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US 12,224,733 B2Granted
Acoustic wave device
AssigneeMurata Manufacturing Co., Ltd.
InventorKatsuya Daimon
Life of this patent
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Abstract
An acoustic wave device includes a silicon support substrate, a silicon nitride film on the support substrate, a silicon oxide film on the silicon nitride film, a piezoelectric layer on the silicon oxide film and using Y-cut X-SAW propagation lithium tantalate, and an IDT electrode on the piezoelectric layer. A film thickness of the piezoelectric layer is equal to or less than about 1λ, Euler angles of the piezoelectric layer are (0±5°, θ, 0±5°) or (0±5°, θ, 180±5°), θ in the Euler angles of the piezoelectric layer is about 95.5°≤θ<117.5° or about −84.5°≤θ<−62.5°, and a relationship between θ in the Euler angles of the piezoelectric layer and a film thickness of the silicon nitride film is a combination shown in Table 1 or Table 2.
Claims12
An acoustic wave device comprising:
- a silicon support substrate;
- a silicon nitride film on the support substrate;
- a silicon oxide film on the silicon nitride film;
- a piezoelectric layer on the silicon oxide film and made of Y-cut X-SAW propagation lithium tantalate;
- and
- an IDT electrode directly or indirectly on the piezoelectric layer and including a plurality of electrode fingers;
- wherein
- when a wavelength defined by an electrode finger pitch of the IDT electrode is λ, a film thickness of the piezoelectric layer is equal to or less than about 1λ;
- Euler angles of the piezoelectric layer are (about 0±5°, θ, about 0±5°) or (about 0±5°, θ, about 180±5°), and θ in the Euler angles of the piezoelectric layer is about 95.5°≤θ<117.5° or about −84.5°≤θ<−62.5°;
- and
- a relationship between θ in the Euler angles of the piezoelectric layer and a film thickness of the silicon nitride film is a combination shown in Table 1 or Table 2 below:
- TABLE 1
- FILM THICKNESS OF SiN FILM
- θ
- LOWER LIMIT [λ]
- UPPER LIMIT [λ]
- 95.5 ≤ θ < 96.5
- 0.0005
- 0.746
- 96.5 ≤ θ < 97.5
- 0.0005
- 0.732
- 97.5 ≤ θ < 98.5
- 0.0005
- 0.736
- 98.5 ≤ θ < 99.5
- 0.0005
- 0.726
- 99.5 ≤ θ < 100.5
- 0.0005
- 0.724
- 100.5 ≤ θ < 101.5
- 0.0005
- 0.718
- 101.5 ≤ θ < 102.5
- 0.0005
- 0.712
- 102.5 ≤ θ < 103.5
- 0.0005
- 0.71
- 103.5 ≤ θ < 104.5
- 0.0005
- 0.704
- 104.5 ≤ θ < 105.5
- 0.0005
- 0.702
- 105.5 ≤ θ < 106.5
- 0.0005
- 0.698
- 106.5 ≤ θ < 107.5
- 0.0005
- 0.695
- 107.5 ≤ θ < 108.5
- 0.0005
- 0.695
- 108.5 ≤ θ < 109.5
- 0.0005
- 0.692
- 109.5 ≤ θ < 110.5
- 0.0005
- 0.689
- 110.5 ≤ θ < 111.5
- 0.0005
- 0.689
- 111.5 ≤ θ < 112.5
- 0.0005
- 0.69
- 112.5 ≤ θ < 113.5
- 0.0005
- 0.686
- 113.5 ≤ θ < 114.5
- 0.0005
- 0.684
- 114.5 ≤ θ < 115.5
- 0.0005
- 0.684
- 115.5 ≤ θ < 116.5
- 0.0005
- 0.682
- 116.5 ≤ θ < 117.5
- 0.0005
- 0.666;
- and
- TABLE 2
- FILM THICKNESS OF SiN FILM
- θ
- LOWER LIMIT [λ]
- UPPER LIMIT [λ]
- −84.5 ≤ θ < −83.5
- 0.0005
- 0.746
- −83.5 ≤ θ < −82.5
- 0.0005
- 0.732
- −82.5 ≤ θ < −81.5
- 0.0005
- 0.736
- −81.5 ≤ θ < −80.5
- 0.0005
- 0.726
- −80.5 ≤ θ < −79.5
- 0.0005
- 0.724
- −79.5 ≤ θ < −78.5
- 0.0005
- 0.718
- −78.5 ≤ θ < −77.5
- 0.0005
- 0.712
- −77.5 ≤ θ < −76.5
- 0.0005
- 0.71
- −76.5 ≤ θ < −75.5
- 0.0005
- 0.704
- −75.5 ≤ θ < −74.5
- 0.0005
- 0.702
- −74.5 ≤ θ < −73.5
- 0.0005
- 0.698
- −73.5 ≤ θ < −72.5
- 0.0005
- 0.695
- −72.5 ≤ θ < −71.5
- 0.0005
- 0.695
- −71.5 ≤ θ < −70.5
- 0.0005
- 0.692
- −70.5 ≤ θ < −69.5
- 0.0005
- 0.689
- −69.5 ≤ θ < −68.5
- 0.0005
- 0.689
- −68.5 ≤ θ < −67.5
- 0.0005
- 0.69
- −67.5 ≤ θ < −66.5
- 0.0005
- 0.686
- −66.5 ≤ θ < −65.5
- 0.0005
- 0.684
- −65.5 ≤ θ < −64.5
- 0.0005
- 0.684
- −64.5 ≤ θ < −63.5
- 0.0005
- 0.682
- −63.5 ≤ θ < −62.5
- 0.0005
- 0.666.
