Elastic wave device and electronic module

Abstract

The embodiment of the present application provides an elastic wave device and an electronic module, the elastic wave device comprises: a support substrate; a thin film roughening layer arranged above the support substrate, the thin film roughening layer comprises a first surface towards the support substrate side and a second surface away from the support substrate side; an intermediate layer arranged on the side of the thin film roughening layer away from the support substrate, the intermediate layer at least comprises a high sound velocity material layer; a piezoelectric material layer arranged on the side of the intermediate layer away from the thin film roughening layer; the piezoelectric material layer has a bonding surface towards the support substrate side; the roughness of at least one of the first surface and the second surface is greater than the roughness of the bonding surface; the first surface and the second surface have a vertical distance d, the distance d is not constant in size at different positions of the thin film roughening layer, and the distance d is less than or equal to 0.01 lambda, wherein lambda is the wavelength of the elastic wave determined by the IDT electrode. The elastic wave device provided by the embodiment of the present application can maintain a higher Q value and lower stray.

Description

Technical Field

[0001] This invention relates to the field of electronic device technology, and more particularly to an elastic wave device and an electronic module. Background Technology

[0002] The market demands increasingly higher performance from filters, creating a strong need for high-quality filters. In SAW (surface acoustic wave) device design, achieving both higher Q values ​​and lower spurious emissions is a constant industry pursuit. However, in some designs, increasing the Q value can lead to higher spurious emissions, while reducing spurious emissions makes it difficult to guarantee a high Q value; a trade-off between Q value and spurious emissions is possible. Summary of the Invention

[0003] The purpose of this invention is to find a solution to balance the Q value and spurious emissions of elastic wave devices and to provide an elastic wave period and electronic module.

[0004] An embodiment of the present invention provides an elastic wave device, comprising: a support substrate; a thin film roughening layer disposed on the support substrate, the thin film roughening layer including a first surface facing the support substrate and a second surface facing away from the support substrate; an intermediate layer disposed on the side of the thin film roughening layer away from the support substrate, the intermediate layer including at least a hypersonic material layer; a piezoelectric material layer disposed on the side of the intermediate layer away from the thin film roughening layer; the sound speed of a volume wave propagating in the hypersonic material layer is higher than the sound speed of a volume wave propagating in the piezoelectric material layer; an IDT electrode disposed on the side of the piezoelectric material layer away from the intermediate layer; the piezoelectric material layer having a bonding surface facing the support substrate; the roughness of at least one of the first surface and the second surface is greater than the roughness of the bonding surface; a vertical distance d between the first surface and the second surface, the distance d being variable at different locations on the thin film roughening layer, the distance d being less than or equal to 0.01λ, where λ is the wavelength of the elastic wave determined by the IDT electrode.

[0005] An embodiment of the present invention also provides an elastic wave device, comprising: a support substrate; a thin film roughening layer disposed on the support substrate, the thin film roughening layer including a first surface facing the support substrate and a second surface facing away from the support substrate; at least one of the first surface and the second surface has a roughness greater than that of the second surface; an intermediate layer disposed on the side of the thin film roughening layer facing away from the support substrate, the intermediate layer including at least a hypersonic material layer; a piezoelectric material layer disposed on the side of the intermediate layer facing away from the thin film roughening layer; the sound speed of a volume wave propagating in the hypersonic material layer is higher than that of a volume wave propagating in the piezoelectric material layer; wherein the piezoelectric material layer has a bonding surface facing the support substrate; the roughness of at least one of the first surface and the second surface is greater than that of the bonding surface; a vertical distance d is between the first surface and the second surface, the distance d is not constant at different positions of the thin film roughening layer, and the distance d is less than or equal to 30 nm.

[0006] Another embodiment of the present invention provides an electronic module including the aforementioned elastic wave device.

