Surface acoustic wave resonance device, forming method thereof and filter

Abstract

The invention discloses a surface acoustic wave resonance device, a forming method thereof and a filter. An intermediate layer on the substrate, the intermediate layer including a plurality of defect sub-layers having crystal defects; a piezoelectric layer on the intermediate layer; and the electrode structure is positioned on the piezoelectric layer. The crystal defects in the middle layer can form a charge trap, and a conductive plane can be prevented from being formed on the surface of the substrate, so that the generated parasitic coupling phenomenon is effectively inhibited, the electric loss is reduced, and the Q value of the resonance device or the electromechanical coupling coefficient (Kt) of the resonance device is improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a surface acoustic wave resonator device and a forming method thereof, and a filter. Background Art

[0002] The RF front-end chips of wireless communication devices include power amplifiers, antenna switches, RF filters, multiplexers, and low-noise amplifiers, etc. Among them, RF filters include piezoelectric surface acoustic wave (SAW) filters, piezoelectric bulk acoustic wave (BAW) filters, micro-electro-mechanical system (MEMS) filters, integrated passive devices (IPD) filters, etc.

[0003] The quality factor (Q value) of the SAW resonator is relatively high. The RF filter made of SAW resonator has low insertion loss and high out-band rejection, that is, SAW filter, which is the mainstream RF filter used in wireless communication devices such as mobile phones and base stations. The SAW resonator has a negative temperature coefficient of frequency (TCF), that is, when the temperature rises, the resonant frequency of the resonator decreases, and when the temperature decreases, the resonant frequency increases. This reduces the reliability and stability of the SAW filter. In order to improve the characteristics of the resonant frequency of the SAW resonator drifting with the operating temperature, a temperature compensation layer is added to the piezoelectric layer. The temperature compensation layer has a frequency temperature coefficient opposite to that of the piezoelectric layer. The combination of the two makes the overall frequency temperature coefficient of the resonator tend to zero, improving the reliability and stability of the filter. This SAW resonator containing a temperature compensation layer is called a temperature compensated SAW (TC-SAW) resonator, and the filter composed of TC-SAW resonators is called a TC-SAW filter.

[0004] However, there are still many problems with surface acoustic wave resonator devices. Summary of the invention

[0005] The problem solved by the present invention is to provide a surface acoustic wave resonance device and a forming method thereof, and a filter, so as to improve the Q value of the resonance device or the electromechanical coupling coefficient (Kt) of the resonance device.

[0006] To solve the above problems, the technical solution of the present invention provides a surface acoustic wave resonance device, including: a substrate; an intermediate layer located on the substrate, the intermediate layer including a plurality of defect sublayers with crystal defects; a piezoelectric layer located on the intermediate layer; and an electrode structure located on the piezoelectric layer.

[0007] Optionally, the crystal defects of each defect sub-layer include: one or more of point defects, line defects and surface defects.

[0008] Optionally, the point defect includes: a vacancy defect or an impurity defect.

[0009] Optionally, the vacancy defect includes: a Frankel vacancy or a Schottky vacancy.

[0010] Optionally, the impurity defects include: interstitial impurities or substitutional impurities.

[0011] Optionally, the line defect includes: a dislocation defect.

[0012] Optionally, the dislocation defect includes: edge dislocation or screw dislocation.

[0013] Optionally, the surface defect includes: a translation interface, a twin interface or a grain boundary.

[0014] Optionally, the translation interface includes: surface state defects.

[0015] Optionally, the surface state defects include: reconstructed atoms or relaxed surfaces.

[0016] Optionally, the material of the intermediate layer includes: silicon dioxide, glass, silicon oxynitride, tantalum oxide, or a compound obtained by adding fluorine, carbon or boron to silicon dioxide, or any one of materials having the above materials as main components.

[0017] Optionally, the plurality of defective sub-layers are evenly distributed in the middle layer.

[0018] Optionally, the distance between adjacent defective sub-layers is less than or equal to half the thickness of the intermediate layer.

