WO2015137090A1 - 弾性波装置 - Google Patents
弾性波装置 Download PDFInfo
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- WO2015137090A1 WO2015137090A1 PCT/JP2015/054769 JP2015054769W WO2015137090A1 WO 2015137090 A1 WO2015137090 A1 WO 2015137090A1 JP 2015054769 W JP2015054769 W JP 2015054769W WO 2015137090 A1 WO2015137090 A1 WO 2015137090A1
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/46—Filters
- H03H9/64—Filters using surface acoustic waves
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/02—Details
- H03H9/02535—Details of surface acoustic wave devices
- H03H9/02543—Characteristics of substrate, e.g. cutting angles
- H03H9/02559—Characteristics of substrate, e.g. cutting angles of lithium niobate or lithium-tantalate substrates
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/02—Details
- H03H9/125—Driving means, e.g. electrodes, coils
- H03H9/145—Driving means, e.g. electrodes, coils for networks using surface acoustic waves
- H03H9/14544—Transducers of particular shape or position
Definitions
- the present invention relates to an elastic wave device in which an IDT electrode and a high acoustic velocity film are laminated on a LiNbO 3 substrate, and more particularly to an elastic wave device using a leaky elastic wave.
- Patent Document 1 discloses a surface acoustic wave filter using a 64 ° ⁇ 3 ° Y-cut X-propagation LiNbO 3 substrate or a 41 ° ⁇ 3 ° Y-cut X-propagation LiNbO 3 .
- an IDT electrode is formed on a piezoelectric substrate made of LiNbO 3 .
- a protective film made of SiO 2 , SiNx, Si or Al 2 O 3 is formed on the surface acoustic wave propagation portion of the LiNbO 3 substrate.
- a reflector electrode has a bus-bar electrode extended in the surface acoustic wave propagation
- the bus bar electrode has a width equal to or less than half the wavelength of the surface acoustic wave.
- leaky elastic waves and love waves are known as elastic waves propagating through LiNbO 3 .
- the leaky elastic wave has a high sound speed, but has a large attenuation constant, and it is difficult to reduce the loss.
- love waves are low in sound speed and difficult to increase in sound speed, but are difficult to leak. Therefore, conventionally, attempts have been made to increase the sound speed by using a leaky elastic wave and laminating a high sound speed film.
- the structure in which the high sound velocity films are laminated has a problem that the acoustic velocity increases, so that leaky elastic waves are output and the damping constant increases.
- An object of the present invention is to provide a high acoustic velocity and low loss elastic wave device using a leaky elastic wave having a small attenuation constant.
- Acoustic wave device includes a LiNbO 3 substrate, and the IDT electrode provided on the LiNbO 3 substrate, the LiNbO 3 aluminum nitride film provided on the substrate so as to cover the IDT electrode The leakage elastic wave propagating through the LiNbO 3 substrate is used.
- the IDT electrode is made of a metal mainly composed of one material selected from the group consisting of Cu, Al, Au, Pt and Ni, and the Euler angle of the LiNbO 3 substrate is set. (0 ° ⁇ 5 °, ⁇ , 0 ° ⁇ 5 °), where the wavelength normalized thickness of the IDT electrode is X and the Euler angle ⁇ is Y, the metal constituting the IDT electrode Depending on the type and the range of the wavelength normalized thickness of the aluminum nitride film, the Euler angle Y, which is ⁇ , is set to one of the ranges shown in Tables 1 to 5 below.
- Acoustic wave device includes a LiNbO 3 substrate, and the IDT electrode provided on the LiNbO 3 substrate, the LiNbO 3 silicon nitride provided on the substrate film so as to cover the IDT electrode The leakage elastic wave propagating through the LiNbO 3 substrate is used.
- the IDT electrode is made of a metal mainly composed of one material selected from the group consisting of Cu, Al, Au, Pt and Ni, and the Euler angle of the LiNbO 3 substrate is set to (0 ° ⁇ 5 °, ⁇ , 0 ° ⁇ 5 °), the wavelength normalized thickness of the IDT electrode is X, and the Euler angle ⁇ is Y, and the type of metal constituting the IDT electrode, and Depending on the wavelength normalized thickness range of the silicon nitride film, the Euler angle ⁇ , Y, is set to one of the ranges shown in Tables 6 to 10 below.
- an IDT electrode is provided on a LiNbO 3 substrate, and an aluminum nitride film or a silicon nitride film covers the IDT electrode. Is provided. Therefore, it is possible to increase the speed of the surface acoustic wave device using leaky elastic waves.
- Y which is Euler angle ⁇ , is set to a specific range. The constant can be reduced. Therefore, it is possible to achieve high sound speed and low loss.
- FIG. 1 is a schematic front sectional view of an acoustic wave device according to a first embodiment of the present invention.
- FIG. 2 is a diagram showing the relationship between the acoustic velocity of leaky elastic waves and Rayleigh waves propagating through LiNbO 3 and Euler angle ⁇ .
- FIG. 3 is a diagram showing the relationship between the Euler angle ⁇ of LiNbO 3 and the attenuation constant of the sound velocity Vf in the open state and the attenuation constant ⁇ of the sound velocity Vm in the short-circuit state.
- FIG. 4 shows the sound speed at the resonance frequency fr and the sound speed at the antiresonance frequency fa and the wavelength of Cu in a structure in which an IDT electrode made of Cu is formed on a LiNbO 3 substrate with Euler angles (0 °, 94 °, 0 °). It is a figure which shows the relationship with normalized thickness.
- FIG. 5 shows a structure in which an IDT electrode made of a Cu film having a wavelength normalized thickness of 0.2 is formed on a LiNbO 3 substrate with Euler angles (0 °, 131 °, 0 °), and an AlN film is laminated.
- FIG. 5 is a diagram showing the relationship between the wavelength normalized thickness of an AlN film and the sound velocity.
- FIG. 6 shows a wavelength normalized thickness of an AlN film in a structure in which an IDT electrode made of Cu having a wavelength normalized thickness of 0.08 is formed on a LiNbO 3 substrate and an AlN film of various thicknesses is laminated. It is a figure which shows the relationship between (theta) of Euler angles and attenuation constant (alpha).
- FIG. 7 shows a wavelength normalized thickness of an AlN film in a structure in which an IDT electrode made of Au having a wavelength normalized thickness of 0.038 is formed on a LiNbO 3 substrate, and an AlN film of various thicknesses is laminated. It is a figure which shows the relationship between (theta) of Euler angles and attenuation constant (alpha).
- FIG. 7 shows a wavelength normalized thickness of an AlN film in a structure in which an IDT electrode made of Au having a wavelength normalized thickness of 0.038 is formed on a LiNbO 3 substrate, and an AlN film of various thicknesses is laminated
- FIG. 8 shows a wavelength normalized thickness of an AlN film in a structure in which an IDT electrode made of Pt having a wavelength normalized thickness of 0.034 is formed on a LiNbO 3 substrate and an AlN film having various thicknesses is laminated. It is a figure which shows the relationship between (theta) of Euler angles and attenuation constant (alpha).
- FIG. 9 shows a wavelength normalized thickness of an AlN film in a structure in which an IDT electrode made of Ni having a wavelength normalized thickness of 0.08 is formed on a LiNbO 3 substrate, and an AlN film of various thicknesses is laminated. It is a figure which shows the relationship between (theta) of Euler angles and attenuation constant (alpha).
