Elastic wave device and method for manufacturing the same
AssigneeMurata Manufacturing Co., Ltd.
InventorsMunehisa Watanabe, Hideki Iwamoto, Hajime Kando, Syunsuke Kido
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Abstract
An elastic wave device includes a supporting substrate, a high-acoustic-velocity film stacked on the supporting substrate and in which an acoustic velocity of a bulk wave propagating therein is higher than an acoustic velocity of an elastic wave propagating in a piezoelectric film, a low-acoustic-velocity film stacked on the high-acoustic-velocity film and in which an acoustic velocity of a bulk wave propagating therein is lower than an acoustic velocity of a bulk wave propagating in the piezoelectric film, the piezoelectric film is stacked on the low-acoustic-velocity film, and an IDT electrode stacked on a surface of the piezoelectric film.
Claims26
An elastic wave device including a piezoelectric film, the elastic wave device comprising:
- a high-acoustic-velocity supporting substrate in which an acoustic velocity of a bulk wave propagating therein is higher than an acoustic velocity of an elastic wave propagating in the piezoelectric film;
- a low-acoustic-velocity film stacked on the high-acoustic-velocity supporting substrate, in which an acoustic velocity of a bulk wave propagating therein is lower than an acoustic velocity of a bulk wave propagating in the piezoelectric film;
- the piezoelectric film stacked on the low-acoustic-velocity film;
- and
- an IDT electrode disposed on a surface of the piezoelectric film;
- wherein
- a thickness of the low-acoustic-velocity film stacked on the high-acoustic-velocity supporting substrate and disposed under the piezoelectric film is in a range of about 0.1λ to about 0.5λ where λ is a wavelength of an elastic wave determined by an electrode period of the IDT electrode.
An elastic wave device including a piezoelectric film, the elastic wave device comprising:
- a supporting substrate;
- a high-acoustic-velocity film disposed on the supporting substrate, in which an acoustic velocity of a bulk wave propagating therein is higher than an acoustic velocity of an elastic wave propagating in the piezoelectric film;
- a low-acoustic-velocity film stacked on the high-acoustic-velocity film, in which an acoustic velocity of a bulk wave propagating therein is lower than an acoustic velocity of a bulk wave propagating in the piezoelectric film;
- the piezoelectric film stacked on the low-acoustic-velocity film;
- and
- an IDT electrode disposed on a surface of the piezoelectric film;
- wherein
- a thickness of the low-acoustic-velocity film stacked on the high-acoustic-velocity film and disposed under the piezoelectric film is in a range of about 0.1λ to about 0.5λ, where λ is a wavelength of an elastic wave determined by an electrode period of the IDT electrode.
An elastic wave device including a piezoelectric film, the elastic wave device comprising:
- a high-acoustic-velocity supporting substrate which includes at least one among aluminum nitride, aluminum oxide, silicon carbide, silicon nitride, silicon oxynitride, a DLC film, and diamond;
- a low-acoustic-velocity film stacked on the high-acoustic-velocity supporting substrate which includes at least one among silicon oxide, glass, silicon oxynitride, tantalum oxide, and any material obtained by adding fluorine, carbon, or boron to silicon oxide;
- the piezoelectric film stacked on the low-acoustic-velocity film which includes at least one among LiTaO3, LiNbO3, ZnO, AlN and PZT;
- and
- an IDT electrode disposed on a surface of the piezoelectric film;
- wherein
- a thickness of the low-acoustic-velocity film stacked on the high-acoustic-velocity supporting substrate and disposed under the piezoelectric film is in a range of about 0.1λ to about 0.5λ;
- and
- where λ is a wavelength of an elastic wave determined by an electrode period of the IDT electrode.
An elastic wave device including a piezoelectric film, the elastic wave device comprising:
- a supporting substrate;
- a high-acoustic-velocity film disposed on the supporting substrate which includes at least one among aluminum nitride, aluminum oxide, silicon carbide, silicon nitride, silicon oxynitride, a DLC film, and diamond;
- a low-acoustic-velocity film stacked on the high-acoustic-velocity film which includes at least one among silicon oxide, glass, silicon oxynitride, tantalum oxide, and any material obtained by adding fluorine, carbon, or boron to silicon oxide;
- the piezoelectric film stacked on the low-acoustic-velocity film which includes at least one among LiTaO3, LiNbO3, ZnO, AlN and PZT;
- and
- an IDT electrode disposed on a surface of the piezoelectric film;
- wherein
- a thickness of the low-acoustic-velocity film stacked on the high-acoustic-velocity film and disposed under the piezoelectric film is in a range of about 0.1λ to about 0.5λ;
- and
- where λ is a wavelength of an elastic wave determined by an electrode period of the IDT electrode.
Dependencies are inferred from the claim text.