[0019] Optionally, the plurality of defect sub-layers are located on a side of the intermediate layer close to the substrate.

[0020] Optionally, it also includes: a protective layer located on the piezoelectric layer, wherein the protective layer covers the electrode structure.

[0021] Optionally, it further includes: a temperature compensation layer located on the piezoelectric layer, wherein the temperature compensation layer covers the electrode structure.

[0022] Correspondingly, the technical solution of the present invention also provides a method for forming a surface acoustic wave resonance device, including: providing a substrate; forming a piezoelectric layer; forming an intermediate layer, the intermediate layer including a plurality of defect sublayers with crystal defects, the piezoelectric layer being connected to the substrate through the intermediate layer; and forming an electrode structure on the piezoelectric layer.

[0023] Optionally, the intermediate layer is formed on the substrate, and the piezoelectric layer and the intermediate layer are bonded.

[0024] Optionally, the intermediate layer is formed on one side of the piezoelectric layer, and the intermediate layer and the substrate are bonded.

[0025] Optionally, forming the intermediate layer includes: forming a plurality of defect sub-layers having the crystal defects in the intermediate layer, and the crystal defects of each defect sub-layer include: one or more of point defects, line defects and surface defects.

[0026] Optionally, after forming the electrode structure, the method further includes: forming a protective layer on the piezoelectric layer, wherein the protective layer covers the electrode structure.

[0027] Optionally, after forming the electrode structure, the method further includes: forming a temperature compensation layer on the piezoelectric layer, wherein the temperature compensation layer covers the electrode structure.

[0028] Correspondingly, the technical solution of the present invention further provides a filter, comprising: a surface acoustic wave resonance device as described in any one of the above items.

[0029] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0030] In the surface acoustic wave resonator device of the technical solution of the present invention, the crystal defects in the intermediate layer can form charge traps, which can prevent the formation of a conductive plane on the surface of the substrate, thereby effectively suppressing the parasitic coupling phenomenon and reducing electrical losses, thereby improving the Q value of the resonant device or the electromechanical coupling coefficient (Kt) of the resonant device.

[0031] Furthermore, the plurality of defect sublayers are located on the side of the intermediate layer close to the substrate, which can make the defect sublayers away from the piezoelectric layer, further suppress the parasitic coupling phenomenon generated between the piezoelectric layer and the substrate, reduce electrical loss, and thereby improve the Q value of the resonant device or the electromechanical coupling coefficient (Kt) of the resonant device.

[0032] In the method for forming a surface acoustic wave resonant device of the technical solution of the present invention, the crystal defects in the intermediate layer can form charge traps, which can prevent the formation of a conductive plane on the surface of the substrate, thereby effectively suppressing the parasitic coupling phenomenon and reducing electrical losses to improve the Q value of the resonant device or the electromechanical coupling coefficient (Kt) of the resonant device.

[0033] Furthermore, the plurality of defect sublayers are located on the side of the intermediate layer close to the substrate, which can make the defect sublayers away from the piezoelectric layer, further suppress the parasitic coupling phenomenon generated between the piezoelectric layer and the substrate, reduce electrical losses, and improve the Q value of the resonance device or the electromechanical coupling coefficient (Kt) of the resonance device. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 and Figure 2 It is a schematic diagram of the structure of a surface acoustic wave resonance device;

[0035] Figures 3 to 9 is a structural schematic diagram of each step of a method for forming a surface acoustic wave resonator device in an embodiment of the present invention;

[0036] Fig.10 is a schematic structural diagram of a surface acoustic wave resonance device in another embodiment of the present invention;

[0037] Fig.11 Schematic diagram of a defect of a Frankel vacancy in an embodiment of the present invention;

[0038] Fig.12 is a schematic diagram of a defect of a Schottky vacancy in another embodiment of the present invention;

[0039] Fig.13 is a schematic diagram of defects of interstitial impurities in another embodiment of the present invention;