[0007] The above embodiments of the present invention have at least one or more of the following beneficial effects: By setting a thin film roughening layer with a rough interface and ultra-thin dimensions, the rough interface of the thin film roughening layer causes diffuse reflection of stray acoustic waves propagating towards the supporting substrate, which can attenuate scattering and prevent symmetrical reflection back to the piezoelectric layer from interfering with the main SAW signal. This can reduce the generation of parasitic resonances, make the filter passband flatter, reduce insertion loss, and improve the Q value. Moreover, due to the thin thickness, the micro-morphological fluctuations caused by the rough interface are limited to the nanometer range by the film thickness, which prevents long-range periodic acoustic wave scattering and significantly suppresses scattering loss. Therefore, it is possible to achieve both a high Q value and low straying. Attached Figure Description

[0008] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0009] Figure 1 This is a schematic diagram of the stacked structure of a composite substrate provided in one embodiment of the present invention.

[0010] Figure 2 This is a schematic diagram of the stacked structure of a composite substrate provided in a specific embodiment of the present invention.

[0011] Figure 3 This is a schematic diagram of the stacked structure of a composite substrate provided in another specific embodiment of the present invention.

[0012] Figure 4 This is a schematic diagram of the stacked structure of a composite substrate provided in another specific embodiment of the present invention.

[0013] Figure 5 This is a top view of an elastic wave device provided in one embodiment of the present invention.

[0014] Figure 6 This is a schematic diagram of the structure of an elastic wave device provided in one embodiment of the present invention.

[0015] Figure 7 This is a schematic diagram of the mechanism of an elastic device provided in one embodiment of the present invention.

[0016] Figure 8 This is a schematic diagram of the structure of an electronic module in one embodiment of the present invention.

[0017] [Explanation of Labels in the Attached Image] 100. Elastic wave device; 10. Composite substrate; 11. Supporting substrate; 111. Silicon substrate layer; 112. Polycrystalline silicon layer; 12. Thin film roughening layer; 121. First surface; 122. Second surface; 13. Intermediate layer; 131. High-speed material layer; 132. Low-speed material layer; 1321. First low-speed material layer; 1322. Second low-speed material layer; 14. Piezoelectric material layer; 15. Adhesion layer; 20. Resonator; 21. IDT electrode; 211. Electrode finger; 212, busbar; 22, electrode pad; 23, reflector; 30, packaging substrate; 41, first sealing structure; 42, second sealing structure; 51, bump; 52, first conductive part; 53, first external terminal electrode; 54, second conductive part; 55, second external terminal electrode; 60, gap; 70, cover; 400, inductor; 500, sealing part; 600, integrated circuit component; 700, wiring substrate; 701, external connection terminal. Detailed Implementation

[0018] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0019] To enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0020] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0021] It should also be noted that the division of multiple embodiments in this invention is only for the convenience of description and should not constitute a special limitation. Features in various embodiments can be combined and referenced in each other without contradiction.

[0022] This invention provides an elastic wave device 100, which includes a composite substrate 10 and a resonator 20. Figure 1 This is a schematic diagram of the stacked structure of the composite substrate 10, which includes a support substrate 11, a thin film roughening layer 12, an intermediate layer 13 and a piezoelectric material layer 14 stacked sequentially.

[0023] The supporting substrate 11 can be, for example, a sapphire substrate, spinel substrate, silicon carbide substrate, polycrystalline silicon substrate, amorphous silicon substrate, or monocrystalline silicon substrate, but is not limited to the examples mentioned above. The supporting substrate 11 can be a single-layer material substrate or a multi-layer material substrate. For example... Figure 3 As shown, the support substrate includes a silicon substrate layer 111 and a polysilicon layer 112 disposed on the silicon substrate layer 111. The support substrate 11 has a front side and a back side facing each other. A thin film roughening layer 12 is disposed on the front side of the support substrate 11.