151 more elements
An acoustic wave device comprising:
- a silicon support substrate;
- a silicon nitride film on the support substrate;
- a silicon oxide film on the silicon nitride film;
- a piezoelectric layer on the silicon oxide film and using Y-cut X-SAW propagation lithium tantalate;
- and
- an IDT electrode on the piezoelectric layer and including a plurality of electrode fingers;
- wherein
- when a wavelength defined by an electrode finger pitch of the IDT electrode is λ, a film thickness of the piezoelectric layer is equal to or less than about 1λ;
- Euler angles of the piezoelectric layer are (about 0±5°, θ, about 0±5°), and θ in the Euler angles of the piezoelectric layer is about 117.5°≤θ<129.5°;
- and
- a relationship between θ in the Euler angles of the piezoelectric layer and a film thickness of the silicon nitride film is a combination shown in Table 3 below:
- TABLE 3
- FILM THICKNESS OF SiN FILM
- θ
- LOWER LIMIT [λ]
- UPPER LIMIT [λ]
- 117.5 ≤ θ < 118.5
- 0.0005
- 0.092
- 117.5 ≤ θ < 118.5
- 0.166
- 0.597
- 118.5 ≤ θ < 119.5
- 0.0005
- 0.07
- 118.5 ≤ θ < 119.5
- 0.168
- 0.554
- 119.5 ≤ θ < 120.5
- 0.005
- 0.063
- 119.5 ≤ θ < 120.5
- 0.152
- 0.522
- 120.5 ≤ θ < 121.5
- 0.004
- 0.06
- 120.5 ≤ θ < 121.5
- 0.132
- 0.492
- 121.5 ≤ θ < 122.5
- 0.022
- 0.052
- 121.5 ≤ θ < 122.5
- 0.12
- 0.466
- 122.5 ≤ θ < 123.5
- 0.22
- 0.43
- 123.5 ≤ θ < 124.5
- 0.24
- 0.4
- 124.5 ≤ θ < 125.5
- 0.25
- 0.38
- 125.5 ≤ θ < 126.5
- 0.25
- 0.38
- 126.5 ≤ θ < 127.5
- 0.25
- 0.36
- 127.5 ≤ θ < 128.5
- 0.25
- 0.31
- 128.5 ≤ θ < 129.5
- 0.25
- 0.28.
64 more elements
An acoustic wave device comprising:
- a silicon support substrate;
- a silicon nitride film on the support substrate;
- a silicon oxide film on the silicon nitride film;
- a piezoelectric layer on the silicon oxide film and using Y-cut X-SAW propagation lithium tantalate;
- and
- an IDT electrode on the piezoelectric layer and including a plurality of electrode fingers;
- wherein
- when a wavelength defined by an electrode finger pitch of the IDT electrode is λ, a film thickness of the piezoelectric layer is equal to or less than about 1λ;
- Euler angles of the piezoelectric layer are (about 0±5°, θ, about 0±5°), and θ in the Euler angles of the piezoelectric layer is about 85.5°≤θ<95.5°;
- and
- a relationship between θ in the Euler angles of the piezoelectric layer and a film thickness of the silicon nitride film is a combination shown in Table 4 below:
- TABLE 4
- FILM THICKNESS OF SiN FILM
- θ
- LOWER LIMIT [λ]
- UPPER LIMIT [λ]
- 85.5 ≤ θ < 86.5
- 0.0005
- 0.03
- 85.5 ≤ θ < 86.5
- 0.43
- 0.46
- 86.5 ≤ θ < 87.5
- 0.0005
- 0.038
- 86.5 ≤ θ < 87.5
- 0.42
- 0.47
- 87.5 ≤ θ < 88.5
- 0.0005
- 0.048
- 87.5 ≤ θ < 88.5
- 0.412
- 0.485
- 88.5 ≤ θ < 89.5
- 0.0005
- 0.058
- 88.5 ≤ θ < 89.5
- 0.404
- 0.506
- 89.5 ≤ θ < 90.5
- 0.0005
- 0.07
- 89.5 ≤ θ < 90.5
- 0.388
- 0.52
- 90.5 ≤ θ < 91.5
- 0.0005
- 0.085
- 90.5 ≤ θ < 91.5
- 0.37
- 0.538
- 91.5 ≤ θ < 92.5
- 0.0005
- 0.102
- 91.5 ≤ θ < 92.5
- 0.346
- 0.56
- 92.5 ≤ θ < 93.5
- 0.0005
- 0.128
- 92.5 ≤ θ < 93.5
- 0.315
- 0.59
- 93.5 ≤ θ < 94.5
- 0.0005
- 0.166
- 93.5 ≤ θ < 94.5
- 0.295
- 0.616
- 94.5 ≤ θ < 95.5
- 0.0005
- 0.226
- 94.5 ≤ θ < 95.5
- 0.284
- 0.66.
73 more elements
Dependencies are inferred from the claim text.