- FIG. 9 shows a wavelength normalized thickness of an AlN film in a structure in which an IDT electrode made of Ni having a wavelength normalized thickness of 0.08 is formed on a LiNbO 3 substrate, and an AlN film of various thicknesses is laminated
- FIG. 10 shows a wavelength normalized thickness of an AlN film in a structure in which an IDT electrode made of Al having a wavelength normalized thickness of 0.264 is formed on a LiNbO 3 substrate, and an AlN film having various thicknesses is laminated. It is a figure which shows the relationship between (theta) of Euler angles and attenuation constant (alpha).
- FIG. 11 shows the Euler angle of LiNbO 3 in which the attenuation constant ⁇ can be 0.02 or less when the IDT electrode is made of Cu and the wavelength normalized thickness of the AlN film is 0.02 or more and less than 0.075. It is a figure showing the line which shows the minimum of Y which is (theta) of, and the line which shows an upper limit.
- FIG. 12 shows the Euler angle of LiNbO 3 in which the attenuation constant ⁇ can be 0.02 or less when the IDT electrode is made of Cu and the wavelength normalized thickness of the AlN film is 0.075 or more and less than 0.125. It is a figure showing the line which shows the minimum of Y which is (theta) of, and the line which shows an upper limit.
- FIG. 13 shows the Euler angle of LiNbO 3 that can make the attenuation constant ⁇ 0.02 or less when the IDT electrode is made of Cu and the wavelength normalized thickness of the AlN film is 0.125 or more and less than 0.175. It is a figure showing the line which shows the minimum of Y which is (theta), and the line which shows an upper limit.
- FIG. 13 shows the Euler angle of LiNbO 3 that can make the attenuation constant ⁇ 0.02 or less when the IDT electrode is made of Cu and the wavelength normalized thickness of the AlN film is 0.125 or more and less than 0.175. It is
- FIG. 14 shows the Euler angle of LiNbO 3 that allows the attenuation constant ⁇ to be 0.02 or less when the IDT electrode is made of Cu and the wavelength normalized thickness of the AlN film is 0.175 or more and less than 0.225. It is a figure showing the line which shows the minimum of Y which is (theta), and the line which shows an upper limit.
- FIG. 15 shows the Euler angle of LiNbO 3 that allows the weight loss constant ⁇ to be 0.02 or less when the IDT electrode is made of Cu and the wavelength normalized thickness of the AlN film is 0.225 or more and less than 0.275. It is a figure showing the line which shows the minimum of Y which is (theta), and the line which shows an upper limit.
- FIG. 15 shows the Euler angle of LiNbO 3 that allows the attenuation constant ⁇ to be 0.02 or less when the IDT electrode is made of Cu and the wavelength normalized thickness of the AlN film is 0.175 or more and less than 0.225. It is a figure
- FIG. 16 shows the center value of the range of Y corresponding to Euler angle ⁇ that can set attenuation constant ⁇ to 0.02 or less depending on each wavelength normalized thickness range of the AlN film when the IDT electrode is made of Al. It is a figure showing each line.
- FIG. 17 shows the Euler angle of LiNbO 3 that can make the attenuation constant ⁇ 0.02 or less when the IDT electrode is made of Au and the wavelength normalized thickness of the AlN film is 0.02 or more and less than 0.075. It is a figure showing the line which shows the minimum of Y which is (theta), and the line which shows an upper limit.
- FIG. 17 shows the Euler angle of LiNbO 3 that can make the attenuation constant ⁇ 0.02 or less when the IDT electrode is made of Au and the wavelength normalized thickness of the AlN film is 0.02 or more and less than 0.075. It is a figure showing the line which shows the minimum of Y which is (theta), and the line which shows an upper
- FIG. 18 shows the Euler angle ⁇ of LiNbO 3 that can have an attenuation constant ⁇ of 0.02 or less when the IDT electrode is made of Au and the wavelength normalized thickness of the AlN film is 0.075 or more and less than 0.125. It is a figure showing the line which shows the minimum of Y which is and the line which shows an upper limit.
- FIG. 19 shows the Euler angle ⁇ of LiNbO 3 that allows the attenuation constant ⁇ to be 0.02 or less when the IDT electrode is made of Au and the wavelength normalized thickness of the AlN film is 0.125 or more and less than 0.175. It is a figure showing the line which shows the minimum of Y which is and the line which shows an upper limit.
- FIG. 19 shows the Euler angle ⁇ of LiNbO 3 that allows the attenuation constant ⁇ to be 0.02 or less when the IDT electrode is made of Au and the wavelength normalized thickness of the AlN film is 0.125 or more and less than 0.175. It is a figure showing
- FIG. 20 shows the Euler angle ⁇ of LiNbO 3 that allows the attenuation constant ⁇ to be 0.02 or less when the IDT electrode is made of Au and the wavelength normalized thickness of the AlN film is 0.175 or more and less than 0.225. It is a figure showing the line which shows the minimum of Y which is and the line which shows an upper limit.
- FIG. 21 shows the Euler angle ⁇ of LiNbO 3 that can make the attenuation constant ⁇ 0.02 or less when the IDT electrode is made of Au and the wavelength normalized thickness of the AlN film is 0.225 or more and less than 0.275. It is a figure showing the line which shows the minimum of Y which is and the line which shows an upper limit.
- FIG. 21 shows the Euler angle ⁇ of LiNbO 3 that allows the attenuation constant ⁇ to be 0.02 or less when the IDT electrode is made of Au and the wavelength normalized thickness of the AlN film is 0.175 or more and less than 0.225. It is a figure showing the line
- FIG. 22 shows the Euler angle ⁇ of LiNbO 3 that can have an attenuation constant ⁇ of 0.02 or less when the IDT electrode is made of Pt and the wavelength normalized thickness of the AlN film is 0.02 or more and less than 0.075. It is a figure showing the line which shows the minimum of Y which is and the line which shows an upper limit.
- FIG. 23 shows the Euler angle ⁇ of LiNbO 3 that allows the attenuation constant ⁇ to be 0.02 or less when the IDT electrode is made of Pt and the wavelength normalized thickness of the AlN film is 0.075 or more and less than 0.125. It is a figure showing the line which shows the minimum of Y which is and the line which shows an upper limit.
- FIG. 24 shows the Euler angle ⁇ of LiNbO 3 that allows the attenuation constant ⁇ to be 0.02 or less when the IDT electrode is made of Pt and the wavelength normalized thickness of the AlN film is 0.125 or more and less than 0.175. It is a figure showing the line which shows the minimum of Y which is and the line which shows an upper limit.
- FIG. 25 shows the Euler angle ⁇ of LiNbO 3 that can have an attenuation constant ⁇ of 0.02 or less when the IDT electrode is made of Pt and the wavelength normalized thickness of the AlN film is 0.175 or more and less than 0.225. It is a figure showing the line which shows the minimum of Y which is and the line which shows an upper limit.
