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US 7,888,841 B2Granted
Boundary acoustic wave device
AssigneeMurata Manufacturing Co., Ltd.
InventorsMichio Kadota, Tetsuya Kimura
Life of this patent
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Abstract
A boundary acoustic wave device includes a LiNbO3 substrate having a plurality of grooves provided in the upper surface thereof, electrode layers which are defined by a metal material filled in the grooves and which include IDT electrodes, and a dielectric layer, such as a SiO2 layer, provided over the upper surface of the piezoelectric substrate and the electrodes. The upper surface of the dielectric layer is flat or substantially flat. The thickness of the electrodes, θ of the Euler angles (0°, θ, −45° to +45°) of the LiNbO3 substrate, and the thickness of the dielectric layer are within any of the ranges shown in Table 1.
Claims6
A boundary acoustic wave device comprising:
- a LiNbO3 substrate including a plurality of grooves provided in an upper surface thereof and having Euler angles (0° , θ, −45° to +45°);
- electrodes defined by metal material filled in the grooves;
- and
- a silicon dioxide layer arranged over the LiNbO3 substrate and the electrodes;
- wherein
- the upper surface of the silicon dioxide layer is flat or substantially flat;
- the metal material defining the electrodes is at least one selected from the group consisting of Al, Ti, Ni, Cr, Cu, W, Ta, Pt, and Ag;
- Al and Ti are grouped into a first group;
- Ni and Cr are grouped into a second group;
- Cu, W, Ta, Pt, and Ag are grouped into a third group;
- and
- a thickness of the electrodes made of the metal materials assigned to each group, θ of the Euler angles of the LiNbO3 substrate, and the thickness of the silicon dioxide layer are within any of the ranges shown in the table below:
- α ≦ 0.1
- θ of Euler
- angles (0°, θ,
- −45° to 45°)
- 0.04 ≦ Thickness of first
- (0, 76 to 106,
- 0.8 ≦ Thickness of silicon
- group electrode < 0.07
- −45 to 45)
- dioxide layer ≦ 2.5
- 0.07 ≦ Thickness of first
- (0, 66 to 116,
- 0.8 ≦ Thickness of silicon
- group electrode < 0.1
- −45 to 45)
- dioxide layer ≦ 2.5
- 0.1 ≦ Thickness of first
- (0, 56 to 125,
- 0.8 ≦ Thickness of silicon
- group electrode ≦ 0.2
- −45 to 45)
- dioxide layer ≦ 2.5
- 0.01 ≦ Thickness of second
- (0, 71 to 101,
- 0.8 ≦ Thickness of silicon
- group electrode < 0.02
- −45 to 45)
- dioxide layer ≦ 3.0
- 0.02 ≦ Thickness of second
- (0, 68 to 103,
- 0.8 ≦ Thickness of silicon
- group electrode < 0.06
- −45 to 45)
- dioxide layer ≦ 3.0
- 0.06 ≦ Thickness of second
- (0, 66 to 109,
- 0.8 ≦ Thickness of silicon
- group electrode < 0.08
- −45 to 45)
- dioxide layer ≦ 3.0
- 0.08 ≦ Thickness of second
- (0, 61 to 123,
- 0.8 ≦ Thickness of silicon
- group electrode ≦ 0.16
- −45 to 45)
- dioxide layer ≦ 3.0
- 0.01 ≦ Thickness of third
- (0, 61 to 112,
- 0.8 ≦ Thickness of silicon
- group electrode < 0.02
- −45 to 45)
- dioxide layer ≦ 4.0
- 0.02 ≦ Thickness of third
- (0, 60 to 122,
- 0.8 ≦ Thickness of silicon
- group electrode < 0.06
- −45 to 45)
- dioxide layer ≦ 4.0
- 0.06 ≦ Thickness of third
- (0, 56 to 132,
- 0.8 ≦ Thickness of silicon
- group electrode < 0.08
- −45 to 45)
- dioxide layer ≦ 4.0
- 0.08 ≦ Thickness of third
- (0, 51 to 136,
- 0.8 ≦ Thickness of silicon
- group electrode ≦ 0.10
- −45 to 45)
- dioxide layer ≦ 4.0
- The thickness of each electrode and the thickness of the silicon dioxide layer are normalized thickness H/λ (λ is the wavelength of a boundary acoustic wave).
