Acoustic wave device
AssigneeTaiyo Yuden Co., Ltd.
InventorsShinji Taniguchi, Tokihiro Nishihara
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Abstract
An acoustic wave device includes: a piezoelectric thin film resonator including: a substrate; a lower electrode formed on the substrate; at least two piezoelectric films formed on the lower electrode; an insulating film sandwiched by the at least two piezoelectric films; and an upper electrode formed on the at least two piezoelectric films, wherein an area of the insulating film within a resonance region, in which the lower electrode and the upper electrode face each other across the at least two piezoelectric films, is different from an area of the resonance region.
Claims20
An acoustic wave device comprising:
- a piezoelectric thin film resonator including:
- a substrate;
- a lower electrode formed on the substrate;
- at least two piezoelectric films formed on the lower electrode;
- an insulating film sandwiched by the at least two piezoelectric films;
- and
- an upper electrode formed on the at least two piezoelectric films, wherein
- an area of the insulating film within a resonance region, in which the lower electrode and the upper electrode face each other across the at least two piezoelectric films, is different from an area of the resonance region.
An acoustic wave device comprising:
- a piezoelectric thin film resonator including:
- a substrate;
- a lower electrode formed on the substrate;
- at least two piezoelectric films formed on the lower electrode;
- an insulating film sandwiched by the at least two piezoelectric films;
- and
- an upper electrode formed on the at least two piezoelectric films, wherein
- the insulating film within a resonance region, in which the lower electrode and the upper electrode face each other across the at least two piezoelectric films, has a concave portion and a convex portion.
An acoustic wave device comprising:
- a piezoelectric thin film resonator including:
- a substrate;
- a piezoelectric film located on the substrate;
- a lower electrode and an upper electrode that face each other across the piezoelectric film;
- a temperature compensation film having a temperature coefficient of elastic constant opposite in sign to a temperature coefficient of elastic constant of the piezoelectric film;
- and
- conductive films formed on an upper surface and a lower surface of the temperature compensation film, and mutually electrically short-circuited, wherein
- an area of the temperature compensation film within a resonance region, in which the lower electrode and the upper electrode facing each other across the piezoelectric film, is different from an area of the resonance region.
Dependencies are inferred from the claim text.