- FIG. 25 shows the Euler angle ⁇ of LiNbO 3 that allows the attenuation constant ⁇ to be 0.02 or less when the IDT electrode is made of Pt and the wavelength normalized thickness of the AlN film is 0.125 or more and less than 0.175. It is
- FIG. 26 shows the Euler angle ⁇ of LiNbO 3 that can make the attenuation constant ⁇ 0.02 or less when the IDT electrode is made of Pt and the wavelength normalized thickness of the AlN film is 0.225 or more and less than 0.275. It is a figure showing the line which shows the minimum of Y which is and the line which shows an upper limit.
- FIG. 27 shows the Euler angle ⁇ of LiNbO 3 that can have an attenuation constant ⁇ of 0.02 or less when the IDT electrode is made of Ni and the wavelength normalized thickness of the AlN film is 0.02 or more and less than 0.075. It is a figure showing the line which shows the minimum of Y which is and the line which shows an upper limit.
- FIG. 28 shows the Euler angle ⁇ of LiNbO 3 that can make the attenuation constant ⁇ 0.02 or less when the IDT electrode is made of Ni and the wavelength normalized thickness of the AlN film is 0.075 or more and less than 0.125. It is a figure showing the line which shows the minimum of Y which is and the line which shows an upper limit.
- FIG. 29 shows the Euler angle of LiNbO 3 that can make the attenuation constant ⁇ 0.02 or less when the IDT electrode is made of Ni and the wavelength normalized thickness of the AlN film is 0.125 or more and less than 0.175. It is a figure showing the line which shows the minimum of Y which is (theta), and the line which shows an upper limit.
- FIG. 29 shows the Euler angle of LiNbO 3 that can make the attenuation constant ⁇ 0.02 or less when the IDT electrode is made of Ni and the wavelength normalized thickness of the AlN film is 0.125 or more and less than 0.175. It is a figure showing the line
- FIG. 30 shows the Euler angle ⁇ of LiNbO 3 that can have an attenuation constant ⁇ of 0.02 or less when the IDT electrode is made of Ni and the wavelength normalized thickness of the AlN film is 0.175 or more and less than 0.225. It is a figure showing the line which shows the minimum of Y which is and the line which shows an upper limit.
- FIG. 31 shows the Euler angle ⁇ of LiNbO 3 that allows the attenuation constant ⁇ to be 0.02 or less when the IDT electrode is made of Ni and the wavelength normalized thickness of the AlN film is 0.225 or more and less than 0.275. It is a figure showing the line which shows the minimum of Y which is and the line which shows an upper limit.
- FIG. 32 shows an Si 3 electrode formed on a LiNbO 3 substrate having Euler angles (0 °, 160 °, 0 °) with a wavelength normalized thickness of 0.22 in the second embodiment.
- an IDT electrode made of Cu having a wavelength normalized thickness of 0.08 is formed on a LiNbO 3 substrate with Euler angles (0 °, ⁇ , 0 °), and Si 3 N 4 films having various thicknesses are formed.
- FIG. 6 is a diagram illustrating a relationship between Euler angle ⁇ and attenuation constant ⁇ in a structure in which layers are stacked.
- FIG. 34 an IDT electrode made of Au having a wavelength normalized thickness of 0.038 is formed on a LiNbO 3 substrate having Euler angles (0 °, ⁇ , 0 °), and Si 3 N 4 films having various thicknesses are formed.
- FIG. 6 is a diagram illustrating a relationship between Euler angle ⁇ and attenuation constant ⁇ in a structure in which layers are stacked.
- an IDT electrode made of Pt having a wavelength normalized thickness of 0.034 is formed on an Euler angle (0 °, ⁇ , 0 °) LiNbO 3 substrate, and Si 3 N 4 films having various thicknesses are formed.
- FIG. 35 an IDT electrode made of Pt having a wavelength normalized thickness of 0.034 is formed on an Euler angle (0 °, ⁇ , 0 °) LiNbO 3 substrate, and Si 3 N 4 films having various thicknesses are formed.
- FIG. 6 is a diagram illustrating a relationship between Euler angle ⁇ and attenuation constant ⁇ in a structure in which layers are stacked.
- an IDT electrode made of Ni having a wavelength normalized thickness of 0.08 is formed on an Euler angle (0 °, ⁇ , 0 °) LiNbO 3 substrate, and Si 3 N 4 films having various thicknesses are formed.
- FIG. 6 is a diagram illustrating a relationship between Euler angle ⁇ and attenuation constant ⁇ in a structure in which layers are stacked.
- FIG. 36 an IDT electrode made of Ni having a wavelength normalized thickness of 0.08 is formed on an Euler angle (0 °, ⁇ , 0 °) LiNbO 3 substrate, and Si 3 N 4 films having various thicknesses are formed.
- FIG. 6 is a diagram illustrating a relationship between Euler angle ⁇ and attenuation constant ⁇ in a structure in which layers are stacked.
- FIG. 6 is a diagram illustrating a relationship between Euler angle ⁇ and attenuation constant ⁇ in a structure in which layers are stacked.
- FIG. 38 shows that, in the second embodiment, when the IDT electrode is made of Cu and the wavelength normalized thickness of the Si 3 N 4 film is 0.02 or more and less than 0.075, the attenuation constant ⁇ is set to 0.
- FIG. 39 shows that, in the second embodiment, when the IDT electrode is made of Cu and the wavelength normalized thickness of the Si 3 N 4 film is 0.075 or more and less than 0.125, the attenuation constant ⁇ is set to 0. It is a figure showing the line which shows the minimum of Y which is the Euler angle (theta) which can be set to 02 or less, and the line which shows an upper limit.
- FIG. 40 shows that, in the second embodiment, when the IDT electrode is made of Cu and the wavelength normalized thickness of the Si 3 N 4 film is 0.125 or more and less than 0.175, the attenuation constant ⁇ is set to 0. It is a figure showing the line which shows the minimum of Y which is the Euler angle (theta) which can be set to 02 or less, and the line which shows an upper limit.
- FIG. 41 shows that, in the second embodiment, when the IDT electrode is made of Cu and the wavelength normalized thickness of the Si 3 N 4 film is 0.175 or more and less than 0.225, the attenuation constant ⁇ is set to 0.
- FIG. 42 shows that, in the second embodiment, when the IDT electrode is made of Cu and the wavelength normalized thickness of the Si 3 N 4 film is 0.225 or more and less than 0.275, the attenuation constant ⁇ is set to 0. It is a figure showing the line which shows the minimum of Y which is the Euler angle (theta) which can be set to 02 or less, and the line which shows an upper limit.
- FIG. 43 shows that, in the second embodiment, when the IDT electrode is made of Al, and the wavelength normalized thickness of the Si 3 N 4 film is 0.02 or more and less than 0.075, the attenuation constant ⁇ is set to 0.00. It is a figure showing the line which shows the minimum of Y which is the Euler angle (theta) which can be set to 02 or less, and the line which shows an upper limit.
- FIG. 44 shows that, in the second embodiment, when the IDT electrode is made of Al and the wavelength standardized thickness of the Si 3 N 4 film is 0.075 or more and less than 0.125, the attenuation constant ⁇ is set to 0.
- FIG. 45 shows that, in the second embodiment, when the IDT electrode is made of Al, and the wavelength normalized thickness of the Si 3 N 4 film is 0.125 or more and less than 0.175, the attenuation constant ⁇ is set to 0.1. It is a figure showing the line which shows the minimum of Y which is the Euler angle (theta) which can be set to 02 or less, and the line which shows an upper limit.
- FIG. 46 shows that, in the second embodiment, when the IDT electrode is made of Al and the wavelength normalized thickness of the Si 3 N 4 film is 0.175 or more and less than 0.225, the attenuation constant ⁇ is set to 0. It is a figure showing the line which shows the minimum of Y which is the Euler angle (theta) which can be set to 02 or less, and the line which shows an upper limit.
- FIG. 47 shows that, in the second embodiment, when the IDT electrode is made of Al and the wavelength normalized thickness of the Si 3 N 4 film is 0.225 or more and less than 0.275, the attenuation constant ⁇ is set to 0.
- FIG. 48 shows that, in the second embodiment, when the IDT electrode is made of Au and the wavelength normalized thickness of the Si 3 N 4 film is 0.02 or more and less than 0.075, the attenuation constant ⁇ is set to 0. It is a figure showing the line which shows the minimum of Y which is the Euler angle (theta) which can be set to 02 or less, and the line which shows an upper limit.
- FIG. 50 shows that, in the second embodiment, when the IDT electrode is made of Au, and the wavelength normalized thickness of the Si 3 N 4 film is 0.075 or more and less than 0.125, the attenuation constant ⁇ is set to 0.00. It is a figure showing the line which shows the minimum of Y which is the Euler angle (theta) which can be set to 02 or less, and the line which shows an upper limit.
- FIG. 50 shows that, in the second embodiment, when the IDT electrode is made of Au, and the wavelength normalized thickness of the Si 3 N 4 film is 0.125 or more and less than 0.175, the attenuation constant ⁇ is set to 0.
- FIG. 51 shows that, in the second embodiment, when the IDT electrode is made of Au and the wavelength normalized thickness of the Si 3 N 4 film is 0.175 or more and less than 0.225, the attenuation constant ⁇ is set to 0. It is a figure showing the line which shows the minimum of Y which is the Euler angle (theta) which can be set to 02 or less, and the line which shows an upper limit.
- FIG. 52 shows that, in the second embodiment, when the IDT electrode is made of Au, and the wavelength normalized thickness of the Si 3 N 4 film is 0.225 or more and less than 0.275, the attenuation constant ⁇ is set to 0. It is a figure showing the line which shows the minimum of Y which is the Euler angle (theta) which can be set to 02 or less, and the line which shows an upper limit.
- FIG. 53 shows that, in the second embodiment, when the IDT electrode is made of Pt and the wavelength normalized thickness of the Si 3 N 4 film is 0.02 or more and less than 0.075, the attenuation constant ⁇ is set to 0.
- FIG. 54 shows that, in the second embodiment, when the IDT electrode is made of Pt, and the wavelength normalized thickness of the Si 3 N 4 film is 0.075 or more and less than 0.125, the attenuation constant ⁇ is set to 0. It is a figure showing the line which shows the minimum of Y which is the Euler angle (theta) which can be set to 02 or less, and the line which shows an upper limit.
- FIG. 55 shows that, in the second embodiment, when the IDT electrode is made of Pt, and the wavelength normalized thickness of the Si 3 N 4 film is 0.125 or more and less than 0.175, the attenuation constant ⁇ is set to 0. It is a figure showing the line which shows the minimum of Y which is the Euler angle (theta) which can be set to 02 or less, and the line which shows an upper limit.
- FIG. 56 shows that, in the second embodiment, when the IDT electrode is made of Pt, and the wavelength normalized thickness of the Si 3 N 4 film is 0.175 or more and less than 0.225, the attenuation constant ⁇ is set to 0.
- FIG. 57 shows that, in the second embodiment, when the IDT electrode is made of Pt and the wavelength normalized thickness of the Si 3 N 4 film is 0.225 or more and less than 0.275, the attenuation constant ⁇ is set to 0. It is a figure showing the line which shows the minimum of Y which is the Euler angle (theta) which can be set to 02 or less, and the line which shows an upper limit.
- the attenuation constant ⁇ is set to 0.00. It is a figure showing the line which shows the minimum of Y which is the Euler angle (theta) which can be set to 02 or less, and the line which shows an upper limit.
- FIG. 59 shows that, in the second embodiment, when the IDT electrode is made of Ni, and the wavelength normalized thickness of the Si 3 N 4 film is 0.075 or more and less than 0.125, the attenuation constant ⁇ is set to 0.00.
- FIG. 60 shows an attenuation constant ⁇ of 0.1 when the IDT electrode is made of Ni and the wavelength normalized thickness of the Si 3 N 4 film is 0.125 or more and less than 0.175 in the second embodiment. It is a figure showing the line which shows the minimum of Y which is the Euler angle (theta) which can be set to 02 or less, and the line which shows an upper limit.
- the attenuation constant ⁇ is set to 0.1 when the IDT electrode is made of Ni and the normalized wavelength thickness of the Si 3 N 4 film is 0.175 or more and less than 0.225. It is a figure showing the line which shows the minimum of Y which is the Euler angle (theta) which can be set to 02 or less, and the line which shows an upper limit.
- FIG. 62 shows that, in the second embodiment, when the IDT electrode is made of Ni, and the wavelength normalized thickness of the Si 3 N 4 film is 0.225 or more and less than 0.275, the attenuation constant ⁇ is set to 0. It is a figure showing the line which shows the minimum of Y which is the Euler angle (theta) which can be set to 02 or less, and the line which shows an upper limit.
- FIG. 1 is a schematic front sectional view of an acoustic wave device according to a first embodiment of the present invention.
- the acoustic wave device 1 has a LiNbO 3 substrate 2.
- An IDT electrode 3 is provided on the LiNbO 3 substrate 2.
- An aluminum nitride film 4 is provided on the LiNbO 3 substrate 2 so as to cover the IDT electrode 3.
- the elastic wave device 1 of the present embodiment uses leaky elastic waves that propagate through the LiNbO 3 substrate 2. As described above, when a leaky elastic wave is used, a higher sound speed can be achieved. In addition, in the present embodiment, since the aluminum nitride film 4 is laminated as the high sound velocity film, the sound velocity can be further increased.
- the inventor of the present application configures the IDT electrode with a specific metal, and depending on the type of metal constituting the IDT electrode and the range of the wavelength normalized thickness of the aluminum nitride film, the LiNbO 3 substrate It has been found that if the Euler angle ⁇ is in a specific range, both high sound speed and low loss can be achieved, and the present invention has been achieved.
- the metal constituting the IDT electrode 3 is made of a metal mainly composed of one kind of material selected from the group consisting of Cu, Al, Au, Pt, and Ni.
- the “main body” refers to the metal that is the main by weight.
- a very thin film such as an adhesion layer or a protective layer may be laminated.
- the Euler angles of the LiNbO 3 substrate 2 are (0 ° ⁇ 5 °, ⁇ , 0 ° ⁇ 5 °).
- the wavelength normalized thickness of the IDT electrode 3 is X and the Euler angle ⁇ is Y
- Y which is the Euler angle ⁇ according to the type of metal and the wavelength normalized thickness range of the aluminum nitride film 4. Is within one of the ranges shown in Tables 11 to 15 below. As a result, high sound speed and low loss can be achieved. This will be described more specifically below.
- FIG. 2 is a diagram illustrating the relationship between ⁇ and the acoustic velocity of leaky elastic waves and Rayleigh waves propagating through LiNbO 3 at the Euler angles (0 °, ⁇ , 0 °) of the LiNbO 3 substrate 2.
- the leaky elastic wave is indicated by LSAW.
- Vf represents the sound velocity with the substrate surface open
- Vm represents the metallized state, that is, the sound velocity with the substrate surface short-circuited.
- the acoustic velocity of the leaky elastic wave is higher than that of the Rayleigh wave in the wide range of ⁇ from 0 ° to 180 °. Therefore, it can be seen that the acoustic velocity can be increased by using leaky elastic waves. However, it can be seen that the sound velocity of the leaky elastic wave changes as the Euler angle ⁇ changes.
- the inventor of the present application changed the Euler angle ⁇ of the LiNbO 3 substrate to determine the change in the sound velocity attenuation constant ⁇ (dB / ⁇ ) in the open state and the short-circuit state.
- the results are shown in FIG.
- ⁇ is substantially 0 at the vicinity of 154 °, and the attenuation constant ⁇ is minimal.
- FIG. 4 is a diagram showing the relationship between the thickness of Cu and the speed of sound in a structure in which an IDT electrode 3 made of Cu is provided on a LiNbO 3 substrate with Euler angles (0 °, 94 °, 0 °).
- fa corresponds to the anti-resonance frequency, that is, the sound speed in the open state
- fr corresponds to the sound speed of the resonance frequency, that is, the sound speed in the short-circuited state.
- a broken line A indicates the sound speed of a slow transverse wave.
- the sound speed decreases as the Cu thickness increases. It is considered that the propagating wave is a Love wave at a portion where the sound velocity is lower than the shear wave velocity A, that is, 4080 m / sec.
- FIG. 5 shows a case where an IDT electrode 3 made of Cu having a wavelength normalized thickness of 0.2 is laminated on a LiNbO 3 substrate with Euler angles (0 °, 131 °, 0 °), and a high sound velocity film is obtained.
- the sound speed increases as the thickness of the aluminum nitride film increases.
- the velocity is 4080 m / sec or more, that is, at a velocity higher than the slow transverse wave velocity, it is considered that the propagating wave is a leaky elastic wave.
- ⁇ and the wavelength normalized thickness of the aluminum nitride film are 0.05, 0.10, 0.15,
- the relationship with the attenuation constant ⁇ of the sound speed Vf in the open state was obtained.
- the wavelength normalized thickness is a value obtained by standardizing the thickness with a wavelength determined by the period of the electrode finger of the IDT electrode.
- the IDT electrode 3 was made of Cu, and its wavelength normalized thickness was fixed at 0.08.
- the attenuation constant ⁇ can be reduced by selecting the Euler angle ⁇ according to the wavelength normalized thickness of the AlN film.
- the attenuation constant is required to be 0.02 or less. Therefore, it can be seen that the Euler angle ⁇ should be set within a specific range in accordance with the thickness of the AlN film in order to set the attenuation constant ⁇ to 0.02 or less.
- a broken line B in FIG. 6 indicates a portion where the attenuation constant ⁇ is 0.02. Therefore, when the thickness of the AlN film is, for example, 0.25, it can be seen that the damping constant ⁇ can be 0.02 or less if the Euler angle ⁇ is in the range of 97 ° to 163 °.
- FIG. 7 shows the results when the IDT electrode is formed of an Au film having a wavelength normalized thickness of 0.038 instead of Cu.
- FIG. 8 shows the results when the IDT electrode 3 is formed of a Pt film having a wavelength normalized thickness of 0.034 instead of Cu.
- FIG. 9 shows the results when the IDT electrode 3 is formed of a Ni film having a normalized wavelength thickness of 0.08.
- FIG. 10 shows the results when the IDT electrode is formed of an Al film having a wavelength normalized thickness of 0.264 instead of Cu.
- the Euler angle ⁇ is set according to the wavelength normalized thickness of the AlN film. It can be seen that if the specific range is set, the attenuation constant ⁇ can be 0.02 or less.
- the inventor of the present application determines the attenuation constant ⁇ by setting the Euler angle ⁇ to a specific range for each of the types of metal constituting the IDT electrode and the wavelength normalized thickness range of the aluminum nitride film.
- the range which can be 0.02 or less was found. This is the range shown in Tables 11 to 15 described above. For example, the case where an IDT electrode made of Cu in Table 11 is used will be described as an example.
- the lower line shown in FIG. 11 is a line represented by the formula indicating the lower limit.
- the upper line of FIG. 11 is a line represented by the formula which shows the said upper limit. Therefore, the Euler angle ⁇ may be selected in accordance with the wavelength normalized thickness of the AlN film so that it is in the range from the line indicating the lower limit of FIG. 11 to the line indicating the upper limit.
- the attenuation constant ⁇ is 0.02 or less depending on the wavelength normalized thickness range of the AlN film and the wavelength normalized thickness X of Cu. Find the range.
- 12 to 15 are diagrams showing lines indicating the upper and lower limits of the remaining combinations shown in Table 11, respectively.
- the Euler angle ⁇ may be set within a specific range so as to be equal to or higher than the lower line indicating the lower limit and lower than the upper line indicating the upper limit.
- the attenuation constant ⁇ can be set to 0.02 or less.
- the lower limit value of Y in Table 12 is 132-13X-18
- the upper limit value is 132-13X + 18.
- ⁇ 18 is the lower limit value of Y and +18 is the upper limit value.
- the attenuation constant ⁇ can be made 0.02 or less if Y is selected so as to be in the specific range shown in Table 12.
- the range of Y is selected according to the wavelength normalized thickness of the AlN film and the wavelength normalized thickness X of the IDT electrode so as to be within the ranges shown in Table 13 above. do it.
- the lower line in the graph is a line represented by the lower limit expression of Y in Table 13
- the upper line is a line represented by the upper limit expression of Y.
- the above-mentioned lower limit value or more and the upper limit value or less are made according to the wavelength normalized thickness range of the AlN film and according to the wavelength normalized thickness of the IDT electrode made of Au.
- Y that is, Euler angle ⁇ may be selected.
- the attenuation constant ⁇ can be made 0.02 or less.
- the Y range is selected according to the wavelength normalized thickness of the AlN film and the wavelength normalized thickness X of the IDT electrode so as to be within the ranges shown in Table 14 above. do it.
- the lower line in the graph is a line represented by the lower limit expression of Y in Table 14, and the upper line is a line represented by the upper limit expression of Y.
- the range is not less than the above lower limit value and not more than the upper limit value according to the wavelength normalized thickness range of the Pt IDT electrode according to the wavelength normalized thickness range of the AlN film.
- Y that is, Euler angle ⁇ may be selected.
- the attenuation constant ⁇ can be made 0.02 or less.
- the range of Y is selected according to the wavelength normalized thickness of the AlN film and the wavelength normalized thickness X of the IDT electrode so as to be within the ranges shown in Table 15 above. do it.
- the lower line in the graph is a line represented by the lower limit expression of Y in Table 15, and the upper line is a line represented by the upper limit expression of Y.
- the above-mentioned lower limit value or more and the upper limit value or less are made according to the wavelength normalized thickness range of the AlN film and according to the wavelength normalized thickness of the IDT electrode made of Ni.
- Y that is, Euler angle ⁇ may be selected.
- the attenuation constant ⁇ can be made 0.02 or less.
- the aluminum nitride film 4 is used as the high sound velocity film.
- a silicon nitride film is used as the high sound velocity film instead of the aluminum nitride film. Since the structure of the elastic wave device of the second embodiment is the same in other respects, the structure shown in FIG. 1 is also used in the second embodiment.
- a Si 3 N 4 film is used as the silicon nitride film, the present invention is not limited to this, and it may be SixNy (x and y are integers).
- FIG. 32 shows that in the second embodiment, the Euler angles of the LiNbO 3 substrate are (0 °, 160 °, 0 °), the IDT electrode is made of Cu with a wavelength normalized thickness of 0.22, and Si 3 N in 4 film was laminated structure is a diagram showing the wavelength normalized thickness of the Si 3 N 4 film, the relationship between the speed of sound.
- the speed of sound can be increased by increasing the thickness of the Si 3 N 4 film.
- the sound velocity in the open state can be made higher than 4080 m / sec, which is a slow transverse wave velocity, by increasing the film thickness of the Si 3 N 4 film. Therefore, in the second embodiment, since the Si 3 N 4 film is laminated so as to cover the IDT electrode, the speed of sound can be increased.
- the present inventors even in the structure with the Si 3 N 4 film, and ⁇ of the Euler angles of the LiNbO 3 substrate, the Si 3 N 4 film by changing the wavelength normalized thickness was determined the change of the attenuation constant ⁇ . The results are shown in FIGS.
- the wavelength normalized thickness of the Si 3 N 4 film is set to 0.05, 0.10, 0.15, 0.20, or 0.25, and the Euler angle ⁇ is changed to change each IDT electrode.
- the change of attenuation constant (alpha) at the time of fixing the metal which comprises and wavelength standardization thickness is shown.
- the attenuation constant ⁇ changes greatly as the Euler angle ⁇ changes. It can also be seen that in each case, the damping constant ⁇ can be 0.02 or less if the Euler angle ⁇ is in a specific range.
- FIG. 34 shows the results when the IDT electrode is made of Au and the wavelength normalized thickness is 0.038.
- FIG. 35 shows the results when the IDT electrode is made of Pt and the wavelength normalized thickness is 0.034.
- FIG. 36 shows the results when the IDT electrode is made of Ni and the wavelength normalized thickness is 0.08.
- FIG. 37 shows the results when the IDT electrode is made of Al and the wavelength normalized thickness is 0.264.
- the inventor of the present application in the case of using a silicon nitride film, similarly to the case of using an aluminum nitride film, the wavelength standardized thickness range of the Si 3 N 4 film and the metal constituting the IDT electrode It was confirmed that the attenuation constant ⁇ could be set to 0.02 or less if Y, which is the Euler angle ⁇ , was set in a specific range according to the wavelength standardized thickness X. The result is one of the ranges shown in Tables 16 to 20 below.
- the Euler angle ⁇ is set to be not less than the lower limit and not more than the upper limit shown in Table 16.
- Y is 111-498X + 41204X 2 -506285X 3 + 2.1 ⁇ 10 6 X 4 -2.9X It may be 5 or more and 150 + 376X-1867X 2 + 3151X 3 or less.
- the line shown in the lower part of FIG. 38 is a line represented by this lower limit expression, and the upper line is a line represented by the upper limit expression.
- the value of Euler angle ⁇ is not less than the lower limit and not more than the upper limit so that the range is not less than the lower line and not more than the upper line. You can see that Thereby, the attenuation constant ⁇ can be made 0.02 or less.
- the lower and upper lines shown in FIG. 39 indicate the lower limit value of Y and the upper limit value when the wavelength normalized thickness of the Si 3 N 4 film in Table 16 is 0.075 or more and less than 0.125. It is a line represented by a formula.
- the lower line in FIG. 40 indicates the lower limit value of Y that sets the attenuation constant ⁇ to 0.02 or less when the wavelength normalized thickness of the Si 3 N 4 film is 0.125 or more and less than 0.175. It is a line represented by the formula which shows.
- the upper line is a line indicated by the expression for the upper limit value of Y.
- the Euler angle is set according to the thickness of the IDT electrode made of Cu so that it is above the lower line and below the upper line. What is necessary is just to select Y which is (theta). Thereby, the attenuation constant ⁇ can be made 0.02 or less.
- the lower limit value of Y when the wavelength normalized thickness of the Si 3 N 4 film of Table 16 is 0.175 or more and less than 0.225 or 0.225 or more and less than 0.275, respectively.
- a line represented by an expression of an upper limit value of Y is 0.175 or more and less than 0.225 or 0.225 or more and less than 0.275.
- the attenuation constant ⁇ can be made 0.02 or less.
- Y which is the Euler angle ⁇
- Y is set to be not less than the lower limit value and not more than the upper limit value shown in Table 17.
- Y may be 106 + 124X ⁇ 204X 2 or more and 163 ⁇ 105X + 714X 2 ⁇ 1122X 3 or less.
- the line shown in the lower part of FIG. 43 is a line represented by this lower limit expression, and the upper line is a line represented by the upper limit expression.
- the Euler angle ⁇ may be set to the lower limit value or more and the upper limit value or less. I understand that. Thereby, the attenuation constant ⁇ can be made 0.02 or less.
- the lower and upper lines shown in FIG. 44 indicate the lower limit value of Y and the upper limit value when the wavelength normalized thickness of the Si 3 N 4 film in Table 17 is 0.075 or more and less than 0.125. It is a line represented by a formula.
- the lower line in FIG. 45 indicates the lower limit value of Y that sets the attenuation constant ⁇ to 0.02 or less when the wavelength normalized thickness of the Si 3 N 4 film is 0.125 or more and less than 0.175. It is a line represented by the formula which shows.
- the upper line is a line indicated by the expression for the upper limit value of Y.
- the lower limit value of Y when the wavelength normalized thickness of the Si 3 N 4 film in Table 17 is 0.175 or more and less than 0.225 or 0.225 or more and less than 0.275, respectively.
- a line represented by an expression of an upper limit value of Y is 0.175 or more and less than 0.225 or 0.225 or more and less than 0.275.
- the attenuation constant ⁇ can be set to 0.02 or less.
- Y which is the Euler angle ⁇
- Y is set to be not less than the lower limit value and not more than the upper limit value shown in Table 18.
- Y is 138.8 ⁇ 521.5X + 59626X 2 ⁇ 1.6 ⁇ 10 6 X 3 +9. 7 ⁇ 10 6 X 4 or more, 154.6 + 323X-1005X 2 or less may be used.
- the Euler angle ⁇ should be set to the lower limit value or more and the upper limit value or less. I understand that. Thereby, the attenuation constant ⁇ can be made 0.02 or less.
- the lower and upper lines shown in FIG. 49 indicate the lower limit value of Y and the upper limit value when the wavelength normalized thickness of the Si 3 N 4 film in Table 18 is 0.075 or more and less than 0.125. It is a line represented by a formula.
- the line shown below in FIG. 50 indicates the lower limit value of Y that sets the attenuation constant ⁇ to 0.02 or less when the wavelength normalized thickness of the Si 3 N 4 film is 0.125 or more and less than 0.175. It is a line represented by the formula which shows.
- the upper line is a line indicated by the expression for the upper limit value of Y.
- the constant ⁇ can be 0.02 or less.
- the Euler angle ⁇ is set to be not less than the lower limit and not more than the upper limit shown in Table 19.
- the wavelength normalized thickness of the Si 3 N 4 film is 0.02 or more and less than 0.075
- Y is 137.8 + 1045.9X-35270X 2 + 182370X 3 or more
- 178.8-459.9X + 2654 .2X may be set to 2 or less.
- the line shown in the lower part of FIG. 53 is a line represented by this lower limit expression
- the upper line is a line represented by the upper limit expression.
- the value of Euler angle ⁇ may be set to the lower limit value or more and the upper limit value or less in accordance with the wavelength standardized thickness of the IDT electrode made of Pt so as to be in the range from the lower line to the upper line. I understand that. Thereby, the attenuation constant ⁇ can be made 0.02 or less.
- the lower and upper lines shown in FIG. 54 indicate the lower limit value of Y and the upper limit value when the wavelength normalized thickness of the Si 3 N 4 film in Table 19 is 0.075 or more and less than 0.125. It is a line represented by a formula.
- the lower line in FIG. 55 indicates the lower limit value of Y that sets the attenuation constant ⁇ to 0.02 or less when the wavelength normalized thickness of the Si 3 N 4 film is 0.125 or more and less than 0.175. It is a line represented by the formula which shows.
- the upper line is a line indicated by the expression for the upper limit value of Y.
- the lower limit value of Y when the wavelength normalized thickness of the Si 3 N 4 film of Table 19 is 0.175 or more and less than 0.225 or 0.225 or more and less than 0.275, respectively.
- a line represented by an expression of an upper limit value of Y is 0.175 or more and less than 0.225 or 0.225 or more and less than 0.275.
- the damping constant ⁇ is set by selecting the Euler angle ⁇ to be in the range from the lower line to the upper line as shown in FIGS. It can be 0.02 or less.
- the Euler angle ⁇ is set to be not less than the lower limit and not more than the upper limit shown in Table 20.
- the wavelength normalized thickness of the Si 3 N 4 film is 0.02 or more and less than 0.075
- Y is 77.39 + 889X-10413X 2 + 39192X 3 ⁇ 48758X 4 or more, 133.7 + 570.1X ⁇ 2561X 2 + 39863587X 3 or less may be used.
- the Euler angle ⁇ value may be set to the lower limit value or more and the upper limit value or less. I understand that. Thereby, the attenuation constant ⁇ can be made 0.02 or less.
- the lower and upper lines shown in FIG. 59 indicate the lower limit value of Y and the upper limit value when the wavelength normalized thickness of the Si 3 N 4 film in Table 20 is 0.075 or more and less than 0.125. It is a line represented by a formula.
- the lower line in FIG. 60 indicates the lower limit value of Y that sets the attenuation constant ⁇ to 0.02 or less when the wavelength normalized thickness of the Si 3 N 4 film is 0.125 or more and less than 0.175. It is a line represented by the formula which shows.
- the upper line is a line indicated by the expression for the upper limit value of Y.
- the lower limit value of Y when the wavelength normalized thickness of the Si 3 N 4 film of Table 20 is 0.175 or more and less than 0.225 or 0.225 or more and less than 0.275, respectively.
- a line represented by an expression of an upper limit value of Y is 0.175 or more and less than 0.225 or 0.225 or more and less than 0.275.
- the attenuation constant ⁇ can be 0.02 or less.
- acoustic wave device 2 LiNbO 3 substrate 3 .
- IDT electrode 4 Aluminum nitride film
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Abstract
Description
従って、従来は、漏洩弾性波を用いて、かつ、高音速膜を積層することにより音速を高めることが試みられている。しかしながら、高音速膜を積層した構造では、音速が高くなるので漏洩弾性波が出力され、減衰定数が大きくなるという問題があった。
IDT電極がAlからなる場合には、Yを、前述した表12に示すYの下限と上限との範囲内にすればよい。すなわち、AlからなるIDT電極3上に、AlN膜を積層した構造において、AlN膜の厚み範囲と、AlからなるIDT電極の波長規格化厚みXとに応じて、オイラー角のθであるYを選択すればよい。図16におけるY=154-17Xは、AlN膜の厚みが0.02以上、0.075未満の場合の上限と下限の中心となる線である。表12では、AlN膜の厚みが0.02以上、0.075未満の場合、Yの下限は154-17X-18であり、上限は154-17X+18である。図16のY=154-17Xは、この上限と下限との中央を示す線である。
IDT電極がAuからなる場合には、前述した表13に示す各範囲内となるようにAlN膜の波長規格化厚みと、IDT電極の波長規格化厚みXとに応じて、Yの範囲を選択すればよい。
IDT電極がPtからなる場合には、前述した表14に示す各範囲内となるようにAlN膜の波長規格化厚みと、IDT電極の波長規格化厚みXとに応じて、Yの範囲を選択すればよい。
IDT電極がNiからなる場合には、前述した表15に示す各範囲内となるようにAlN膜の波長規格化厚みと、IDT電極の波長規格化厚みXとに応じて、Yの範囲を選択すればよい。
上記第1の実施形態では、高音速膜として窒化アルミニウム膜4が用いられていた。本発明の第2の実施形態では、高音速膜として、窒化アルミニウム膜に代えて窒化ケイ素膜が用いられる。第2の実施形態の弾性波装置の構造は、その他の点において同様であるため、図1に示した構造を第2の実施形態においても援用することとする。なお、ここでは、窒化ケイ素膜として、Si3N4膜を用いたがこれに限られるものではなく、SixNy(x、yは整数)であればよい。
IDT電極がCuからなる場合、表16に示す各Si3N4膜の波長規格化厚み範囲に応じて、オイラー角のθであるYを表16に示す下限値以上、上限値以下とすればよい。例えば表16において、Si3N4膜の波長規格化厚みが0.02以上、0.075未満の場合、Yは、111-498X+41204X2-506285X3+2.1×106X4-2.9X5以上、150+376X-1867X2+3151X3以下とすればよい。図38の下方に示す線が、この下限値の式で表される線であり、上方の線が上限値の式で表される線である。
IDT電極がAlからなる場合、表17に示す各Si3N4膜の波長規格化厚み範囲に応じて、オイラー角のθであるYを表17に示す下限値以上、上限値以下とすればよい。例えば表17において、Si3N4膜の波長規格化厚みが0.02以上、0.075未満の場合、Yは、106+124X-204X2以上、163-105X+714X2-1122X3以下とすればよい。図43の下方に示す線が、この下限値の式で表される線であり、上方の線が上限値の式で表される線である。従って、上記下方の線以上、上方の線以下の範囲とするようにAlからなるIDT電極の波長規格化厚みに応じて、オイラー角のθの値を下限値以上、上限値以下とすればよいことがわかる。それによって、減衰定数αを0.02以下とすることができる。
IDT電極がAuからなる場合、表18に示す各Si3N4膜の波長規格化厚み範囲に応じて、オイラー角のθであるYを表18に示す下限値以上、上限値以下とすればよい。例えば表18において、Si3N4膜の波長規格化厚みが0.02以上、0.075未満の場合、Yは、138.8-521.5X+59626X2-1.6×106X3+9.7×106X4以上、154.6+323X-1005X2以下とすればよい。図48の下方に示す線が、この下限値の式で表される線であり、上方の線が上限値の式で表される線である。従って、上記下方の線以上、上方の線以下の範囲とするようにAuからなるIDT電極の波長規格化厚みに応じて、オイラー角のθの値を下限値以上、上限値以下とすればよいことがわかる。それによって、減衰定数αを0.02以下とすることができる。
IDT電極がPtからなる場合、表19に示す各Si3N4膜の波長規格化厚み範囲に応じて、オイラー角のθであるYを表19に示す下限値以上、上限値以下とすればよい。例えば表19において、Si3N4膜の波長規格化厚みが0.02以上、0.075未満の場合、Yは、137.8+1045.9X-35270X2+182370X3以上、178.8-459.9X+2654.2X2以下とすればよい。図53の下方に示す線が、この下限値の式で表される線であり、上方の線が上限値の式で表される線である。従って、上記下方の線以上、上方の線以下の範囲とするようにPtからなるIDT電極の波長規格化厚みに応じて、オイラー角のθの値を下限値以上、上限値以下とすればよいことがわかる。それによって、減衰定数αを0.02以下とすることができる。
IDT電極がNiからなる場合、表20に示す各Si3N4膜の波長規格化厚み範囲に応じて、オイラー角のθであるYを表20に示す下限値以上、上限値以下とすればよい。例えば表20において、Si3N4膜の波長規格化厚みが0.02以上、0.075未満の場合、Yは、77.39+889X-10413X2+39192X3-48758X4以上、133.7+570.1X-2561X2+39863587X3以下とすればよい。図58の下方に示す線が、この下限値の式で表される線であり、上方の線が上限値の式で表される線である。従って、上記下方の線以上、上方の線以下の範囲とするようにNiからなるIDT電極の波長規格化厚みに応じて、オイラー角のθの値を下限値以上、上限値以下とすればよいことがわかる。それによって、減衰定数αを0.02以下とすることができる。
2…LiNbO3基板
3…IDT電極
4…窒化アルミニウム膜
Claims (2)
- LiNbO3基板と、
前記LiNbO3基板上に設けられたIDT電極と、
前記IDT電極を覆うように前記LiNbO3基板上に設けられた窒化アルミニウム膜とを備え、前記LiNbO3基板を伝搬する漏洩弾性波を利用した弾性波装置であって、
前記IDT電極が、Cu、Al、Au、Pt及びNiからなる群から選択した1種の材料を主体とする金属からなり、前記LiNbO3基板のオイラー角を(0°±5°,θ,0°±5°)とし、前記IDT電極の波長規格化厚みをX、前記オイラー角のθをYとしたときに、前記IDT電極を構成している金属の種類、及び前記窒化アルミニウム膜の波長規格化厚みの範囲に応じて、前記オイラー角のθであるYが下記の表1~表5に示すいずれかの範囲とされている弾性波装置。
- LiNbO3基板と、
前記LiNbO3基板上に設けられたIDT電極と、
前記IDT電極を覆うように前記LiNbO3基板上に設けられた窒化ケイ素膜とを備え、前記LiNbO3基板を伝搬する漏洩弾性波を利用した弾性波装置であって、
前記IDT電極が、Cu、Al、Au、Pt及びNiからなる群から選択した1種の材料を主体とする金属からなり、前記LiNbO3基板のオイラー角を(0°±5°,θ,0°±5°)とし、前記IDT電極の波長規格化厚みをX、前記オイラー角のθをYとしたときに、前記IDT電極を構成している金属の種類、及び前記窒化ケイ素膜の波長規格化厚みの範囲に応じて、前記オイラー角のθであるYが下記の表6~表10に示すいずれかの範囲とされている弾性波装置。
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
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DE112015001209.5T DE112015001209B4 (de) | 2014-03-13 | 2015-02-20 | Vorrichtung für elastische Wellen |
CN201580007259.1A CN105981297B (zh) | 2014-03-13 | 2015-02-20 | 弹性波装置 |
JP2016507425A JP6304369B2 (ja) | 2014-03-13 | 2015-02-20 | 弾性波装置 |
US15/230,529 US10177739B2 (en) | 2014-03-13 | 2016-08-08 | Elastic wave device |
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JP2011166259A (ja) * | 2010-02-05 | 2011-08-25 | Murata Mfg Co Ltd | 弾性表面波装置 |
JP2013168864A (ja) * | 2012-02-16 | 2013-08-29 | Nippon Dempa Kogyo Co Ltd | 弾性表面波素子及び電子部品 |
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JP3841053B2 (ja) * | 2002-07-24 | 2006-11-01 | 株式会社村田製作所 | 弾性表面波装置及びその製造方法 |
JP4419961B2 (ja) * | 2003-12-16 | 2010-02-24 | 株式会社村田製作所 | 弾性境界波装置 |
DE112005001677B4 (de) * | 2004-07-26 | 2009-11-12 | Murata Manufacturing Co., Ltd., Nagaokakyo | Oberflächenwellenbauelement |
DE112007000874B4 (de) * | 2006-04-24 | 2012-11-29 | Murata Manufacturing Co., Ltd. | Oberflächenwellenbauelement |
WO2008004408A1 (fr) * | 2006-07-05 | 2008-01-10 | Murata Manufacturing Co., Ltd. | Dispositif d'onde de surface élastique |
JP4931615B2 (ja) | 2007-01-19 | 2012-05-16 | 京セラ株式会社 | 弾性表面波装置及び通信装置 |
WO2010032383A1 (ja) * | 2008-09-22 | 2010-03-25 | 株式会社村田製作所 | 弾性境界波装置 |
JPWO2010116783A1 (ja) * | 2009-03-30 | 2012-10-18 | 株式会社村田製作所 | 弾性波装置 |
KR101623099B1 (ko) * | 2010-12-24 | 2016-05-20 | 가부시키가이샤 무라타 세이사쿠쇼 | 탄성파 장치 및 그 제조 방법 |
JP5617936B2 (ja) * | 2011-01-19 | 2014-11-05 | 株式会社村田製作所 | 弾性表面波装置 |
JP6601503B2 (ja) * | 2015-10-23 | 2019-11-06 | 株式会社村田製作所 | 弾性波装置、高周波フロントエンド回路及び通信装置 |
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JP2011166259A (ja) * | 2010-02-05 | 2011-08-25 | Murata Mfg Co Ltd | 弾性表面波装置 |
JP2013168864A (ja) * | 2012-02-16 | 2013-08-29 | Nippon Dempa Kogyo Co Ltd | 弾性表面波素子及び電子部品 |
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US20160344369A1 (en) | 2016-11-24 |
DE112015001209T5 (de) | 2016-12-15 |
JP6304369B2 (ja) | 2018-04-04 |
CN105981297B (zh) | 2018-09-14 |
DE112015001209B4 (de) | 2021-06-24 |
JPWO2015137090A1 (ja) | 2017-04-06 |
CN105981297A (zh) | 2016-09-28 |
US10177739B2 (en) | 2019-01-08 |
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