film and the second piezoelectric film, the inserted film being provided on an outer circumference region in a resonance region in which the lower electrode and the upper electrode sandwich the piezoelectric film and face with each other, and being not provided in a center region of the resonance region, the inserted film having a cutout in the resonance region,
- wherein a distance between an inner circumference and an outer circumference of the insertion film in the resonance region and in a region in which the cutout is located is smaller than a distance between the inner circumference and the outer circumference of the insertion film in the resonance region and in a region in which the cutout is not located.
A piezoelectric thin film resonator comprising:
- a substrate;
- a piezoelectric film provided on the substrate;
- a lower electrode and an upper electrode that sandwich at least a part of the piezoelectric film and face with each other;
- and
- an inserted film that is inserted in the piezoelectric film, the inserted film being provided on an outer circumference region in a resonance region in which the lower electrode and the upper electrode sandwich the piezoelectric film and face with each other, and being not provided in a center region of the resonance region, the inserted film having a cutout in the resonance region,
- wherein the cutout is provided at a side to which the upper electrode extends from the resonance region in a first direction in a plan view and is located substantially on a virtual center line of a portion of the upper electrode that extends from the resonance region in the first direction,
- a width of the cutout in a direction perpendicular to the first direction is less than a width of said extended portion of the upper electrode.
Dependencies are inferred from the claim text.