Back to results
US 7,425,788 B2Granted
Surface acoustic wave device
AssigneeMurata Manufacturing Co., Ltd.
InventorsMichio Kadota, Tetsuya Kimura
Life of this patent
Estimating the term…
Abstract
In a surface acoustic wave device, a plurality of grooves are provided on a piezoelectric substrate, an electrode film defining an IDT electrode is formed by filling an electrode material in the grooves, an insulator layer, such as a SiO2 film, is arranged so as to cover the piezoelectric substrate and the electrode film formed in the grooves, and the surface of the insulator layer is flattened.
Claims24
A surface acoustic wave device comprising:
- a LiTaO3 substrate including a plurality of grooves provided in an upper surface thereof;
- and
- an IDT electrode defined by Al disposed in the grooves provided in the upper surface of the substrate;
- and
- a SiO2 layer arranged to cover the LiTaO3 substrate and the IDT electrode;
- wherein
- the upper surface of the SiO2 layer is flattened;
- the Euler angle of the LiTaO3 substrate is within any one of the ranges provided in the Table below using λ as the wavelength of a surface acoustic wave;
- the film thickness of the IDT electrode is within the range indicated in the Table below that is associated with a corresponding range of the Euler angle of the LiTaO3 substrate;
- and the thickness of the SiO2 layer is within the range indicated in the Table below that is associated with a corresponding range of the film thickness of the IDT electrode:
- α = 0.05 or less
- θ of Euler angle (0, θ, 0)
- 0.125 <= SiO2 layer thickness <= 0.20
- 0.02 <= Al thickness < 0.04
- (0, 114° to 142°, 0)
- 0.04 <= Al thickness < 0.06
- (0, 115° to 143°, 0)
- 0.06 <= Al thickness < 0.1
- (0, 113° to 145°, 0)
- 0.1 <= Al thickness < 0.14
- (0, 112° to 146°, 0)
- 0.20 <= SiO2 layer thickness <= 0.275
- 0.02 <= Al thickness < 0.04
- (0, 113° to 140°, 0)
- 0.04 <= Al thickness < 0.06
- (0, 113° to 140°, 0)
- 0.06 <= Al thickness < 0.1
- (0, 111° to 140°, 0)
- 0.1 <= Al thickness < 0.14
- (0, 111° to 140°, 0)
- 0.275 <= SiO2 layer thickness <= 0.35
- 0.02 <= Al thickness < 0.04
- (0, 111° to 137°, 0)
- 0.04 <= Al thickness < 0.06
- (0, 111° to 137°, 0)
- 0.06 <= Al thickness < 0.1
- (0, 109° to 136°, 0)
- 0.1 <= Al thickness < 0.14
- (0, 107° to 136°, 0)
- wherein, SiO2 layer thickness and Al thickness are each normalized film thickness H/λ.
37 more elements
A surface acoustic wave device comprising:
- a LiTaO3 substrate including a plurality of grooves provided in an upper surface thereof;
- and
- an IDT electrode defined by Al disposed in the grooves provided in the upper surface of the substrate;
- and
- a SiO2 layer arranged to cover the LiTaO3 substrate and the IDT electrode;
- wherein
- the upper surface of the SiO2 layer is flattened;
- the Euler angle of the LiTaO3 substrate is within any one of the ranges provided in the Table shown below using λ as the wave length of a surface acoustic wave;
- the film thickness of the IDT electrode is within the range indicated in the Table below that is associated with a corresponding range of the Euler angle of the LiTaO3 substrate;
- and
- the thickness of the SiO2 layer is within the range indicated in the Table below that is associated with a corresponding range of the film thickness of the IDT electrode:
- α = 0.05 or less
- θ of Euler angle (0, θ, 0)
- 0.125 <= SiO2 layer thickness <= 0.20
- 0.02 <= Al thickness < 0.04
- (0, 119° to 152°, 0)
- 0.04 <= Al thickness < 0.06
- (0, 120° to 153°, 0)
- 0.06 <= Al thickness < 0.1
- (0, 124° to 158°, 0)
- 0.1 <= Al thickness < 0.14
- (0, 128° to 155°, 0)
- 0.20 <= SiO2 layer thickness <= 0.275
- 0.02 <= Al thickness < 0.04
- (0, 123° to 152°, 0)
- 0.04 <= Al thickness < 0.06
- (0, 124.5° to 153°, 0)
- 0.06 <= Al thickness < 0.1
- (0, 123.5° to 154°, 0)
- 0.1 <= Al thickness < 0.14
- (0, 119° to 157°, 0)
- 0.275 <= SiO2 layer thickness <= 0.35
- 0.02 <= Al thickness < 0.04
- (0, 124° to 150°, 0)
- 0.04 <= Al thickness < 0.06
- (0, 124° to 146°, 0)
- 0.06 <= Al thickness < 0.1
- (0, 114° to 149°, 0)
- 0.1 <= Al thickness < 0.14
- (0, 103° to 148°, 0)
- wherein, the SiO2 layer thickness and Al thickness are each normalized film thickness H/λ.
38 more elements
A surface acoustic wave device comprising:
- a LiNbO3 substrate including a plurality of grooves provided in an upper surface thereof;
- and
- an IDT electrode which is defined by Al disposed in the grooves provided in the upper surface of the substrate;
- and
- a SiO2 layer arranged to cover the LiNbO3 substrate and the IDT electrode;
- wherein
- the upper surface of the SiO2 layer is flattened;
- λ is used for denoting the wavelength of a surface acoustic wave;
- a normalized film thickness of the IDT electrode is within the range of about 0.04 to about 0.16;
- a normalized film thickness of the SiO2 layer is within the range of 0.2 to 0.4;
- and
- the Euler angle of the LiNbO3 substrate is within any one of the ranges provided in the Table shown below:
- θ of Euler angle (0°, θ, 0°)
- (0°, 85° to 120°, 0°)
- (0°, 125° to 141°, 0°)
- (0°, 145° to 164°, 0°)
- (0°, 160° to 180°, 0°).
14 more elements
Dependencies are inferred from the claim text.