[0040] Fig.14 is a schematic diagram of defects of substitutional impurities in another embodiment of the present invention;

[0041] Fig.15 is a schematic diagram of an edge dislocation defect in another embodiment of the present invention;

[0042] Fig.16 is a schematic diagram of a screw dislocation defect in another embodiment of the present invention;

[0043] Fig.17 is a schematic diagram of defects in reconstructing atoms in another embodiment of the present invention;

[0044] Fig.18 is a schematic diagram of defects on a relaxed surface in another embodiment of the present invention;

[0045] Fig.19 is a schematic structural diagram of a surface acoustic wave resonance device in another embodiment of the present invention;

[0046] Fig. 20 It is a schematic structural diagram of a surface acoustic wave resonance device in another embodiment of the present invention. DETAILED DESCRIPTION

[0047] As described in the background art, there are still many problems with the surface acoustic wave resonance device, which will be described in detail below with reference to the accompanying drawings.

[0048] Figure 1 and Figure 2 It is a structural schematic diagram of a surface acoustic wave resonance device.

[0049] Please refer to Figure 1 and Figure 2 , Figure 2 yes Figure 1 The schematic cross-sectional view along line AA in the figure shows a surface acoustic wave resonance device, comprising: a substrate 105; an intermediate layer 106 located on the substrate 105; a piezoelectric layer 100 located on the intermediate layer 106; an electrode structure located on the piezoelectric layer 100, the electrode structure comprising a first bus 101 and a second bus 102 arranged in parallel along a first direction X; a plurality of first electrode strips 103 connected to the first bus 101, the plurality of first electrode strips 103 being arranged in parallel along a second direction Y, the first direction X being perpendicular to the second direction Y; a plurality of second electrode strips 104 connected to the second bus 102, the plurality of second electrode strips 104 being arranged in parallel along the second direction Y, the first electrode strips 103 and the second electrode strips 104 being staggered, and the first electrode strips 103 and the second electrode strips 104 having overlapping areas along the second direction Y.

[0050] In this embodiment, the material of the intermediate layer 106 includes silicon dioxide, glass, silicon oxynitride, tantalum oxide, or a compound obtained by adding fluorine, carbon or boron to silicon dioxide, or any one of the materials having the above materials as main components.

[0051] However, there is a parasitic surface conductance (PSC) effect at the interface between the intermediate layer 106 and the substrate 105 made of the above material, and parasitic coupling occurs between the piezoelectric layer 100 and the substrate 105, resulting in electrical loss, thereby reducing the Q value or electromechanical coupling coefficient (Kt).

[0052] On this basis, the present invention provides a surface acoustic wave resonance device and a method for forming the same, as well as a filter. The crystal defects in the intermediate layer can form charge traps, which can prevent the formation of a conductive plane on the surface of the substrate, thereby effectively suppressing the parasitic coupling phenomenon and reducing electrical losses, thereby improving the Q value of the resonance device or the electromechanical coupling coefficient (Kt) of the resonance device.

[0053] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0054] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0055] Figures 3 to 9 is a structural schematic diagram of each step of a method for forming a surface acoustic wave resonator device in an embodiment of the present invention; Fig.10 is a schematic structural diagram of a surface acoustic wave resonance device in another embodiment of the present invention; Fig.11 Schematic diagram of a defect of a Frankel vacancy in an embodiment of the present invention; Fig.12 Schematic diagram of a defect of a Schottky vacancy in another embodiment of the present invention.

[0056] Please refer to Figure 3 , providing a substrate 200.

[0057] The substrate 200 mainly plays a supporting role in the subsequent device manufacturing process. The substrate 200 is made of a material with a resistivity higher than 1000 ohm / cm.

[0058] The material of the substrate 200 includes: single crystal silicon, glass, sapphire, and silicon carbide.

[0059] In this embodiment, the substrate 200 is made of single crystal silicon.

[0060] In this embodiment, after providing the substrate 200, the process further includes: forming an intermediate layer. Figure 4 .

