Piezoelectric film integrated device, method for manufacturing the same, and acoustic vibration sensor

Abstract

To improve the performance of a piezoelectric film integrated device by providing two or more types of monocrystalline piezoelectric films on the same substrate.SOLUTION: A piezoelectric film integrated device includes: a substrate (33); a first electrode (34a) provided on the substrate (33); a second electrode (34b) provided on the substrate (33); a monocrystalline PZT film, as a first monocrystalline piezoelectric film (15), provided on the first electrode (34a); a monocrystalline AlN film, as a second monocrystalline piezoelectric film (25) having a crystalline structure different from that of the first monocrystalline piezoelectric film (15), provided on the second electrode (34b); a third electrode (16) provided on the first monocrystalline piezoelectric film (15); and a fourth electrode (26) provided on the second monocrystalline piezoelectric film (25).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a piezoelectric film integrated device, a method for manufacturing the same, and an acoustic vibration sensor.

Background Art

[0002] Conventionally, there has been disclosed a device that forms different types of polycrystalline piezoelectric films on the same substrate to constitute an ultrasonic sensor (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in conventional devices, when a plurality of polycrystalline piezoelectric films are arranged on the same substrate, a high-performance piezoelectric film integrated device cannot be obtained.

[0005] An object of the present disclosure is to provide a high-performance piezoelectric film integrated device provided with two or more types of single-crystalline piezoelectric films on the same substrate, a method for manufacturing the same, and an acoustic vibration sensor having the piezoelectric film integrated device.

Means for Solving the Problems

[0006] The piezoelectric film integrated device of the present disclosure includes a substrate, a first electrode provided on the substrate, a second electrode provided on the substrate, a first single-crystalline piezoelectric film provided on the first electrode, a second single-crystalline piezoelectric film provided on the second electrode and having a crystal structure different from that of the first single-crystalline piezoelectric film, a third electrode provided on the first single-crystalline piezoelectric film, and a fourth electrode provided on the second single-crystalline piezoelectric film. Furthermore, at least one of the first single-crystal piezoelectric film and the second single-crystal piezoelectric film is an epitaxially grown film that is grown on a growth substrate different from the substrate. It is characterized by the above.

Effects of the Invention

[0007] According to this disclosure, the performance of piezoelectric film integrated devices and acoustic vibration sensors can be improved by providing two or more types of single-crystal piezoelectric films on the same substrate. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic side view showing the structure of the piezoelectric film integrated device according to Embodiment 1. [Figure 2] Figure 1 is a schematic top view showing the structure of the piezoelectric film integrated device. [Figure 3] Figure 2 is a cross-sectional view of the piezoelectric film integrated device cut along the line S3-S3. [Figure 4] Figure 1 is a schematic bottom view showing the structure of the piezoelectric film integrated device. [Figure 5] This is a schematic cross-sectional view showing the structure of an epitaxially grown film containing a single-crystal piezoelectric film, specifically a single-crystal PZT film. [Figure 6] Figure 5 shows the crystal structure of a single-crystal PZT film. [Figure 7] Figure 5 shows a schematic diagram of the crystal structure of the epitaxially grown film. [Figure 8] This is a schematic cross-sectional view showing the structure of an epitaxially grown film containing a single-crystal AlN film, which is a single-crystal piezoelectric film. [Figure 9] (A) is a schematic diagram showing the (111) plane of the single-crystal SRO film, single-crystal Pt, and single-crystal ZrO2 crystals in Figure 8, and (B) is a diagram showing the lattice constant of the single-crystal SRO crystal. [Figure 10] (A) is a schematic diagram showing the crystal structure of the single-crystal AlN film in Figure 8, and (B) is a diagram showing the lattice constants of the single-crystal AlN. [Figure 11] Figure 1 is a flowchart showing the manufacturing method of a piezoelectric film integrated device. [Figure 12] (A) and (B) are schematic cross-sectional and top views showing the structures of the first and second electrodes in step ST102 of Figure 11. [Figure 13] (A) and (B) are top views and cross-sectional views schematically showing the structure of the first epitaxial growth film in step ST103 of FIG. 11. [Figure 14] (A) and (B) are top views and cross-sectional views schematically showing the structure of the first epitaxial growth film in step ST104 of FIG. 11. [Figure 15] It is a cross-sectional view schematically showing the holding process of the first epitaxial growth film in step ST105 of FIG. 11. [Figure 16] It is a cross-sectional view schematically showing the etching process of the sacrificial layer in step ST105 of FIG. 11. [Figure 17] (A) and (B) are top views and cross-sectional views schematically showing the structure of the second epitaxial growth film in step ST106 of FIG. 11. [Figure 18] (A) and (B) are top views and cross-sectional views schematically showing the structure of the second epitaxial growth film in step ST107 of FIG. 11. [Figure 19] It is a cross-sectional view schematically showing the holding process of the second epitaxial growth film in step ST108 of FIG. 11. [Figure 20] It is a cross-sectional view schematically showing the etching process of the sacrificial layer in step ST108 of FIG. 11. [Figure 21] It is a cross-sectional view schematically showing the bonding process of the first epitaxial growth film and the second epitaxial growth film in step ST109 of FIG. 11. [Figure 22] It is a cross-sectional view schematically showing the structure of the piezoelectric film integrated device in step ST110 of FIG. 11. [Figure 23] It is a diagram showing the crystal c-axis of the single crystal PZT film which is the first single crystal piezoelectric film and the crystal c-axis of the single crystal AlN film which is the second single crystal piezoelectric film. [Figure 24] It is a diagram schematically showing the configuration of an acoustic vibration sensor using the semiconductor integrated device according to Embodiment 1. [Figure 25] It is a diagram showing the operating principle of the acoustic vibration sensor. [Figure 26] It is a side view schematically showing the structure of a piezoelectric film integrated device according to a modification of Embodiment 1. [Figure 27] It is a top view schematically showing the structure of the piezoelectric film integrated device of FIG. 26. [Figure 28] It is a cross-sectional view of the piezoelectric film integrated device of FIG. 27 cut along line S28 - S28. [Figure 29] It is a bottom view schematically showing the structure of the piezoelectric film integrated device of FIG. 26. [Figure 30] It is a side view schematically showing the structure of a piezoelectric film integrated device according to Embodiment 2. [Figure 31] It is a top view schematically showing the structure of the piezoelectric film integrated device of FIG. 30. [Figure 32] It is a cross-sectional view of the piezoelectric film integrated device of FIG. 31 cut along line S32 - S32. [Figure 33] It is a flowchart showing the manufacturing method of the piezoelectric film integrated device of FIG. 30. [Figure 34] It is a cross-sectional view schematically showing the structure of the first epitaxial growth film in step ST203 of FIG. 33. [Figure 35] It is a cross-sectional view schematically showing the structure of the first epitaxial growth film (individual piece) in step ST204 of FIG. 33. [Figure 36] It is a cross-sectional view schematically showing the structures of the first epitaxial growth film (individual piece) and the second epitaxial growth film (individual piece) in step ST208 of FIG. 33. [Figure 37] It is a cross-sectional view schematically showing the structure of the piezoelectric film integrated device in step ST209 of FIG. 33. [Figure 38] It is a side view schematically showing the structure of a piezoelectric film integrated device according to Embodiment 3. [Figure 39] It is a top view schematically showing the structure of the piezoelectric film integrated device of FIG. 38. [Figure 40] It is a cross-sectional view of the piezoelectric film integrated device of FIG. 39 cut along line S40 - S40. [Figure 41]Figure 38 is a flowchart showing the manufacturing method of a piezoelectric film integrated device. [Figure 42] Figure 41 is a schematic cross-sectional view showing the structure of the second epitaxial growth film in step ST303. [Figure 43] Figure 41 is a schematic cross-sectional view showing the structure of the second epitaxial growth membrane (piece) in step ST304. [Figure 44] Figure 41 is a schematic cross-sectional view showing the structures of the first epitaxial growth membrane (piece) and the second epitaxial growth membrane (piece) in step ST308. [Figure 45] Figure 41 is a schematic cross-sectional view showing the structure of the piezoelectric film integrated device in step ST309. [Figure 46] This is a schematic cross-sectional view showing the structure of an epitaxially grown film containing a single-crystal PZT film. [Figure 47] This is a schematic cross-sectional view showing the structure of an epitaxially grown film containing a single-crystal AlN film. [Figure 48] This is a schematic cross-sectional view showing the structure of a piezoelectric film integrated device according to a modified example 1 of Embodiment 1. [Figure 49] Figure 48 is a schematic top view showing the structure of the piezoelectric film integrated device. [Modes for carrying out the invention]