[0024] The piezoelectric material layer 14 has a bonding surface facing the support substrate 11. Figure 1The lower surface of the piezoelectric material layer 14. The thin film roughening layer 12 includes a first surface 121 facing the support substrate 11 and a second surface 122 facing away from the support substrate 11. The roughness of at least one of the first surface 121 and the second surface 122 is greater than the roughness of the bonding surface. Alternatively, it can be said that the undulation of at least one of the first surface 121 and the second surface 122 is greater than the undulation of the bonding surface. For example, only the roughness of the first surface 121 is greater than the roughness of the bonding surface; or only the roughness of the second surface 122 is greater than the roughness of the bonding surface; or both the roughness of the first surface 121 and the second surface 122 are greater than the roughness of the bonding surface. The bonding surface of the piezoelectric material layer 14 can be considered as a flat surface (in practice, due to process errors, measurement errors, etc., the surface roughness Sa of the bonding surface is allowed to be less than 10 nm, preferably less than 5 nm, and further less than 1 nm), which can also be understood as at least one of the first surface 121 and the second surface 122 being rough. For example, the first surface 121 may be rough while the second surface 122 may be smooth; or the first surface 121 may be smooth while the second surface may be rough; or both the first surface 121 and the second surface 122 may be rough. The roughness of the first surface 121 and the second surface 122 can be observed or measured by transmission electron microscopy (TEM), scanning electron microscopy (SEM), or atomic force microscopy (AFM).

[0025] The resonator 20 includes an IDT electrode 21 disposed on the side of the piezoelectric material layer 14 facing away from the intermediate layer 13. (See reference...) Figure 5 The IDT electrode 21 includes a plurality of electrode fingers 211 spaced apart along a first direction. IDT stands for Interdigital Transducer. The resonator 20 of the elastic wave device 100 may include the IDT electrode 21 and a pair of reflectors 23. The IDT electrode 21 can excite elastic waves. (Reference) Figure 5 The IDT electrode 21 includes a plurality of opposing electrode fingers 211, the electrode fingers 211 being arranged in the X direction (i.e., the first direction) and extending in the Y direction. In some embodiments, the IDT electrode 21 includes a busbar 212. The elastic wave device 100 has an elastic wave wavelength λ determined by the IDT electrode 21. In some embodiments, such as Figure 5 As shown, λ is equal to the center distance between two adjacent electrodes connected on the same busbar.

[0026] In some embodiments, there is a vertical distance d between the first surface 121 and the second surface 122. Since at least one of the first surface 121 and the second surface 122 is rough, this distance d is not constant at different locations of the roughened film layer 12. However, regardless of how this distance d varies, at any location of the roughened film layer 12, this distance d is less than or equal to 0.01λ. Alternatively, the distance d at the furthest point between the first surface 121 and the second surface 122 at different locations of the roughened film layer 12 can be called d_max, and d_max is less than or equal to 0.01λ. (Refer to...) Figure 1 For example, if the first surface 121 is rough and the second surface 122 is flat, then the distance from the lowest point of the first surface 121 to the second surface 122 is d_max. If the first surface 121 is flat and the second surface 122 is rough, then the distance from the highest point of the second surface 122 to the first surface 121 is d_max.

[0027] In other embodiments, in terms of actual distance values, regardless of how the distance d varies, at any location on the roughened thin film layer 12, the distance d is less than or equal to 30 nm. In other words, d_max is less than or equal to 30 nm.

[0028] The method for measuring the distance d is as follows: a transmission electron microscope (TEM) is used for measurement. Multiple segments of fixed unit length are randomly selected along the vertical cross-section of the elastic wave device to measure the distance d between the first surface 121 and the second surface 122. For example, the fixed unit length is 100 nm. The measurement data of each segment are summarized, and the largest value is d_max, and the smallest value can be recorded as d_min.

[0029] In this embodiment, the thin film roughening layer 12 is set to an ultra-thin size with a rough interface. This allows the thermal mismatch and deposited internal stress between the multilayer materials to be mitigated through the rough interface structure, reducing intrinsic acoustic loss caused by lattice defects and helping to maintain a high Q value. On the other hand, the main SAW signal is a surface acoustic wave propagating along the surface of the LT (piezoelectric material layer). The interlayer interface easily excites bulk acoustic waves and reflected clutter, resulting in increased insertion loss, deteriorated stopband, and parasitic resonance. The rough interface of the thin film roughening layer causes diffuse reflection of stray acoustic waves propagating towards the supporting substrate, which can attenuate scattering and prevent symmetrical reflection back to the piezoelectric layer from interfering with the main SAW signal. This can reduce the generation of parasitic resonance, make the filter passband flatter, reduce insertion loss, and improve the Q value.

[0030] Furthermore, due to its thinness, the microscopic morphological fluctuations caused by the rough interface are limited to the nanometer range by the film thickness, preventing long-range periodic acoustic wave scattering and significantly suppressing scattering loss. Specifically, controlling the distance d in the roughened layer 12 to less than or equal to 0.01λ can moderately scatter or dampen the transverse higher-order modes excited by the IDT electrode 21 without significantly affecting the propagation of the dominant mode, thereby reducing ripple and clutter in the filter passband. The bulk wave scattering loss caused by the roughened layer 12 is small and will not significantly worsen the device insertion loss; simultaneously, this distance d is significantly smaller than λ, avoiding the excitation of strong bulk wave resonance. Compared to a range greater than 0.01λ, this range does not cause significant acoustic energy leakage or mode conversion, thus maintaining a low device insertion loss. Therefore, the design of the distance d range in the roughened layer 12 achieves a good balance between spurious suppression and low loss, making it particularly suitable for high-performance RF SAW filters and resonators. Correspondingly, the value of λ can range from 1 to 6 μm, adapting to the operating wavelength of high-frequency elastic wave devices.

[0031] Furthermore, the average thickness of the roughened thin film layer 12 is less than or equal to 20 nm. The average thickness of the roughened thin film layer 12 is the arithmetic mean of the maximum thickness (thickest point) and the minimum thickness (thickest point). For example, if the first surface 121 is rough and the second surface 122 is flat, the distance from the highest point of the first surface 121 to the second surface 122 is the thickness of the thinnest part of the roughened thin film layer 12. For example, if the first surface 121 is flat and the second surface 122 is rough, the distance from the lowest point of the second surface 122 to the first surface 121 is the thickness of the thinnest part of the roughened thin film layer 12. For example, if both the first surface 121 and the second surface 122 are rough, the position with the smallest distance between the first surface 121 and the second surface 122 is the thickness of the thinnest part of the roughened thin film layer 12. In some embodiments, whether the first surface 121 or the second surface 122 is rough, the overall degree of undulation is basically the same, so the average thickness of the roughened thin film layer 12 can be regarded as the thickness of the roughened thin film layer 12. If a location exhibits significantly higher roughness or undulation than other areas, even under conditions of process error, that location should be considered an error and rejected. Maintaining a relatively thin overall thickness of the thin film roughening layer 12 can further ensure the effectiveness of stray particle suppression.

[0032] In actual measurement, the distance d at different positions of the roughened thin film layer 12 can be measured according to the aforementioned measurement method. The minimum value of distance d in the summarized data is recorded as d_min, and the maximum value is recorded as d_max. Then the average thickness of the roughened thin film layer 12 is equal to (d_min+d_max) / 2.

[0033] In some embodiments, the average thickness of the thin film roughening layer 12 is 3~20 nm. For example, the average thickness of the thin film roughening layer 12 can be 3 nm, 5 nm, 8 nm, 10 nm, 15 nm, 20 nm, etc. If it is less than 3 nm, it is difficult to achieve in terms of process, and if the layer thickness is too thin, it will not play a role in bonding enhancement, stress relief, or suppressing scattering loss. If the thin film roughening layer 12 is too thick (e.g., greater than 30 nm or higher), it will affect the Q value. Accordingly, in some embodiments, regardless of how the distance d changes, the distance d at any position is not less than 3 nm, or d_min is not less than 3 nm, which can ensure that the function of the thin film roughening layer 12 in suppressing scattering loss is properly realized.

[0034] In some embodiments, the average thickness of the thin film roughening layer 12 is 0.0005λ to 0.01λ. For example, in some embodiments, λ is 1 to 6 μm. For example, the average thickness of the thin film roughening layer 12 can be 0.001λ, 0.002λ, 0.005λ, 0.008λ, 0.01λ, etc. Correspondingly, in some embodiments, regardless of how the distance d changes, the distance d at any position is not less than 0.005λ, or d_min is not less than 0.005λ, which is also to ensure that the thin film roughening layer 12 can maintain its effect of reducing scattering loss.

[0035] An intermediate layer 13 is disposed on the side of the thin film roughening layer 12 facing away from the support substrate 11, and the intermediate layer 13 includes at least a hypersonic material layer 131. The sound speed of the bulk wave (SH wave, i.e., horizontal shear wave) propagating in the hypersonic material layer 131 is greater than the sound speed of the bulk wave propagating in the piezoelectric material layer 14. For example, the hypersonic material layer 131 can be silicon nitride, aluminum nitride, aluminum oxide, etc. The hypersonic material layer 131 is disposed so that the sound waves passing through the piezoelectric material layer 14 can be reflected, preventing sound wave leakage, thereby improving the Q value.

[0036] In some embodiments, refer to Figure 2 The intermediate layer 13 may further include a low-velocity material layer 132. The low-velocity material layer 132 is located between the high-velocity material layer 131 and the piezoelectric material layer 14. The sound speed of the bulk wave propagating in the low-velocity material layer 132 is lower than the sound speed of the bulk wave propagating in the piezoelectric material layer 14. The low-velocity material layer 132 is, for example, silicon dioxide, SiON, Ta2O5, a-Si, etc.

[0037] In some embodiments, refer to Figure 4The low-velocity material layer 132 includes a first low-velocity material layer 1321 and a second low-velocity material layer 1322, with an adhesive layer 15 disposed between the first low-velocity material layer 1321 and the second low-velocity material layer 1322. The materials of the first low-velocity material layer 1321 and the second low-velocity material layer 1322 can be the same or different, for example, both can be SiO2. Setting the low-velocity material layer 132 as multiple layers and connecting them with the adhesive layer 15 can enhance the adhesion between adjacent low-velocity material layers and regulate the stress of the composite substrate 10. In some embodiments, the adhesive layer 15 is, for example, a Ti layer, which has the effect of enhancing interfacial bonding and preventing delamination.

[0038] The piezoelectric material layer 14 is disposed on the side of the intermediate layer 13 opposite to the thin film roughening layer 12. The piezoelectric material layer 14 can be formed of piezoelectric materials such as lithium tantalate or lithium niobate.

[0039] In some embodiments, the thin film roughening layer 12 can be an oxide material layer, and more particularly, it can be a silicon-containing oxide layer, such as SiO2. x The thin film roughening layer 12 may contain only silicon and oxygen, or it may contain other elements. This thin film roughening layer 12 can be manufactured using a plasma dry surface roughening method. For example, a 30nm SiO2 layer is deposited on a support substrate, and gases such as Ar, CF4, and O2 are introduced. Plasma is then used to bombard the substrate, forming a nanoscale porous structure. By controlling the power, time, and gas ratio, the roughness Ra and the thickness of the thin film roughening layer 12 can be adjusted.

[0040] In addition, porous thin film deposition methods, such as plasma-enhanced chemical vapor deposition (PECVD), can also be used. Taking SiO2 as an example, the roughening layer 12 can be formed using SiH4 and oxygen as the reactant gases, and inert gases such as Ar and N2 as the carrier gas. By adjusting the oxygen content, the roughness and thickness of the roughened film can be controlled. If the oxygen content is sufficient, the reaction with SiH4 is more complete, resulting in fewer pores and lower roughness. According to the reaction formula SiH4 + 2O2 = SiO2 + 2H2O, if the molar ratio O2 / SiH4 ≥ 2, the reaction can be complete, forming a dense silicon oxide film without pores.

[0041] If the oxygen content is relatively low, for example, O2 / SiH4 < 2, and further, O2 / SiH4 < 1.8, a porous SiO2 film can be produced. However, O2 / SiH4 cannot be less than 1, otherwise it may lead to extremely large pores and the film is easy to fall off.

[0042] Furthermore, in some embodiments, the support substrate 11 is a silicon-containing substrate, such as monocrystalline silicon, polycrystalline silicon, amorphous silicon, silicon carbide, etc. In this case, the silicon in the support substrate 11 itself can serve as a silicon source. Only oxygen needs to be introduced for the reaction to occur. The oxygen enters the PECVD chamber, is dispersed into free radicals by radio frequency, and combines with silicon atoms on the surface of the support substrate 11 to form SiO2.

[0043] Taking monocrystalline silicon as an example, the temperature can be adjusted to 250℃-500℃, the O2 flow rate can be selected in the range of 50-300 sccm according to the wafer size and roughness requirements, the gas pressure can be 20-50 mTorr, and the RF power can be 150w to 350w.

[0044] The specific roughness and thickness range of the thin film roughening layer 12 can be changed by adjusting the temperature, radio frequency power, cavity gas pressure, and oxygen flow rate.

[0045] In other embodiments, the material contacted by the second surface 122 of the thin film roughening layer 12 is a silicon-containing material, for example, such as... Figure 2 In this embodiment, the hypersonic material layer 131 can be silicon nitride. Thus, the second side 122 of the thin film roughening layer 12 can also provide a silicon source, which can make both the first side 121 and the second side 122 of the thin film roughening layer 12 rough. In some cases, double-sided roughening can better suppress stray waves and suppress the bulk waves leaking downwards from the LT. However, it may also lose the master mode acoustic wave, affecting the Q value. Furthermore, due to process reasons, there may be problems such as poor uniformity and low yield. Therefore, this solution can be selected according to actual needs.

[0046] The elastic wave device 100 provided in this embodiment can be packaged in CSP (Chip Scale Package) or WLP (Wafer Level Package).

[0047] For example, refer to Figure 6This is a schematic diagram of a CSP-packaged elastic wave device 100. The elastic wave device 100 includes components (including a composite substrate 10 and a resonator 20), a packaging substrate 30, a first sealing structure 41, and a first external terminal electrode 53. The packaging substrate 30 is disposed opposite to the surface of the resonator 20 of the component, and a gap 60 is formed between the packaging substrate 30 and this surface. The first sealing structure 41 is disposed on the side of the packaging substrate 30 facing the component, covering the side of the component and the side facing away from the packaging substrate 30, so as to seal the gap 60 and seal the component. The resonator 20 includes an electrode pad 22 electrically connected to an IDT electrode 21. The electrode pad 22 is electrically connected to a first conductive portion 52 in the wiring pattern on the packaging substrate 30 through a bump 51. The first conductive portion 52 is electrically connected to the first external terminal electrode 53 on the side of the packaging substrate 30 facing away from the component, so that the elastic wave device 100 can be electrically connected to an external device through the first external terminal electrode 53.

[0048] The materials of the packaging substrate 30 and the first sealing structure 41 can refer to the substrate materials and sealing materials commonly used in existing CSP packaging. The electrode pads 22, bumps 51, first conductive parts 52 and first external terminal electrodes 53 are all made of materials with good conductivity. This embodiment is not limited to the above examples.

[0049] Reference Figure 7 This is a schematic diagram of an elastic wave device 100 using WLP packaging. The elastic wave device 100 includes components (including a composite substrate 10 and a resonator 20), a cover 70, a second sealing structure 42, and a second external terminal electrode. The cover 70 is disposed opposite to the side of the component where the resonator 20 is located, and a gap 60 is formed between the cover 70 and this surface. The resonator 20 includes an electrode pad 22 electrically connected to an IDT electrode 21. The area on the piezoelectric material layer 14 where the IDT electrode 21 is located is called the effective area. The second sealing structure 42 is disposed between the cover 70 and the component, and is disposed around the effective area. The second sealing structure 42 surrounds the electrode pad 22 to achieve sealing of the component. The second external terminal electrode 55, disposed on the surface of the cover 70 facing away from the component, is connected to the electrode pad 22 through a second conductive portion 54 penetrating the cover 70 and the second sealing structure 42, so that the elastic wave device 100 can be electrically connected to an external device through the second external terminal electrode 55.

[0050] The materials of the cover 70 and the second sealing structure 42 can refer to the cover materials and sealing materials used in existing WLP packaging. The electrode pads 22, the second conductive part 54 and the second external terminal electrode 55 are all made of materials with good conductivity. This embodiment is not limited.

[0051] Reference Figure 8The invention also provides an electronic module 1000, including a wiring substrate 700, a plurality of external connection terminals 701, an integrated circuit component 600, an elastic wave device 100 (including a composite substrate 10), an inductor 400, and a sealing portion 500. The plurality of external connection terminals 701 are formed on one surface of the wiring substrate 700 and are mounted on a pre-defined motherboard of a mobile communication terminal. The integrated circuit component 600 (which may be referred to as an IC) is mounted inside the wiring substrate 700. The integrated circuit component 600 includes a switching circuit and a noise amplifier. The elastic wave device 100 is mounted on the main surface of the wiring substrate 700. The inductor 400 is used for impedance matching; for example, the inductor 400 is an integrated passive device (IPD). The sealing portion 500 is used to seal the plurality of electronic components, including the elastic wave device 100, onto the wiring substrate 700.

[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. An elastic wave device, characterized in that, include: Support substrate (11); A thin film roughening layer (12) is disposed on the support substrate (11), the thin film roughening layer (12) includes a first surface (121) facing the support substrate (11) and a second surface (122) facing away from the support substrate (11). An intermediate layer (13) is disposed on the side of the thin film roughening layer (12) away from the support substrate (11), and the intermediate layer (13) includes at least a hypersonic material layer (131). A piezoelectric material layer (14) is disposed on the side of the intermediate layer (13) away from the thin film roughening layer (12); the sound speed of the bulk wave propagating in the hypersonic material layer (131) is higher than the sound speed of the bulk wave propagating in the piezoelectric material layer (14); An IDT electrode (21) is disposed on the side of the piezoelectric material layer (14) facing away from the intermediate layer (13); the piezoelectric material layer (14) has a bonding surface facing the support substrate (11); at least one of the first surface (121) and the second surface (122) has a roughness greater than that of the bonding surface; there is a vertical distance d between the first surface (121) and the second surface (122), the distance d is not constant at different locations on the thin film roughening layer (12), and the distance d is less than or equal to 0.01λ, where λ is the wavelength of the elastic wave determined by the IDT electrode (21).

2. The elastic wave device as described in claim 1, characterized in that, The distance d is not less than 0.005λ.

3. The elastic wave device as described in claim 1, characterized in that, The roughness of the first surface (121) is greater than that of the second surface (122).

4. The elastic wave device as described in claim 1, characterized in that, At least one of the supporting substrate (11) and the hypersonic material layer (131) contains silicon, and the composition of the thin film roughening layer contains silicon and oxygen.

5. The elastic wave device as described in claim 1, characterized in that, The intermediate layer (13) includes a low-sonic material layer (132) located between the high-sonic material layer (131) and the piezoelectric material layer (14), wherein the sound speed of the body wave propagating in the low-sonic material layer (132) is lower than the sound speed of the body wave propagating in the piezoelectric material layer (14).

6. The elastic wave device as described in claim 1, characterized in that, The average thickness of the roughened thin film layer is 3~20nm.

7. The elastic wave device as described in claim 1, characterized in that, The value of λ is 1 to 6 micrometers.

8. An elastic wave device, characterized in that, include: Support substrate (11); A thin film roughening layer (12) is disposed on the support substrate (11), the thin film roughening layer (12) includes a first surface (121) facing the support substrate (11) and a second surface (122) facing away from the support substrate (11). An intermediate layer (13) is disposed on the side of the thin film roughening layer (12) away from the support substrate (11), and the intermediate layer (13) includes at least a hypersonic material layer (131). A piezoelectric material layer (14) is disposed on the side of the intermediate layer (13) away from the thin film roughening layer (12); the sound speed of the bulk wave propagating in the hypersonic material layer (131) is higher than the sound speed of the bulk wave propagating in the piezoelectric material layer (14); The piezoelectric material layer (14) has a bonding surface facing the support substrate (11); the roughness of at least one of the first surface (121) and the second surface (122) is greater than the roughness of the bonding surface; there is a vertical distance d between the first surface (121) and the second surface (122), the distance d is not constant at different positions of the thin film roughening layer (12), and the distance d is less than or equal to 30 nm.

9. The elastic wave device as described in claim 8, characterized in that, The distance d is not less than 3nm.

10. An electronic module, characterized in that, Includes the elastic wave device as described in any one of claims 1 to 9.

Images