80 more elements
A boundary acoustic wave device comprising:
- a LiTaO3 substrate including a plurality of grooves provided in an upper surface thereof and having Euler angles (0° , θ, −45° to +45°);
- electrodes defined by a metal material filled in the grooves;
- and
- a silicon dioxide layer arranged over the LiTaO3 substrate and the electrodes;
- wherein
- the upper surface of the silicon dioxide layer is flat or substantially flat;
- the metal material used to define the electrodes is at least one selected from the group consisting of Al, Cu, Au, Ta, and Pt;
- and
- the thickness of the electrodes, θ of the Euler angles of the LiTaO3 substrate, and the thickness of the silicon dioxide layer are within any of the ranges shown in the table below:
- α = 0
- θ of Euler angles (0°, θ, −45° to 45°)
- 0.04 ≦ Thickness of Al electrode < 0.08
- (0, 124 to 128, −45 to 45)
- 0.8 ≦ Thickness of silicon dioxide layer ≦ 2.5
- 0.08 ≦ Thickness of Al electrode < 0.1
- (0, 124 to 128, −45 to 45)
- 0.8 ≦ Thickness of silicon dioxide layer ≦ 2.5
- 0.1 ≦ Thickness of Al electrode ≦ 0.25
- (0, 124 to 128, −45 to 45)
- 0.8 ≦ Thickness of silicon dioxide layer ≦ 2.5
- 0.02 ≦ Thickness of Cu electrode < 0.04
- (0, 127 to 129, −45 to 45)
- 0.8 ≦ Thickness of silicon dioxide layer ≦ 2.5
- 0.04 ≦ Thickness of Cu electrode < 0.08
- (0, 127 to 131, −45 to 45)
- 0.8 ≦ Thickness of silicon dioxide layer ≦ 2.5
- 0.08 ≦ Thickness of Cu electrode ≦ 0.1
- (0, 127 to 135, −45 to 45)
- 0.8 ≦ Thickness of silicon dioxide layer ≦ 2.5
- 0.02 ≦ Thickness of Au electrode < 0.03
- (0, 135 to 136, −45 to 45)
- 0.8 ≦ Thickness of silicon dioxide layer ≦ 2.5
- 0.03 ≦ Thickness of Au electrode < 0.06
- (0, 135 to 139, −45 to 45)
- 0.8 ≦ Thickness of silicon dioxide layer ≦ 2.5
- 0.06 ≦ Thickness of Au electrode ≦ 0.1
- (0, 135 to 140, −45 to 45)
- 0.8 ≦ Thickness of silicon dioxide layer ≦ 2.5
- 0.03 ≦ Thickness of Ta electrode < 0.06
- (0, 129 to 134, −45 to 45)
- 0.8 ≦ Thickness of silicon dioxide layer ≦ 2.5
- 0.06 ≦ Thickness of Ta electrode < 0.08
- (0, 129 to 134, −45 to 45)
- 0.8 ≦ Thickness of silicon dioxide layer ≦ 2.5
- 0.08 ≦ Thickness of Ta electrode ≦ 0.1
- (0, 129 to 136, −45 to 45)
- 0.8 ≦ Thickness of silicon dioxide layer ≦ 2.5
- 0.02 ≦ Thickness of Pt electrode < 0.04
- (0, 130 to 131, −45 to 45)
- 0.8 ≦ Thickness of silicon dioxide layer ≦ 2.5
- 0.04 ≦ Thickness of Pt electrode < 0.08
- (0, 133 to 135, −45 to 45)
- 0.8 ≦ Thickness of silicon dioxide layer ≦ 2.5
- 0.08 ≦ Thickness of Pt electrode ≦ 0.1
- (0, 133 to 138, −45 to 45)
- 0.8 ≦ Thickness of silicon dioxide layer ≦ 2.5
- The thickness of each electrode and the thickness of the silicon dioxide layer are normalized thickness H/λ (λ is the wavelength of a boundary acoustic wave).
54 more elements
Dependencies are inferred from the claim text.