[0009] Below, a piezoelectric film integrated device, a method for manufacturing the same, and an acoustic vibration sensor according to an embodiment will be described with reference to the drawings. The following embodiments are merely examples, and various modifications are possible within the scope of this disclosure. In this application, a piezoelectric film integrated device is a device having two or more single-crystal piezoelectric films on the same substrate. In this application, an acoustic vibration sensor is a sensor that outputs an acoustic vibration wave and detects the state of an object to be detected (e.g., distance, shape, movement, etc.) by detecting the reflected wave of the acoustic vibration wave. An acoustic vibration sensor is also called an "ultrasonic sensor." Generally, and also in this application, an acoustic vibration wave consists of at least one of a sound wave and an ultrasonic wave. That is, an acoustic vibration wave consists of a sound wave, or an ultrasonic wave, or both a sound wave and an ultrasonic wave.

[0010] (1) Embodiment 1 《1-1》Structure of piezoelectric film integrated device 100 Figure 1 is a schematic side view showing the structure of the piezoelectric film integrated device 100 according to Embodiment 1. Figure 2 is a schematic top view showing the structure of the piezoelectric film integrated device 100. Figure 3 is a cross-sectional view of the piezoelectric film integrated device 100 in Figure 2, cut along the line S3-S3. Figure 4 is a schematic bottom view showing the structure of the piezoelectric film integrated device 100.

[0011] The piezoelectric film integrated device 100 includes an SOI substrate 33 as a substrate, a platinum (Pt) film 34a as a first electrode provided on the SOI substrate 33, and a Pt film 34b as a second electrode provided on the SOI substrate 33. As shown in Figure 2, the Pt films 34a and 34b are connected to the connector 40 through a wiring layer formed on the SOI substrate 33. SOI stands for Silicon On Insulator. Furthermore, a drive circuit for driving the piezoelectric film integrated device 100 to generate acoustic vibration waves and a processing circuit for processing using the detection signal of the acoustic vibration waves may be formed within the SOI substrate 33.

[0012] The piezoelectric film integrated device 100 has a single-crystal PZT film 15 as a first single-crystal piezoelectric film provided on a Pt film 34a, and a single-crystal AlN film 25 as a second single-crystal piezoelectric film provided on a Pt film 34b and having a different crystal structure from the first single-crystal piezoelectric film. PZT is lead zirconate titanate. AlN is aluminum nitride. As the first single-crystal piezoelectric film, a piezoelectric film made of another single-crystal material such as a single-crystal potassium sodium niobate (single-crystal KNN) film or a single-crystal barium titanate (single-crystal BaTiO3) film may be used instead of the single-crystal PZT film 15. As the second single-crystal piezoelectric film, a piezoelectric film made of another single-crystal material such as a single-crystal lithium tantalate (single-crystal LiTaO3) film or a single-crystal lithium niobate (single-crystal LiNbO3) film may be used instead of the single-crystal AlN film 25. The first single-crystal piezoelectric film is a piezoelectric material that generates acoustic vibration waves, and it is desirable that it is a piezoelectric material that can obtain a vibration amplitude larger than that of the second single-crystal piezoelectric film. The second single-crystal piezoelectric film is a piezoelectric material that detects acoustic vibration waves (or their reflected waves), and it is desirable that it is a piezoelectric material with a detection sensitivity higher than that of the first single-crystal piezoelectric film.

[0013] Furthermore, the piezoelectric film integrated device 100 has a Pt film 16 as a third electrode provided on a single crystal PZT film 15, and a Pt film 26 as a fourth electrode provided on a single crystal AlN film 25. In addition, the piezoelectric film integrated device 100 has insulating films 35a and 35b, and wiring films 36a and 36b formed thereon.