[0061] Please refer to Figure 4 , an intermediate layer 201 is formed on the substrate 200, and the intermediate layer 201 includes a plurality of defect sub-layers 202 having crystal defects.

[0062] In this embodiment, the material of the intermediate layer 201 includes silicon dioxide, glass, silicon oxynitride, tantalum oxide, or a compound obtained by adding fluorine, carbon or boron to silicon dioxide, or any one of the materials having the above materials as main components.

[0063] In this embodiment, three defective sub-layers 202 stacked in sequence are formed in the intermediate layer 201 as an example.

[0064] In other embodiments, the number of the defective sub-layers 202 of the intermediate layer 201 may also be 2 or greater than 3.

[0065] The crystal defects of each defect sub-layer 202 include: one or more of point defects, line defects and surface defects.

[0066] It should be noted that the crystal defects can be formed by common process methods used by those skilled in the art. There are many factors affecting the formation of the crystal defects, such as ion implantation and thermal diffusion, which can both produce crystal point defects.

[0067] Among them, atoms or molecules are ionized to form plasma, which carries a certain amount of charge. The ions are accelerated by the electric field and the magnetic field is used to change their direction of movement, so that the ions can be controlled to enter the crystal with a certain energy. This process will cause a large number of point defects such as vacancies and gaps in the crystal, as well as complex defects formed by vacancies combined with other impurities. The formation of defects is related to the energy, mass, dose, target material and target temperature of the injected ions.

[0068] Crystal defects can also be generated by thermal diffusion, which is divided into interstitial diffusion and substitutional diffusion. At high temperatures, lattice atoms vibrate near the lattice equilibrium position, and matrix atoms have a certain probability of obtaining enough energy to break away from the lattice and become interstitial atoms, creating a vacancy. At this time, the adjacent impurity atoms can occupy this vacancy. This is substitutional diffusion. If the interstitial impurity atoms move from one position to another and do not occupy the lattice point, this is interstitial diffusion. Vacancy defects and impurity defects are easily generated during the diffusion process.

[0069] In this embodiment, the crystal defects of each defect sub-layer 202 are point defects, and the point defects are vacancy defects.

[0070] Please refer to Fig.11 In this embodiment, the vacancy defect is a Frankel vacancy.

[0071] Please refer to Fig.12 In other embodiments, the vacancy defect may also be a Schottky vacancy.

[0072] In this embodiment, a spacer sublayer 211 is further included on each defect sublayer 202 , and the spacer sublayer 211 does not have the crystal defects.

[0073] In this embodiment, the plurality of defective sub-layers 202 are evenly distributed in the middle layer 201 .

[0074] Please continue to refer to Figure 4 In this embodiment, since the number of defective sublayers 202 is greater than 2 layers, the distance D between adjacent defective sublayers 202 (i.e., the distance between the top surfaces or bottom surfaces of adjacent defective sublayers 202) is less than half the thickness of the intermediate layer 201.

[0075] In other embodiments, if the number of defective sub-layers 202 is 2, the distance between adjacent defective sub-layers 202 (ie, the distance between the top surfaces or bottom surfaces of adjacent defective sub-layers 202 ) is equal to half the thickness of the intermediate layer 201 .

[0076] In this embodiment, each of the spacer sub-layers 211 and the defect sub-layer 202 thereunder may be formed by using one growth process.

[0077] In other embodiments, each spacer sublayer 201 may be formed by an additional growth process.

[0078] In other embodiments, the intermediate layer 201 may be entirely the defect sub-layer 202 without the spacer sub-layer 211 .

[0079] In this embodiment, the thickness of the intermediate layer 201 is greater than 5 um.

[0080] After forming the intermediate layer 201, the method further includes: forming a piezoelectric layer, wherein the piezoelectric layer is connected to the substrate 200 through the intermediate layer 201. For the specific formation process, please refer to Figure 5 and Figure 6 .

[0081] Please refer to Figure 5 , forming a piezoelectric layer 203.

[0082] Please continue to refer to Figure 5 In this embodiment, the method for forming the piezoelectric layer 203 includes: providing a sacrificial substrate 210; and forming the piezoelectric layer 203 on the sacrificial substrate 210. The sacrificial substrate 210 is used to provide a temporary substrate for forming the piezoelectric layer 203. After the piezoelectric layer 203 and the intermediate layer 201 are subsequently bonded, the sacrificial substrate 210 needs to be removed.

[0083] The material of the piezoelectric layer 203 includes: lithium tantalate, lithium niobate, lead zirconate titanate, lead magnesium niobate-lead titanate, aluminum nitride, aluminum nitride alloy, gallium nitride or zinc oxide.

[0084] In this embodiment, the material of the piezoelectric layer 203 is lithium niobate.

[0085] Please refer to Figure 6 , bonding the piezoelectric layer 203 and the intermediate layer 201 ; after bonding the piezoelectric layer 203 and the intermediate layer 201 , removing the sacrificial substrate 210 .

[0086] In this embodiment, after the piezoelectric layer 203 is bonded, the piezoelectric layer 203 is located on the intermediate layer 201 .

[0087] By adding the intermediate layer 201 and the substrate 200 below the piezoelectric layer 203, the two will have a difference in acoustic impedance due to different materials, which can effectively prevent energy from leaking downward, thereby improving the Q value of the resonant device. Since the intermediate layer 201 and the substrate 200 are solid materials, their heat transfer coefficient is greater than the heat transfer coefficient of air, which can improve the heat dissipation of the resonant device, increase the power capacity of the resonant device, and improve the performance of the resonant device.

[0088] In addition, the crystal defects in the intermediate layer 201 can form charge traps, thereby preventing the formation of a conductive plane on the surface of the substrate 200, thereby effectively suppressing the parasitic coupling phenomenon and reducing electrical losses, thereby improving the Q value of the resonant device or the electromechanical coupling coefficient (Kt) of the resonant device.

[0089] In other embodiments, the piezoelectric layer 203 may also be stacked directly on the intermediate layer 201 .

[0090] In other embodiments, the piezoelectric layer 203 and the intermediate layer 201 may be sequentially formed on the sacrificial substrate 210, and then the intermediate layer 201 may be bonded to the substrate 200, and then the sacrificial substrate 210 may be removed after bonding.

[0091] In other embodiments, the piezoelectric layer 203 and the first bonding layer can be sequentially formed on the sacrificial substrate 210, a second bonding layer can be formed on the substrate 200, the first bonding layer and the second bonding layer can be bonded to form the intermediate layer 201, crystal defects can be formed in the first bonding layer and / or the second bonding layer, and the sacrificial substrate 210 can be removed after bonding.

[0092] In other embodiments, the method for forming the piezoelectric layer 203 may further include: providing a piezoelectric substrate (not shown); forming an intermediate layer 201 on the substrate 200; bonding the piezoelectric substrate to the intermediate layer 201; and after bonding the piezoelectric substrate and the intermediate layer 201, thinning the piezoelectric substrate to form the piezoelectric layer 203.

[0093] In other embodiments, the method for forming the piezoelectric layer 203 may further include: providing a piezoelectric substrate (not shown), forming the intermediate layer 201 on one side of the piezoelectric substrate; bonding the intermediate layer 201 to the substrate 200; and after bonding the intermediate layer 201 and the substrate 200, thinning the piezoelectric substrate to form the piezoelectric layer 203.

[0094] Please refer to Figure 7 and Figure 8 , Figure 8 yes Figure 7 In the cross-sectional schematic diagram along line BB, an electrode structure is formed on the piezoelectric layer 203.

[0095] Forming the electrode structure includes: forming a first bus 204 and a second bus 205 arranged in parallel along a first direction X; forming a plurality of first electrode strips 206 connected to the first bus 204, wherein the plurality of first electrode strips 206 are arranged in parallel along a second direction Y, wherein the first direction X is perpendicular to the second direction Y; forming a plurality of second electrode strips 207 connected to the second bus 205, wherein the plurality of second electrode strips 207 are arranged in parallel along the second direction Y, wherein the first electrode strips 206 and the second electrode strips 207 are alternately arranged, and wherein the first electrode strips 206 and the second electrode strips 207 have overlapping areas along the second direction Y.

[0096] The material of the electrode structure includes, but is not limited to, one of the following: molybdenum, tungsten, copper, platinum, rhenium, osmium, iridium, tantalum, gold, and hafnium.

[0097] Please refer to Fig. 9 , Fig. 9 and Figure 8 In the same viewing direction, a temperature compensation layer 208 is formed on the piezoelectric layer 203 , and the temperature compensation layer 208 covers the electrode structure; and a protection layer 209 is formed on the temperature compensation layer 208 .

[0098] The temperature compensation layer 208 has the opposite temperature frequency shift characteristics to the piezoelectric layer 203, which can reduce the temperature coefficient of frequency (TCF) and tend to 0 ppm / r, thereby improving the characteristic of the operating frequency drift of the surface acoustic wave resonator device with the operating temperature, and having higher frequency-temperature stability. The surface acoustic wave resonator device including the temperature compensation layer 208 is called a temperature compensated surface acoustic wave resonator device (i.e., TC-SAW resonator).

[0099] The material of the temperature compensation layer 208 includes silicon dioxide, silicon oxynitride, silicon oxyfluoride or silicon oxycarbide.

[0100] In this embodiment, the material of the temperature compensation layer 208 is silicon dioxide.

[0101] The protective layer 209 is used to protect the electrode structure and prevent oxidation and damage to the electrode structure.

[0102] The material of the protective layer 209 includes, but is not limited to, one of the following: silicon dioxide, silicon nitride, aluminum nitride, silicon oxynitride, aluminum oxide, and silicon carbide.

[0103] In this embodiment, the material of the protection layer 209 is silicon nitride.

[0104] Please refer to Fig.10 , Fig.10 and Figure 8 In the same viewing direction, in other embodiments, the temperature compensation layer 208 may not be formed, and only the protection layer 209 is formed on the piezoelectric layer 203 , and the protection layer 209 covers the electrode structure.

[0105] Correspondingly, the present invention also provides a surface acoustic wave resonance device in the embodiment, please continue to refer to Figure 8 and Fig. 9 , comprising: a substrate 200; an intermediate layer 201 located on the substrate 200, wherein the intermediate layer 201 comprises a plurality of defect sub-layers 202 having crystal defects; a piezoelectric layer 203 located on the intermediate layer 201; and an electrode structure located on the piezoelectric layer 203.

[0106] By adding the intermediate layer 201 and the substrate 200 below the piezoelectric layer 203, the two will have a difference in acoustic impedance due to different materials, which can effectively prevent energy from leaking downward, thereby improving the Q value of the resonant device. Since the intermediate layer 201 and the substrate 200 are solid materials, their heat transfer coefficient is greater than the heat transfer coefficient of air, which can improve the heat dissipation of the resonant device, increase the power capacity of the resonant device, and improve the performance of the resonant device.

[0107] In addition, the crystal defects in the intermediate layer 201 can form charge traps, thereby preventing the formation of a conductive plane on the surface of the substrate 200, thereby effectively suppressing the parasitic coupling phenomenon and reducing electrical losses, thereby improving the Q value of the resonant device or the electromechanical coupling coefficient (Kt) of the resonant device.

[0108] The crystal defects of each defect sub-layer 202 include: one or more of point defects, line defects and surface defects.

[0109] In this embodiment, the crystal defects of each defect sub-layer 202 are point defects, and the point defects are vacancy defects.

[0110] Please refer to Fig.11 In this embodiment, the vacancy defect is a Frankel vacancy.

[0111] