JP2001267884A - Surface acoustic wave element and forming method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the surface acoustic wave element of a high frequency, high performance and high stability and to provide the forming method. SOLUTION: A layer 33 constituted of crystal, a layer 32 constituted of a piezoelectric material different from crystal, a layer 31 constituted of a non- piezoelectric material and electrodes 34 are laminated. At least one of the layers is formed by connection. Connection onto the electrodes 34 is performed after a material similar to a material to be connected is previously deposited on the electrodes by the film thickness of not less than the thickness of the electrode. A connection temperature is set to be not more than the phase transfer temperature of crystal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface acoustic wave device used in the field of information communication and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventional surface acoustic wave devices are roughly classified into two types, one using a single crystal of a piezoelectric material and one having a thin film made of a piezoelectric material formed on a substrate. Typical single crystals are quartz, lithium niobate (hereinafter, LiNbO ₃ ), lithium tantalate (hereinafter, Li
TaO ₃ ). On the other hand, as a surface acoustic wave device using a thin film, Jpn. J. Appl. Phys
s. Vol. 32 (1993) pp. 2337-234
No. 0, a zinc oxide (hereinafter ZnO) thin film formed on a sapphire substrate, or Jpn.
J. Appl. Phys. Vol. 32 (1993) p
p. Examples thereof include those obtained by forming a LiNbO ₃ thin film on a sapphire substrate as described in L745-L747.

The performance of the surface acoustic wave device can be applied to a device having a larger electromechanical coupling coefficient (hereinafter, k ² ), a device having better temperature characteristics, and a higher frequency with the remarkable development of the communication field. The demand for things is growing. The surface acoustic wave device can be applied to both a filter and an oscillator, but particularly when used in an oscillator, the temperature characteristics become important. In addition, high-order multiplication type, phase synchronization type,
Although there are direct types and the like, direct types are desirable for miniaturization of equipment, and for that purpose, high frequency is also important. Also, a high k ² is desired for the filter. A material having a high sound speed is desired for increasing the frequency of both the filter and the oscillator.

[0004] Regarding the temperature characteristics, see, for example, "Surface Wave Devices and Their Applications", edited by Electronic Materials Industry Association, 1978, p.
As stated in p106~108, ZnO and SiO ₂ in which the sign of the group delay time temperature characteristic TCD different positive and negative
There is a possibility that it can be improved by stacking such as. This is also described in JP-A-6-164294 or JP-A-9-130192. JP-A-6-164
In H.294, a diamond thin film is formed on a Si substrate, and a piezoelectric thin film and a silicon dioxide protective film are further formed thereon, thereby increasing the frequency and improving k ² . In Japanese Patent Application Laid-Open No. Hei 9-130192, ZnO on a quartz substrate is used.
K ² by standardizing the film thickness of the
Is also being improved.

On the other hand, J. A. Appl. Phys. , Vo
l. 60, (1986) pp 2987-2989, a technique for easily and directly bonding silicon substrates to each other has been developed and applied. As an application example, Proc. IEEE Ultrason. Sym
p. As described in (1994) pp 1045-1049, a one-chip crystal oscillator in which a crystal unit and an oscillation circuit are integrated by directly bonding a crystal and a silicon substrate has also been manufactured.

[0006]

However, the conventional surface acoustic wave device has the following problems.

First, in a surface acoustic wave device using a single crystal, characteristics such as sound speed, k ^2, and temperature coefficient are values inherent to the material, and are determined by the plane orientation to be cut. The materials published so far have their advantages and disadvantages, and thus, depending on the purpose of use at the moment, the materials are selectively used. For example, in the case of a filter that requires a wide frequency band and low loss, a LiNbO ₃ having a large k ² is used. On the other hand, if the frequency may be a narrow band but a stable temperature characteristic is required, Quartz having a small temperature coefficient is used. However, quartz has a low sound speed and is not good at raising the frequency, and it is difficult to use it in the GHz band. Therefore,
It is difficult to produce a direct oscillator or a filter at a high frequency. That is, it is difficult to pattern the electrodes because the electrode interval is small. LiTaO ₃ , whose k ² and temperature coefficient are between LiNbO ₃ and quartz, respectively, plays an intermediate role. However, at present, there is a demand for a surface acoustic wave device having a high sound speed, a large k ^{2, and a} small temperature coefficient, and there is no material satisfying these characteristics. Therefore, when a single crystal is used, one has to wait until a new material is discovered. On the other hand, the surface acoustic wave element using a thin film, by forming a thin film on a fast acoustic velocity substrate, improvement of are grave higher frequency and k ^2, and is also possible with the expected improvement in the temperature characteristics. In other words, there is a possibility that characteristics that are not governed by the material-specific values may be obtained by controlling the combination of the materials of the substrate and the thin film to be used or controlling the orientation of the thin film. However, at present, none satisfying desired characteristics has been obtained. S such as crystal
The temperature characteristics of, for example, a LiNbO ₃ thin film on sapphire using a material other than a material containing iO ₂ as a main component are not so much improved. On the other hand, when a diamond thin film as described in JP-A-6-164294 is used for a substrate, a high sound velocity can be obtained, but the surface flatness of the diamond thin film poses a problem. The surface flatness of the substrate is important because it affects the element characteristics. Currently, its surface is polished and used, but diamond is hard and difficult to process. Although polishing technology has advanced, diamond thin films are also polycrystalline,
It is clearly inferior to the surface flatness of other single crystal substrates. Further, the crystallinity of the piezoelectric thin film formed thereon is also important in terms of element characteristics and reliability, but it is difficult to form a high quality piezoelectric thin film on a polycrystalline diamond thin film. As the piezoelectric thin film, an epitaxial film, more preferably, a single crystal is desirable. Further, since the diamond thin film substrate is hard, it is difficult to cut it into chip sizes.
On the other hand, Japanese Patent Application Laid-Open No. Hei 9-130192 states that a material having good temperature characteristics can be obtained, but it is insufficient for increasing the frequency up to the GHz band, and it is difficult to use a wave having a high sound speed. Load is applied to processing.

[0008] Further, there is no report on the application of direct bonding to surface acoustic wave devices. In the case of crystal oscillators and the like which have been reported in the past, there is no example using a high-sonic material for high frequency, and only materials that are relatively easy to join are used. Further, in the case of the surface acoustic wave device, when bonding directly on the comb-tooth electrode, a step due to the electrode causes a problem of bonding. Further, quartz has a phase transition temperature. If the process temperature is higher than the phase transition temperature, cracks or defects may be introduced into the quartz, which may lower the yield.

SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned problems, and it is an object of the present invention to provide a surface acoustic wave device which can cope with a higher frequency, has a high k ² and has a good temperature characteristic, and a surface having a step. The present invention also provides a method of manufacturing a surface acoustic wave device which can be directly bonded and has a good yield.

[0010]

The surface acoustic wave device of the present invention has a layer made of quartz, a layer made of a piezoelectric material different from quartz, a layer made of a non-piezoelectric material, and an electrode. At least one is formed by bonding. More specifically, a layer made of quartz, a layer made of a piezoelectric material other than quartz, a layer made of a non-piezoelectric material, and an electrode are stacked, the order of stacking the layers is arbitrary, and At least one is a surface acoustic wave device characterized by being formed by bonding.

In a preferred embodiment of the surface acoustic wave device according to the present invention, the non-piezoelectric material has a Young's modulus of 3.5 × 10 ¹² dyne / cm ² or more and a density of 4 g / cm ³ or less. It is.

In a preferred embodiment of the surface acoustic wave device according to the present invention, each of the layer made of quartz, the layer made of a piezoelectric material different from quartz (other than quartz) and the layer made of a non-piezoelectric material is an epitaxial film or Consists of a single crystal.

Further, in a preferred embodiment, the electrode is formed in contact with at least one of the piezoelectric material layer and the layer made of quartz.

According to the surface acoustic wave device having the above structure, since the non-piezoelectric material is hard, a high sound velocity can be obtained by forming the electrode in contact with at least one of the piezoelectric material layer and the layer made of quartz. The frequency can be increased. Further, since the signs of the temperature coefficients of the quartz and the piezoelectric material are opposite, they are canceled out by combining them, and a good temperature characteristic can be obtained. Furthermore, if a material having a high k ² is used for the piezoelectric material, a high k ² can be expected. Further, by using an epitaxial film or a single crystal for each layer, propagation loss of surface acoustic waves can be suppressed, and characteristics with good reproducibility can be obtained.

The method of manufacturing a surface acoustic wave device according to the present invention comprises a layer made of quartz, a layer made of a piezoelectric material different from quartz, a layer made of a non-piezoelectric material, and electrodes (specifically, The order in which the layers are stacked and the layers are stacked is arbitrary), and at least one of the layers is a method for manufacturing a surface acoustic wave device formed by bonding, and bonding another member to the electrode. Is performed after depositing the same material as the material to be bonded on the electrode in advance to a thickness equal to or greater than that of the electrode, and the bonding is performed at a temperature lower than the phase transition temperature of quartz.

According to the above-described method, a surface acoustic wave device can be obtained with a good yield without directly introducing a defect such as a crack or a crack into the quartz crystal.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings according to embodiments and examples.

Embodiment 1 FIG. 1 is a view showing a cross-sectional structure of a surface acoustic wave device according to Embodiment 1 of the present invention.

In the structure shown in FIG. 1, a layer 1 made of a non-piezoelectric material, a layer 2 made of a piezoelectric material, a layer 3 made of quartz, and a non-piezoelectric material layer 1 and a layer 2 made of a piezoelectric material are formed. It is composed of electrodes 4.

The specific configuration is as follows. Non-piezoelectric
Α-Al as material layer 1_TwoO_ThreeUse a substrate and place Al on it
-Forming a comb electrode 4 made of a Cu alloy,
LiNbO as the piezoelectric material layer 2_ThreeForm a thin film and
Α-SiO as a layer 3 made of quartz_TwoRepresented by
Formed AT-cut quartz single crystal. α-Al_Two
O_ThreeHas a Young's modulus of 3.77 × 10¹²dyne / cm^Twoso
3.93 g / cm density ^ThreeIt is. That is, hard and light
Material. Such materials have a high sound speed. these
For materials that do not satisfy the physical property values, the
Therefore, it is difficult to increase the frequency in the GHz band. On the other hand, LiNbO_Three
Single crystal is k^TwoIs known as a high material of 10% or more
You.

The manufacturing process of the surface acoustic wave device according to the present invention having the above-described structure will be specifically described. First, α-Al ₂ O ₃ (0
01) An Al-Cu alloy thin film was formed on a single crystal substrate, and this was patterned to form a comb electrode. Next, LiNbO ₃ was formed thereon. For the film formation, a laser ablation method using a single target of LiNbO ₃ was used.
During the film formation, the substrate was heated while irradiating the substrate with oxygen plasma, and was grown in situ. From X-ray diffraction and RHEED,
It was confirmed that a (001) oriented LiNbO ₃ epitaxial film was obtained.

Next, LiNbO ₃ was directly bonded to the mirror-polished AT-cut quartz single crystal. Direct bonding is performed by the following method. First, the surface of the LiNbO ₃ thin film to be joined and the surface of the AT-cut quartz single crystal are subjected to a hydrophilization treatment and are superposed. Thereafter, when heat treatment is performed in the atmosphere, water molecules and the like are desorbed from the bonding interface, and the bonding is firmly performed. Here, the heat treatment temperature is set to 400 ° C., but the temperature is not limited to this as long as it is lower than the phase transition temperature of quartz. As described above, the surface acoustic wave device shown in FIG. 1 is manufactured.

The characteristics of the device manufactured by such a method were examined. First, LiNbO ₃ without joining AT-cut quartz
The thickness of the LiNbO ₃ thin film was optimized with the structure of the thin film / electrode / α-Al ₂ O ₃ substrate. Assuming that the thickness of the LiNbO ₃ thin film is H and the wavelength of the surface wave is λ, k ² also increases as H / λ increases, and H / λ is almost saturated at about 0.3. The value at this time was about 15%. On the other hand, the sound speed monotonously decreased as H / λ increased. H
When / λ was 0.1, the sound speed was about 6000 m / s, but when H / λ was 0.3, it was about 5000 m / s. Since the element of this embodiment aims at a high-frequency oscillator, the standardized film thickness H / λ of the LiNbO ₃ thin film is set to 0.1 here, giving priority to the sound speed over k ² . At this time, k ² is about 5%. With this value, you can use it for filters. The temperature coefficient TCF was about -70 ppm / ° C.

Next, device characteristics were evaluated for a structure in which an AT-cut quartz single crystal was bonded on the above structure. The purpose of bonding the crystal is to reduce the absolute value of the temperature coefficient.
To that end, the thickness of the crystal is a very important factor. By repeating the simulation and the experiment and optimizing the thickness of the crystal, a TCF of almost 0 ppm / ° C. was obtained.
In addition, the sound speed is 6000 m / s by joining quartz.
To 6500 m / s, which is more advantageous for higher frequency. Since the optimum thickness of the quartz single crystal changes depending on the thickness of the piezoelectric thin film, it is necessary to select an optimum value according to the thickness. Here, a single crystal of quartz is used. However, since various parameters of the single crystal of quartz are grasped, it is very advantageous to use the amorphous or polycrystal in designing the above element. In addition, since the piezoelectric thin film is also an epitaxial film, and the elements are all composed of a single crystal and an epitaxial film, the loss is smaller and the reproducibility of the element characteristics is better than in the case where a polycrystalline body or a polycrystalline film is used. Was.

As described above, in this embodiment, a surface acoustic wave device which can be sufficiently applied to a high frequency oscillator was obtained. this is,
It can also be applied to filters. The non-piezoelectric material, the piezoelectric material, and the electrodes used here are α-Al ₂ O ₃ , LiNb
It is not limited to O ₃ or Al—Cu alloy. The plane orientation and cut angle of each layer are not limited to these. Also, the positions of the electrodes may be formed on the quartz single crystal.

(Embodiment 2) FIG. 2 is a view showing a sectional structure of a surface acoustic wave device according to Embodiment 2 of the present invention.

The structure of the element is basically the same as that of the first embodiment, but the order of laminating each layer is different. That is, it is composed of a layer 21 made of a non-piezoelectric material, a layer 22 made of quartz, a layer 23 made of piezoelectric material, and an electrode 24 formed between the layer 22 made of quartz and the layer 23 made of piezoelectric material. In such a configuration, the manufacturing method is also different.

The specific configuration is as follows. An α-Al ₂ O ₃ substrate is used as the non-piezoelectric material layer 21, and an AT-cut quartz single crystal is formed thereon as a layer 22 made of quartz, and a comb electrode 24 made of an Al—Cu alloy is formed thereon.
Is formed, and ZnO is further formed thereon as a piezoelectric material layer 23.
A thin film is formed.

A manufacturing process of the surface acoustic wave device according to the present invention having the above-described structure will be specifically described.

First, an Al-Cu alloy thin film was formed on an AT-cut quartz single crystal substrate polished on both sides, and this was patterned to form a comb electrode. Next, a ZnO film is formed thereon. For the film formation, a laser ablation method using a single ZnO target was used. The substrate was heated while irradiating the substrate with oxygen plasma during the film formation, and the film was grown in situ. At this time, the substrate temperature is 55 ° C. or less, which is the transition temperature of quartz crystal.
0 ° C. X-ray diffraction confirmed that a (001) oriented ZnO film was obtained. Although the AT-cut quartz and ZnO have a large lattice mismatch, the X-ray diffraction pole figure shows a six-fold symmetrical pole of ZnO {103}, confirming that an epitaxial film was obtained.

Next, device characteristics of the above structure were examined. When the thickness of the ZnO thin film is H and the wavelength of the surface wave is λ, the TCF decreases as H / λ increases,
ppm / ° C, and 0 ppm when H / λ is about 0.1
/ ° C. When H / λ was larger than that, on the other hand, it became larger on the negative side. This phenomenon is considered to be an effect due to the cancellation between quartz and ZnO having different temperature coefficients of positive and negative as described above. On the other hand, k ² increased as H / λ increased, and was almost saturated when H / λ was about 0.3. The value at this time was about 10%. On the other hand, the sound speed monotonously decreased as H / λ increased. H /
When λ was 0.1, the sound speed was about 4600 m / s,
When H / λ was 0.3, it was about 4000 m / s.

In this device, in order to aim at a high frequency oscillator,
The standardized thickness H / lambda of preferentially ZnO thin films than the acoustic velocity k ² is 0.1 here. At this time, k ² is about 3%. With this value, you can use it for filters.

Next, the α-Al ₂ O of the non-piezoelectric material layer 21
₃ (001) Single crystal substrate surface and quartz single crystal substrate ZnO
The surface on which the thin film is not formed is bonded. The joining method is the same as in the first embodiment. Thus, an element having the structure shown in FIG. 2 can be manufactured. When trying to form a quartz thin film on α-Al ₂ O ₃ , only an amorphous film or a polycrystalline film can be formed.
With this method, a quartz single crystal can be formed on α-Al ₂ O ₃ . When the device characteristics of this structure were evaluated, TCF and k
² is almost the same as before joining α-Al ₂ O ₃ , but the sound velocity is 4600 by joining α-Al ₂ O _3.
m / s to 5500 m / s. This is advantageous for increasing the frequency in the GHz band. As described above, by configuring the device entirely with a single crystal and an epitaxial film, loss was smaller and the reproducibility of the device characteristics was better as compared with the case where a polycrystalline body, a polycrystalline film, and an amorphous film were used. .

As described above, in this embodiment, a surface acoustic wave device which can be sufficiently applied to a high frequency oscillator was obtained. this is,
It can also be applied to filters. The non-piezoelectric material, the piezoelectric material and the electrodes used here are α-Al ₂ O ₃ , ZnO, Al
-It is not limited to the Cu alloy. The plane orientation and cut angle of each layer are not limited to these. Furthermore, the thickness of each layer may be optimized according to the purpose and application. Also, the positions of the electrodes may be formed on the piezoelectric thin film.

(Embodiment 3) FIG. 3 is a view showing a sectional structure of a surface acoustic wave device according to Embodiment 3 of the present invention.

The element structure shown in FIG. 3 includes a layer 31 made of a non-piezoelectric material, a layer 32 made of a piezoelectric material, and a layer 3 made of quartz.
3, and a layer 32 made of a piezoelectric material and a layer 3 made of quartz
3 is formed of electrodes 34 formed between the electrodes. The basic configuration is the same as that of the first embodiment, except that the position of the electrode 34 is different. The specific material of each layer used here was the same as in Example 1.

In the case of this structure, it is difficult to form a high quality crystal layer 33. As described above, it is difficult to obtain an epitaxial film when forming a thin film. In addition, there is a problem that when forming by joining, it is not possible to join well due to unevenness due to electrodes. Also, if the electrodes are formed on the quartz layer, the benefits of a high-speed substrate made of a non-piezoelectric material cannot be obtained. Therefore, here, FIG.
The device of is manufactured.

FIG. 4 shows the manufacturing method along the steps. First, in FIG. 4A, a LiNbO ₃ thin film is formed as a piezoelectric material layer 32 on an α-Al ₂ O ₃ (001) substrate which is a non-piezoelectric material layer 31. Note that here, LiN
Although bO ₃ is formed, a LiNbO ₃ single crystal may be bonded. Subsequently, in (b), an Al-Cu alloy is deposited and further patterned. Next, in (c), a silicon dioxide film 35 made of the same constituent element as quartz is formed so as to hide the electrode 34. Finally, at (d), the surface of the silicon dioxide film 35 and the AT which has been polished on both sides of the quartz crystal layer 33 are formed.
Join the cut quartz single crystal. The joining method is the same as in the first embodiment. As a result, the quartz single crystal can be firmly joined even on the electrode 34. The element is completed by the above method.

The device characteristics showed the same tendency as in Example 1. Although the speed of sound is slightly inferior to Example 1, there is no problem in increasing the frequency. Further, the temperature control was easier than in Example 1. The optimum film thickness of each layer for setting the TCF at 0 ppm / ° C. is naturally different from that of the first embodiment. Optimization for this structure is required.

As described above, in this embodiment, a surface acoustic wave device which can be sufficiently applied to a high frequency oscillator was obtained. this is,
It can also be applied to filters. The non-piezoelectric material, the piezoelectric material, and the electrodes used here are α-Al ₂ O ₃ , LiNb
It is not limited to O ₃ or Al—Cu alloy. The plane orientation and cut angle of each layer are not limited to these.

(Embodiment 4) FIG. 5 is a view showing a sectional structure of a surface acoustic wave device according to Embodiment 4 of the present invention.

The element structure shown in FIG. 4 includes a layer 41 made of a non-piezoelectric material, a layer 42 made of quartz, and a layer 4 made of a piezoelectric material.
3, and an electrode 44 formed between a layer 41 made of a non-piezoelectric material and a layer 42 made of quartz. The basic configuration is the same as that of the second embodiment, except that the position of the electrode 44 is different. The specific material of each layer used here was the same as in Example 2.

Also in the case of this structure, it is difficult to form a high-quality crystal layer 42 for the same reason as in the third embodiment. Therefore, the element shown in FIG. 5 was manufactured in the same manner as in FIG. First, a piezoelectric thin film 43 of ZnO is formed on an AT-cut quartz crystal 42 polished on both sides. Next, α-Al ₂ O ₃
An electrode 44 was formed by forming an Al-Cu alloy thin film on the (001) substrate 41 and patterning it. Subsequently, the electrode 44 is formed on the α-Al ₂ O ₃ (001) substrate 41 on which the electrode 44 is formed.
A silicon dioxide film, which is the same as a constituent element of quartz, was formed so as to hide. Finally, the surface of the silicon dioxide film and the surface on which the piezoelectric thin film of quartz is not formed are joined. Thereby, the quartz single crystal can be firmly joined even on the electrode 44. The element is completed by the above method.

The device characteristics showed the same tendency as in Example 2. Compared to Example 2, the sound speed was faster. Also,
Temperature control was also possible. In addition, TCF is 0 ppm /
The optimum film thickness of each layer to be set to ° C. is naturally different from that of the second embodiment. Optimization for this structure is required.

As described above, according to this embodiment, a surface acoustic wave device which can be sufficiently applied to a high frequency oscillator was obtained. This can also be applied to filters. The non-piezoelectric material, the piezoelectric material, and the electrodes used here are α-Al ₂ O ₃ , ZnO,
It is not limited to the Al-Cu alloy. The plane orientation and cut angle of each layer are not limited to these.

[0046]

As described above, according to the present invention, a layer made of quartz, a layer made of a piezoelectric material other than quartz different from quartz, a layer made of a non-piezoelectric material, and an electrode are laminated,
The order of stacking the layers is arbitrary, and at least one of the layers is formed by bonding. The non-piezoelectric material has a Young's modulus of 3.5 × 10 ¹² dyne / cm ² or more and a density of 4 g / cm ^3. Each layer of a layer made of quartz, a layer made of a piezoelectric material other than quartz, and a layer made of a non-piezoelectric material is an epitaxial film or a single crystal, and the electrode is formed on at least one of the piezoelectric material layer and the layer made of quartz. By being formed in contact with each other, a high-performance surface acoustic wave element adaptable to high frequency can be provided.

According to the present invention, the bonding on the electrode is performed after the same material as the material to be bonded is previously deposited on the electrode by a film thickness equal to or larger than the electrode. By performing the following, a method for manufacturing a high-performance surface acoustic wave device can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a structure of a surface acoustic wave device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a structure of a surface acoustic wave device according to a second embodiment of the present invention.

FIG. 3 is a cross-sectional view illustrating a structure of a surface acoustic wave device according to a third embodiment of the present invention.

FIG. 4 is a cross-sectional view illustrating a method of manufacturing a surface acoustic wave device according to a third embodiment of the present invention along the steps.

FIG. 5 is a cross-sectional view illustrating a structure of a surface acoustic wave device according to a fourth embodiment of the present invention.

[Explanation of symbols]

 1, 21, 31, 41 Layer made of non-piezoelectric material 2, 23, 32, 43 Layer made of piezoelectric material 3, 22, 33, 42 Layer made of crystal 4, 24, 34, 44 Electrode 35 Silicon dioxide film

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Miyazawa 3-3-5 Yamato, Suwa-shi, Nagano F-term in Seiko Epson Corporation (reference) 5J097 AA13 AA28 BB01 BB11 DD28 EE08 FF02 HA02 HA03 KK09

Claims (5)

[Claims] 1. A device comprising: a layer made of quartz; a layer made of a piezoelectric material different from quartz; a layer made of a non-piezoelectric material; and an electrode. At least one of these layers is formed by bonding. Characteristic surface acoustic wave device. 2. The non-piezoelectric material has a Young's modulus of 3.5 × 1.
0¹²dyne / cm ^TwoAnd the density is 4 g / c
m^ThreeThe surface bullet according to claim 1, characterized in that:
Sex wave element. 3. The method according to claim 1, wherein each of the layer made of quartz, the layer made of a piezoelectric material different from quartz, and the layer made of a non-piezoelectric material is made of an epitaxial film or a single crystal.
The surface acoustic wave device as described in the above. 4. The surface acoustic wave device according to claim 1, wherein the electrode is formed in contact with at least one of the piezoelectric material layer and the layer made of quartz. 5. A device comprising a layer made of quartz, a layer made of a piezoelectric material different from quartz, a layer made of a non-piezoelectric material, and an electrode, and at least one of these layers is a surface acoustic wave formed by bonding. A method of manufacturing an element, wherein the bonding of another member to the electrode is performed after previously depositing the same material as the material to be bonded on the electrode by a thickness equal to or greater than the electrode, and the bonding temperature is equal to or lower than the phase transition temperature of quartz. A method for manufacturing a surface acoustic wave device.