[0014] The SOI substrate 33 has a Si substrate 30, a silicon oxide (SiO2) portion 31 as an insulating film, and a single-crystal silicon (single-crystal Si) portion 32. Holes 71 and 72 are formed by etching the Si substrate 30 in the lower regions of the single-crystal PZT film 15 and single-crystal AlN film 25 of the SiO2 portion 31 and the single-crystal silicon (single-crystal Si) portion 32 (i.e., the regions overlapping the piezoelectric film), and the SiO2 portion 31 and single-crystal silicon (single-crystal Si) portion 32 located in the regions where holes 71 and 72 (cavities) are formed function as a diaphragm. Furthermore, by forming the silicon oxide (SiO2) portion 31, which is a different material from the Si substrate 30, and giving it the function of an etching stop layer, it is possible to prevent variations in the thickness of the diaphragm due to the effects of etching. As a substrate, a substrate made of other materials such as a glass substrate or an organic film substrate may be used instead of the SOI substrate 33. Holes 71 and 72 are formed in the Si substrate 30 of the SOI substrate 33 to expose the SiO2 portion 31. Holes 71 and 72 are formed in a circular shape, corresponding to the shapes of the single-crystal PZT film 15 and the single-crystal AlN film 25, respectively. Acoustic vibration waves generated in the single-crystal PZT film 15 are output from hole 71, and the single-crystal AlN film 25 detects the reflected acoustic vibration waves through hole 72.

[0015] The single-crystal PZT film 15 has a (001) plane, which is a crystal plane parallel to the surface of the Pt film 34a, and is an epitaxially grown film attached to the surface of the Pt film 34a. The single-crystal AlN film 25 has a (0001) plane, which is a crystal plane parallel to the surface of the Pt film 34b, and is an epitaxially grown film attached to the surface of the Pt film 34b. The thickness of the single-crystal PZT film 15 is generally in the range of 10 nm to 10 μm, preferably in the range of 100 nm to 5 μm. The thickness of the single-crystal AlN film 25 is generally in the range of 10 nm to 10 μm, preferably in the range of 100 nm to 2 μm. The Pt film 34a and the Pt film 34b are formed on the upper surface of the same SOI substrate 33. The surfaces of the Pt film 34a and the Pt film 34b are parallel to each other. The surface (top surface) of the Pt film 34a and the (001) crystal plane of the single-crystal PZT film 15 are joined by intermolecular forces. The surface (top surface) of the Pt film 34b and the (0001) crystal plane of the single-crystal AlN film 25 are joined by intermolecular forces. Adhesives are not required for these joining processes. To ensure good joining by intermolecular forces, it is desirable that the surface roughness of the Pt film 34a and Pt film 34b be 10 nm or less. For this reason, the surfaces of the Pt film 34a and Pt film 34b may be smoothed.

[0016] Furthermore, the crystal c-axis direction of the single-crystal PZT film 15 and the crystal c-axis direction of the single-crystal AlN film 25 are parallel. This will be explained later using Figure 23.

[0017] 《1-2》Structure of single-crystal PZT film Figure 5 is a schematic cross-sectional view showing the structure of an epitaxially grown film containing a single-crystal PZT film 15. Figure 6 is a diagram showing the crystal structure of the single-crystal PZT film 15 in Figure 5. Figure 7 is a schematic diagram showing the crystal structure of the epitaxially grown film in Figure 5. Note that in Figure 7, the vertical dimensions are significantly reduced compared to the horizontal dimensions.

[0018] The epitaxially grown film in Figure 5 is formed on a growth substrate 11, which is a single-crystal Si substrate. The epitaxially grown film in Figure 5 has a structure in which a single-crystal zirconium oxide (ZrO2) film 12, a single-crystal Pt film 13, a single-crystal SRO film 14, a single-crystal PZT film 15, and a single-crystal Pt film 16 are stacked in this order. The growth substrate 11 is an example of a substrate whose upper surface is a (100) plane. The ZrO2 film 12 is an example of an oriented film having a cubic crystal structure and whose upper surface is a (100) plane. The Pt film 13 is an example of a conductive film having a cubic crystal structure and whose upper surface is a (100) plane. The SRO film 14 is a SrRuO3 film (strontium ruthenate film) and is an example of an oriented film. The single-crystal PZT film 15 is an example of a single-crystal piezoelectric film for vibration output. When the single-crystal PZT film 15 contains a composite oxide having a perovskite-type structure, the single-crystal PZT film 15 can be epitaxially grown on the growth substrate 11 with a tetragonal orientation of (001). Furthermore, a Pt film 16 having a cubic crystal structure and being (100) oriented is epitaxially grown on the single-crystal PZT film 15.

[0019] "The ZrO2 film 12 is (100) oriented" means that the (100) plane of the ZrO2 film 12, which has a cubic crystal structure, is formed along the (100) plane of the growth substrate 11, that is, it is parallel to the (100) plane of the growth substrate 11. Furthermore, "parallel" includes the case where the angle between the top surface of the growth substrate 11 and the (100) plane of the ZrO2 film 12 is 20° or less. The meaning of "orientation" is similar among other films.

[0020] Table 1 shows the lattice constants of the single crystal Si in the growth substrate 11, the ZrO2 in the ZrO2 film 12, the Pt in the Pt film 13, the SRO in the SRO film 14, and the single crystal PZT in the single crystal PZT film 15.

[0021] [Table 1]

[0022] The lattice constant of Si is 0.543 nm, and the lattice constant of ZrO2 is 0.511 nm. The mismatch between the lattice constant of ZrO2 and that of Si is small, at 6.1%, indicating good compatibility between the lattice constant of ZrO2 and that of Si. Therefore, as shown in the schematic diagram Figure 7, the oriented ZrO2 film 12 can be epitaxially grown on the main plane of the growth substrate 11, which consists of the (100) plane. Consequently, the ZrO2 film 12 can be (100) oriented on the (100) plane of the growth substrate 11 with a cubic crystal structure, thereby improving the crystallinity of the ZrO2 film 12.

[0023] If the ZrO2 film 12 has a cubic crystal structure and is a (100) oriented zirconium oxide film, then the ZrO2 film 12 is along the upper surface, which is the main surface of the growth substrate 11. <100> The direction is aligned with the upper surface of the growth substrate 11. <100> It is oriented so as to be parallel to the direction.

[0024] Furthermore, along the upper surface of the growth substrate 11, the ZrO2 film 12 <100> The direction is aligned with the upper surface of the growth substrate 11. <100> Parallel to the direction means that the ZrO2 film 12 <100> The direction is aligned with the upper surface of the substrate 11. <100> Not only when perfectly parallel to the direction, but also the zirconium oxide film 12 <100> Direction and along the upper surface of the growth substrate 11 <100> This includes cases where the angle with respect to the direction is 20° or less. Furthermore, the same applies to the in-plane orientation of other layers of the film, not just the ZrO2 film 12.

[0025] On the other hand, as shown in Table 1, the lattice constant of ZrO2 is 0.511 nm, and the lattice constant of Pt is 0.392 nm. However, when Pt is rotated 45° in the plane, the length of the diagonal becomes 0.554 nm, and the mismatch between the length of this diagonal and the lattice constant of ZrO2 is small, at 8.1%. For this reason, the Pt film 13 can be epitaxially grown on the (100) plane of the ZrO2 film 12.

[0026] Furthermore, as shown in Table 1, the lattice constant of Pt is 0.392 nm, and the lattice constant of SRO is 0.390-0.393 nm, and the mismatch between the lattice constant of Pt and the lattice constant of single crystal PZT is small, less than 0.5%. Therefore, the lattice constant of SRO matches well with that of Pt, and as shown in Figure 7, the SRO film 14 can be epitaxially grown on the (100) plane of the Pt film 13. Consequently, the SRO film 14 can be (100) oriented in a pseudocubic crystal representation on the (100) plane of the Pt film 13, and the crystallinity of the SRO film 14 can be improved.

[0027] When the single-crystal PZT film 15 has a tetragonal crystal structure and includes a (001) oriented PZT film, the lead zirconate titanate film is along the upper surface of the growth substrate 11 of the lead zirconate titanate film. <100> The direction is along the upper surface of the growth substrate 11. <100> It is oriented so as to be parallel to the direction.

[0028] A Pt film 16 is formed as an electrode by epitaxial growth of a (100) oriented PZT film 15 that is oriented (001). Since the electrode film on the single crystal PZT film 15 is the uppermost layer, it may be formed by other manufacturing methods.

[0029] 《1-3》Structure of a single-crystal AlN film Figure 8 is a schematic cross-sectional view showing the structure of an epitaxially grown film including a single-crystal piezoelectric film, a single-crystal AlN film 25. Figure 9(A) is a schematic diagram showing the (111) plane of the crystals of a single-crystal SRO film, a single-crystal Pt film, and a single-crystal ZrO2 film, and Figure 9(B) is a diagram showing the lattice constant of the crystal of the single-crystal SRO. Figure 10(A) is a schematic diagram showing the crystal structure of the single-crystal AlN film 25, and Figure 10(B) is a diagram showing the lattice constant of the crystal of the single-crystal AlN film 25.

[0030] The epitaxially grown film in Figure 8 is formed on a growth substrate 21, which is, for example, a single-crystal Si substrate. The epitaxially grown film has a structure in which a ZrO2 film 22, a Pt film 23, an SRO film 24, a single-crystal AlN film 25, and a Pt film 26 are stacked in this order. The growth substrate 21 is an example of a substrate whose upper surface is a (111) plane. The ZrO2 film 22 is an example of an oriented film having a cubic crystal structure and whose upper surface is a (111) plane. The Pt film 23 is an example of a conductive film having a cubic crystal structure and whose upper surface is a (111) plane. The SRO film 24 is a SrRuO3 film. The single-crystal AlN film 25 is an example of a single-crystal piezoelectric film for vibration detection (i.e., for input). The Pt film 26 is an example of an upper electrode. Figure 9(A) shows the top-down view of the (111) plane of the SRO cubic crystal. Figure 10(A) shows the top-down view of the (0001) plane, which is a crystal plane of the AlN hexagonal crystal.

[0031] When the single-crystal AlN film 25 is composed of hexagonal aluminum nitride, the single-crystal AlN film 25 can be epitaxially grown on the growth substrate 21 with a (0001) orientation in hexagonal representation. Furthermore, a Pt film 26 having a cubic crystal structure and oriented (100) can be epitaxially grown on the single-crystal AlN film 25.

[0032] "The ZrO2 film 22 is (111) oriented" means that the (111) plane of the ZrO2 film 22, which has a cubic crystal structure, is aligned with the (111) plane of the growth substrate 21, that is, parallel to the (111) plane of the growth substrate 21. Furthermore, "parallel" includes cases where the angle between the (111) plane of the ZrO2 film 22 and the main plane of the growth substrate 21 is 20° or less. The same applies to orientation between other layers.

[0033] Table 2 shows the lattice constants for Si, ZrO2, Pt, SRO, and single-crystal AlN.

[0034] [Table 2]

[0035] The lattice constant of Si is 0.543 nm, and the lattice constant of ZrO2 is 0.511 nm. The mismatch between the lattice constant of ZrO2 and that of Si is small, at 6.1%, indicating good lattice consistency between ZrO2 and Si. Therefore, the ZrO2 film 22 can be epitaxially grown on the main plane of the growth substrate 21, which consists of (111) planes. Consequently, the ZrO2 film 22 can be (111) oriented with a cubic crystal structure on the (111) plane of the growth substrate 21, thereby improving the crystallinity of the ZrO2 film 22. Figure 9(A) shows the (111) plane of a cubic crystal.

[0036] If the oriented film, ZrO2 film 22, has a cubic crystal structure and is a (111) oriented zirconium oxide film, then the ZrO2 film 12 is aligned along the upper surface, which is the main surface of the growth substrate 21. <111> The direction is along the upper surface of the growth substrate 21. <111> It is oriented so as to be parallel to the direction.

[0037] Furthermore, along the upper surface of the growth substrate 21, the ZrO2 film 22 <111> The direction is along the upper surface of the growth substrate 21. <111> Parallel to the direction means that the ZrO2 film 22 <111> The direction is aligned with the upper surface of the growth substrate 21. <111> Not only when perfectly parallel to the direction, but also the ZrO2 film 22 <111> Direction and along the upper surface of the growth substrate 21 <111> This includes cases where the angle with respect to the direction is 20° or less. The same applies to the orientation between layers of film.

[0038] On the other hand, the lattice constant of ZrO2 is 0.511 nm, and the lattice constant of Pt is 0.392 nm. However, when Pt is rotated 45° in the plane, the length of the diagonal becomes 0.554 nm. The mismatch between the length of this diagonal and the lattice constant of ZrO2 is small, at 8.1%, so the Pt film 23 can be epitaxially grown on the (111) plane of the ZrO2 film 22.

[0039] Furthermore, the lattice constant of Pt is 0.392 nm, and the lattice constant of SRO is 0.390 to 0.393 nm, indicating good compatibility between the lattice constant of SRO and that of Pt. Therefore, as shown in Figures 9(A) and (B)5, the SRO film 24 can be epitaxially grown on the (111) plane of the Pt film 23. Consequently, the SRO film 24 can be (111) oriented in a pseudocubic crystal representation on the (111) plane of the Pt film 23, thereby improving the crystallinity of the SRO film 24. The diagonal length of the (111) plane of the SRO film is 0.552 to 0.556 nm, and as shown in Figure 8, the mismatch with the width of the AlN hexagonal crystal (0.539 nm) is small at 2.8%, allowing the single-crystal AlN film 25 to be epitaxially grown on the (111) plane of the SRO film 24 in a (0001) orientation.

[0040] When the single-crystal AlN film 25 has a hexagonal crystal structure and includes an aluminum nitride film oriented to (0001), along the upper surface of the growth substrate 21 of the single-crystal AlN film 25 <111> The direction is the upper surface of the growth substrate 21 <111> The film is oriented parallel to the direction. Figures 10(A) and (B) show the (0001) plane of the hexagonal crystal. A Pt film 26 is then formed as an electrode by epitaxial growth in the (111) orientation on the (0001) oriented single crystal AlN film 25. Since the electrode film on the single crystal AlN film 25 is the uppermost layer, it may be formed by other manufacturing methods.

[0041] 《1-4》Manufacturing method A method for manufacturing a piezoelectric film integrated device 100 will be described using a single-crystal PZT film 15 deposited on a growth substrate 11 whose upper surface is the (100) plane of single-crystal Si, and a single-crystal AlN film 25 deposited on a growth substrate 21 whose upper surface is the (111) plane of single-crystal Si.

[0042] Figure 11 is a flowchart showing the manufacturing method of the piezoelectric film integrated device 100. Figures 12(A) and (B) show step ST102 of Figure 11. Figures 13(A) and (B) show step ST103 of Figure 11, Figures 14(A) and (B) show step ST104 of Figure 11, and Figures 15 and 16 show step ST105 of Figure 11. Figures 17(A) and (B) show step ST106 of Figure 11, Figures 18(A) and (B) show step ST107 of Figure 11, and Figures 19 and 20 show step ST108 of Figure 11. Figure 21 shows step ST109 of Figure 11, and Figure 22 shows step ST110 of Figure 11.

[0043] First, a wiring layer is formed on the SOI substrate 33, which is the device substrate (step ST101). Next, as shown in Figures 12(A) and (B), a Pt film 34a as the first electrode and a Pt film 34b as the second electrode are formed on the main surface of the SOI substrate 33.

[0044] Furthermore, as shown in Figures 13(A) and (B), an SRO film 14, a single-crystal PZT film 15, and a Pt film 16 are epitaxially grown on a growth substrate 11, which is the first growth substrate (step ST103), and as shown in Figures 14(A) and (B), the shape of the single-crystal PZT film 15 is made circular by etching (step ST104). Then, as shown in Figure 15, individual pieces consisting of the single-crystal PZT film 15 and the Pt film 16 are held by a stamp 80 as a holding member, and as shown in Figure 16, the sacrificial layer, the SRO film 14, is etched to peel off the individual pieces, and they are moved onto the SOI substrate 33, which is the device substrate (step ST105).

[0045] Furthermore, as shown in Figures 17(A) and (B), an SRO film 24, a single-crystal AlN film 25, and a Pt film 26 are epitaxially grown on a growth substrate 21, which is a second growth substrate (step ST106), and as shown in Figures 18(A) and (B), the shape of the single-crystal AlN film 25 is made circular by etching (step ST107). Then, as shown in Figure 19, individual pieces consisting of the single-crystal AlN film 25 and the Pt film 26 are held by a stamp 80 as a holding member, and as shown in Figure 20, the sacrificial layer, the SRO film 24, is etched to peel off the individual pieces, which are then moved onto the SOI substrate 33 (step ST108).

[0046] Next, as shown in Figure 21, a piece consisting of a single-crystal PZT film 15 and a Pt film 16 (the first epitaxially grown film) is attached to the first electrode, a Pt film 34a, and a piece consisting of a single-crystal AlN film 25 and a Pt film 26 (the second epitaxially grown film) is attached to the second electrode, a Pt film 34b (step ST109). Next, an insulating film 35a and a wiring film 36a are formed on the single-crystal PZT film 15 and the Pt film 16, and an insulating film 35b and a wiring film 36b are formed on the single-crystal AlN film 25 and the Pt film 26.

[0047] Figure 23 shows the crystal c-axis of the first single-crystal piezoelectric film, a single-crystal PZT film 15, and the second single-crystal piezoelectric film, a single-crystal AlN film 25. As shown in Figure 23, when attaching them, the efficiency of piezoelectric vibration driving of the single-crystal PZT film 15 and piezoelectric vibration reception of the single-crystal AlN film 25 is maximized by arranging the hexagonal crystal structure of AlN and the cubic crystal structure of PZT so that their c-axises are parallel, as shown in the figure.

[0048] After bonding, insulating films 35a and 35b are formed on the SOI substrate 33, and wiring films 36a and 36b are formed on each electrode and connected to a predetermined wiring pattern.

[0049] As shown in Figure 24, the back side of the piezoelectric element is thinned by etching the SOI substrate 33 down to the SiO2 portion 31, thereby creating a diaphragm. The thickness of the diaphragm can be adjusted to the desired thickness by controlling the thickness of each layer of the SOI substrate 33.

[0050] 《1-5》 Acoustic vibration sensor Figure 24 schematically shows the configuration of an acoustic vibration sensor using a semiconductor integrated device according to Embodiment 1. Figure 25 shows the operating principle of the acoustic vibration sensor. The upper and lower electrodes of the single crystal PZT film 15 are connected to the drive-receiving circuit 41, and by applying an AC bias of a frequency in the audible range or higher than the audible range to the electrodes of the single crystal PZT film 15, the single crystal PZT film 15 vibrates in the thickness direction, and the SiO2 part 31 vibrates similarly. Accordingly, acoustic vibration waves are radiated, and the reflected waves bounced off the object to be detected 90 cause the diaphragm of the SOI substrate 33 to which the single crystal AlN film 25 is attached to vibrate. The charge excited in the single crystal AlN film 25 by the vibration is amplified by the drive-receiving circuit 41, and the control circuit 42 calculates the distance to the object to be detected 90 based on the time difference Δt of receiving the reflected wave. The control circuit 42 and the drive-receiving circuit 41 are composed of electrical circuits or information processing devices.

[0051] 《1-6》 Variant Figure 26 is a schematic side view showing the structure of a piezoelectric film integrated device 100a according to a modified example of Embodiment 1. Figure 27 is a schematic top view showing the structure of the piezoelectric film integrated device 100a. Figure 28 is a cross-sectional view of the piezoelectric film integrated device 100a in Figure 27, cut along the line S28-S28. Figure 29 is a schematic bottom view showing the structure of the piezoelectric film integrated device 100a. When etching the SOI substrate 33 down to the SiO2 portion 31, the shapes of the holes 73 and 74 may be other shapes such as squares. It is desirable that the shapes of the holes 73 and 74 correspond to the planar shape of the piezoelectric element.

[0052] Effect 1-7 As explained above, single-crystal PZT film 15 and single-crystal AlN film 25, which are difficult to epitaxially grow on the same SOI substrate 33 due to their different lattice constants and crystal structures, can be epitaxially grown on separate growth substrates, peeled off from the growth substrates, and attached to a common SOI substrate 33 to create a high-performance piezoelectric film integrated device 100.

[0053] Furthermore, since the single-crystal PZT film 15 has a higher piezoelectric constant than the polycrystalline PZT film, the amplitude of vibration can be easily increased.

[0054] Furthermore, since the single-crystal AlN film 25 has a lower dielectric constant than the polycrystalline AlN film, it can improve the sensitivity to vibration reception.

[0055] Furthermore, conventionally, forming dissimilar piezoelectric films involved complex processes such as covering one piezoelectric film with a protective layer and then removing the protective layer after forming the other piezoelectric film. Moreover, the heat applied during each process left residual stress and strain in the piezoelectric film, leading to a decrease in sensor efficiency. In the manufacturing method of Embodiment 1, since an epitaxial growth film, which is a single-crystal piezoelectric film, is attached, it is possible to construct a piezoelectric film integrated device and an acoustic vibration sensor without residual stress and strain.

[0056] (2) Embodiment 2 《2-1》Structure Figure 30 is a schematic side view showing the structure of the piezoelectric film integrated device 200. Figure 31 is a schematic top view showing the structure of the piezoelectric film integrated device 200. Figure 32 is a cross-sectional view of the piezoelectric film integrated device 200 of Figure 31, cut along the line S32-S32.

[0057] In Embodiment 1, both the single-crystal PZT film 15 and the single-crystal AlN film 25 were grown on growth substrates 11 and 21, respectively, and then attached to the Pt film on the SOI substrate 33. In Embodiment 2, however, the single-crystal PZT film 15 is epitaxially grown on the SOI substrate 50. The SOI substrate 50 has a (100) plane on its upper surface. Therefore, it is possible to epitaxially grow a single crystal of the single-crystal PZT film 15 using the same process as in Embodiment 1.

[0058] 《2-2》Manufacturing method Figure 33 is a flowchart showing the manufacturing method of the piezoelectric film integrated device 200. Figure 34 shows steps ST201 and ST202 of Figure 33, and Figure 35 shows step ST203 of Figure 33. Figure 36 shows step ST208 of Figure 33, and Figure 37 shows step ST209 of Figure 33.

[0059] First, as shown in Figure 34, a ZrO2 film 12 and a Pt film 13 as an electrode layer are formed on the main surface of the SOI substrate 50, which is the device substrate (step ST201). Next, as shown in Figure 34, an SRO film 14, a single-crystal PZT film 15, and a Pt film 16 are epitaxially grown on the Pt film 13 to form an epitaxially grown film consisting of the SRO film 14, the single-crystal PZT film 15, and the Pt film 16 (step ST202). Next, as shown in Figure 35, the shape of the epitaxially grown film including the single-crystal PZT film 15 is etched to a desired shape (for example, a circular shape) (step ST203). Next, the Pt film 13 as an electrode layer is etched to form a Pt film 34a as a first electrode and a Pt film 34b as a second electrode.

[0060] Next, individual pieces consisting of a single-crystal AlN film 25 and a Pt film 26 are held by a stamp 80 as a holding member, and as shown in Figure 36, the sacrificial layer, the SRO film 24, is etched to peel off the individual pieces, which are then moved onto the SOI substrate 50, which is the device substrate, and attached (steps ST205 to ST208). Here, the single-crystal AlN film 25 described in Embodiment 1 is formed separately and attached to the electrode. When attaching, the crystal orientation of the single-crystal PZT film 15 is confirmed by inspection, etc., and the crystal orientation of the single-crystal PZT film 15 and the crystal orientation of the single-crystal AlN film 25 are aligned as shown in Figure 23. The orientation of the single-crystal PZT film 15 is fixed on the SOI substrate 50, so the attachment angle of the single-crystal AlN film 25 is adjusted. Alternatively, after confirming the crystal orientation during the etching process shown in Figure 35, the piezoelectric film may be formed by masking so that it is in the same direction as in Embodiment 1. As shown in Figure 37, an insulating film 35a and a wiring film (lead-out wiring) 36a are formed on the single crystal PZT film 15 and the Pt film 16, and an insulating film 35b and a wiring film (lead-out wiring) 36b are formed on the single crystal AlN film 25 and the Pt film 26.

[0061] Subsequently, the SOI substrate 50 is etched in the same manner as in Embodiment 1 to manufacture the piezoelectric film integrated device 200 shown in Figures 30 to 32.

[0062] 《2-3》Effect In Embodiment 2, by attaching an epitaxially grown film containing a single-crystal AlN film 25 to a Pt film 34b on an SOI substrate 50 having an epitaxially grown single-crystal PZT film 15, it becomes possible to obtain a single-crystal, high-performance piezoelectric film integrated device, similar to Embodiment 1.

[0063] In Embodiment 2, the alignment accuracy of the single-crystal PZT film 15 is improved compared to Embodiment 1. Therefore, in Embodiment 2, the output performance of the acoustic vibration wave is improved compared to Embodiments 1 and 3.

[0064] With respect to all other aspects, Embodiment 2 is the same as Embodiment 1.

[0065] (3) Embodiment 3 《3-1》Structure Figure 38 is a schematic side view showing the structure of the piezoelectric film integrated device 300. Figure 39 is a schematic top view showing the structure of the piezoelectric film integrated device 300. Figure 40 is a cross-sectional view of the piezoelectric film integrated device of Figure 39, cut along the line S40-S40.

[0066] In Embodiment 1, both the single-crystal PZT film 15 and the single-crystal AlN film 25 were grown on growth substrates 11 and 20, respectively, and then attached to the Pt film on the SOI substrate 33. In Embodiment 3, however, the single-crystal AlN film 25 is epitaxially grown on the SOI substrate 60. The upper surface of the SOI substrate 60 is a (111) plane. Therefore, it is possible to epitaxially grow a single crystal of the single-crystal AlN film 25 using the same process as in Embodiment 1.

[0067] 《3-2》Manufacturing method Figure 41 is a flowchart showing the manufacturing method of the piezoelectric film integrated device 300. Figure 42 shows steps ST301 and ST302 of Figure 41, Figure 43 shows step ST303 of Figure 41, Figure 44 shows step ST308 of Figure 41, and Figure 45 shows step ST309 of Figure 41.

[0068] First, as shown in Figure 42, a ZrO2 film 22 and a Pt film 23 as an electrode layer are formed on the main surface of the SOI substrate 60, which is the device substrate (step ST301). Next, as shown in Figure 42, an SRO film 24, a single-crystal AlN film 25, and a Pt film 26 are epitaxially grown on the Pt film 23 to form an epitaxially grown film consisting of the SRO film 24, the single-crystal AlN film 25, and the Pt film 26 (step ST302). Next, as shown in Figure 43, the shape of the epitaxially grown film including the single-crystal AlN film 25 is etched to a desired shape (for example, a circular shape) (step ST303). Next, the Pt film 23 as an electrode layer is etched to form a Pt film 34a as a first electrode and a Pt film 34b as a second electrode.

[0069] Next, individual pieces consisting of a single-crystal PZT film 15 and a Pt film 16 are held by a stamp 80 as a holding member, and as shown in Figure 44, the sacrificial layer, the SRO film 14, is etched to peel off the individual pieces, which are then moved onto the SOI substrate 60, which is the device substrate, and attached (steps ST305 to ST308). Here, a single-crystal PZT film 15, which was separately formed as described in Embodiment 1, is attached to the electrode. When attaching, the crystal orientation of the single-crystal AlN film 25 is confirmed by inspection, etc., and the crystal orientation of the single-crystal PZT film 15 and the single-crystal AlN film 25 are aligned as shown in Figure 23. The orientation of the single-crystal AlN film 25 is fixed on the SOI substrate 60, so the attachment angle of the single-crystal PZT film 15 is adjusted. Alternatively, after confirming the crystal orientation during the etching process shown in Figure 43, the piezoelectric film may be formed by masking so that it is in the same direction as in Embodiment 1.

[0070] Insulating films 35a and 35b are formed, and the electrodes of the piezoelectric film are connected to the electrode pattern with wiring films (lead-out wiring) 36a and 36b. Then, the SOI substrate 60 is etched in the same manner as in Embodiment 1 to manufacture the piezoelectric film integrated device 300 shown in Figures 38 to 40.

[0071] 《3-3》Effect In Embodiment 3, by attaching a single-crystal PZT film 15 to an electrode on an SOI substrate 60 having an epitaxially grown single-crystal AlN film 25, it becomes possible to obtain a single-crystal, high-performance piezoelectric film integrated device 300, similar to Embodiment 1.

[0072] In Embodiment 3, the alignment accuracy of the single-crystal AlN film 25 is improved compared to Embodiment 1. Therefore, in Embodiment 3, the detection sensitivity of acoustic vibration waves and the signal-to-noise ratio are improved compared to Embodiments 1 and 2.

[0073] With respect to all other matters, Embodiment 3 is the same as Embodiment 1 or 2.

[0074] (4) Modification Example 1 The piezoelectric film integrated device 500 of Modified Example 1 differs from the piezoelectric film integrated device 100 of Embodiment 1 in that the epitaxial growth film attached to the Pt film (first electrode) 34a on the SOI substrate 33 is composed of a Pt film 116, a single-crystal PZT film 15, and a Pt film 16, and the epitaxial growth film attached to the Pt film (second electrode) 34b on the SOI substrate 33 is composed of a Pt film 126, a single-crystal AlN film 25, and a Pt film 26. In all other respects, the piezoelectric film integrated device 500 of Modified Example 1 is the same as the piezoelectric film integrated device 100 of Embodiment 1.

[0075] Figure 46 is a cross-sectional view showing the state in which Pt film 13, SRO film 14, Pt film 116, single crystal PZT film 15, and Pt film 16 are sequentially epitaxially grown on a ZrO2 film 12 on a Si substrate 11. Figure 47 is a cross-sectional view showing the state in which Pt film 23, SRO film 24, Pt film 126, single crystal AlN film 25, and Pt film 26 are sequentially epitaxially grown on a ZrO2 film 22 on a Si substrate 21.

[0076] Figure 48 is a schematic cross-sectional view showing the structure of the piezoelectric film integrated device 500 of Modification 1. Figure 49 is a schematic top view showing the structure of the piezoelectric film integrated device 500 of Figure 48. In Figures 48 and 49, components that are the same as or corresponding to the components shown in Figures 1 to 4 (Embodiment 1) are denoted by the same reference numerals as in Figures 1 to 4. In the piezoelectric film integrated device 500 of Modification 1, an epitaxial growth film (shown in Figure 46) composed of a Pt film 116, a single crystal PZT film 15, and a Pt film 16 is attached to the Pt film 34a, and an epitaxial growth film (shown in Figure 47) composed of a Pt film 126, a single crystal AlN film 25, and a Pt film 26 is attached to the Pt film 34a. Apart from this point, the piezoelectric film integrated device 500 of Modification 1 is the same as the piezoelectric film integrated device 100 according to Embodiment 1.

[0077] Furthermore, an epitaxial growth film (shown in Figure 46) composed of a Pt film 116, a single-crystal PZT film 15, and a Pt film 16 can be used in place of the epitaxial growth film composed of a single-crystal PZT film 15 and a Pt film 16 in the piezoelectric film integrated device 200 according to Embodiment 2 (shown in Figures 30 to 32). Also, an epitaxial growth film (shown in Figure 47) composed of a Pt film 126, a single-crystal AlN film 25, and a Pt film 26 can be used in place of the epitaxial growth film composed of a single-crystal AlN film 15 and a Pt film 16 in the piezoelectric film integrated device 200 according to Embodiment 2 (shown in Figures 30 to 32 and Figures 42 to 45).

[0078] (5) Modified example 2 The piezoelectric film integrated devices 100, 200, 300 and the acoustic vibration sensor 400 according to this embodiment can be used not only as distance sensors but also as other sensors such as fingerprint sensors and vein (pulse wave) sensors.

[0079] Furthermore, a piezoelectric film integrated device in which pairs of single-crystal PZT films 15 and single-crystal AlN films 25 are arranged in a matrix makes it possible to detect the surface shape of an object to be detected. [Explanation of symbols]

[0080] 100, 100a, 200, 300, 500 Piezoelectric film integrated devices, 400 Acoustic vibration sensors, 11, 21 Growth substrates (single crystal Si substrates), 15 Single crystal PZT film (first single crystal piezoelectric film), 16 Pt film (third electrode), 14, 24 SRO film (orientation film), 25 Single crystal AlN film (second single crystal piezoelectric film), 26 Pt film (fourth electrode), 31 SiO2 portion, 32 Single crystal Si portion, 33, 50, 60 SOI substrates (substrates), 34a Pt film (first electrode), 34b Pt film (second electrode), 71-74 Holes, 116 Pt film, 126 Pt film.

Claims

1. circuit board and A first electrode provided on the substrate, A second electrode provided on the substrate, A first single-crystal piezoelectric film provided on the first electrode, A second single-crystal piezoelectric film is provided on the second electrode and has a crystal structure different from that of the first single-crystal piezoelectric film, A third electrode provided on the first single-crystal piezoelectric film, A fourth electrode provided on the second single-crystal piezoelectric film, It has, At least one of the first single-crystal piezoelectric film and the second single-crystal piezoelectric film is an epitaxially grown film that was grown on a growth substrate different from the substrate. A piezoelectric film integrated device characterized by the following features.

2. The substrate has a diaphragm provided in the lower region of the first single-crystal piezoelectric film and the second single-crystal piezoelectric film. The piezoelectric film integrated device according to feature 1.

3. The substrate is a Si substrate and SiO ２ It is an SOI substrate having a part and a single-crystal Si part, The diaphragm is made of SiO ２ Having a part and the single crystal Si part, The piezoelectric film integrated device according to feature 2.

4. The first single-crystal piezoelectric film is a single-crystal PZT film, a single-crystal KNN film, or a single-crystal barium titanate film. The second single-crystal piezoelectric film is a single-crystal AlN film, a single-crystal lithium tantalate film, or a single-crystal lithium niobate film. A piezoelectric film integrated device according to any one of claims 1 to 3.

5. The piezoelectric film integrated device according to any one of claims 1 to 4, characterized in that the first single-crystal piezoelectric film is an epitaxially grown film having a (001) plane which is a crystal plane parallel to the surface of the first electrode.

6. The first single-crystal piezoelectric film has a (001) plane, which is a crystal plane parallel to the surface of the first electrode, and is an epitaxially grown film attached to the surface of the first electrode. A piezoelectric film integrated device according to any one of claims 1 to 4.

7. The device further comprises an SRO film formed on the first electrode, The first single-crystal piezoelectric film has a (001) plane, which is a crystal plane parallel to the surface of the SRO film, and is an epitaxially grown film formed on the surface of the SRO film. A piezoelectric film integrated device according to any one of claims 1 to 4.

8. The piezoelectric film integrated device according to any one of claims 1 to 7, characterized in that the second single-crystal piezoelectric film is an epitaxially grown film having a (0001) plane which is a crystal plane parallel to the surface of the second electrode.

9. The second single-crystal piezoelectric film has a (0001) plane, which is a crystal plane parallel to the surface of the second electrode, and is an epitaxially grown film attached to the surface of the second electrode. A piezoelectric film integrated device according to any one of claims 1 to 7.

10. The device further comprises an SRO film formed on the second electrode, The second single-crystal piezoelectric film has a (0001) plane, which is a crystal plane parallel to the surface of the SRO film, and is an epitaxially grown film formed on the surface of the SRO film. A piezoelectric film integrated device according to any one of claims 1 to 6.

11. The crystal c-axis direction of the first single-crystal piezoelectric film and the crystal c-axis direction of the second single-crystal piezoelectric film are parallel to each other. A piezoelectric film integrated device according to any one of claims 1 to 10.

12. Having the piezoelectric film integrated device according to any one of claims 1 to 11, The first single-crystal piezoelectric film outputs an acoustic vibration wave consisting of at least one of sound waves and ultrasonic waves. The second single-crystal piezoelectric film detects the reflected waves of the acoustic vibration waves. An acoustic vibration sensor characterized by the following features.

13. A first epitaxial growth film containing a first single-crystal piezoelectric film is grown on a first crystal plane of a growth substrate. A second epitaxial growth film is grown on the second crystal plane of another growth substrate, the second epitaxial growth film containing a second single-crystal piezoelectric film having a crystal structure different from that of the first single-crystal piezoelectric film. The first epitaxial growth film, peeled off from the growth substrate, is attached to a substrate having electrodes, and the second epitaxial growth film, peeled off from the other growth substrate, is attached to the substrate. A method for manufacturing a piezoelectric film integrated device, characterized by the above.

14. A first epitaxial growth film containing a first single-crystal piezoelectric film is grown on a first crystal plane of a substrate having electrodes. A second epitaxial growth film is grown on a second crystal plane of the growth substrate, including a second single-crystal piezoelectric film having a crystal structure different from that of the first single-crystal piezoelectric film. The second epitaxial growth film, peeled off from the growth substrate, is attached to the electrodes of the substrate. A method for manufacturing a piezoelectric film integrated device, characterized by the above.

15. A first epitaxial growth film containing a first single-crystal piezoelectric film is grown on a first crystal plane of a growth substrate. A second epitaxial growth film is grown on a second crystal plane of a substrate having electrodes, the second epitaxial growth film containing a second single-crystal piezoelectric film having a crystal structure different from that of the first single-crystal piezoelectric film. The first epitaxial growth film, peeled off from the growth substrate, is attached to the electrodes of the substrate. A method for manufacturing a piezoelectric film integrated device, characterized by the above.

16. The crystal c-axis direction of the first single-crystal piezoelectric film and the crystal c-axis direction of the second single-crystal piezoelectric film are parallel to each other. A method for manufacturing a piezoelectric film integrated device according to any one of claims 13 to 15.

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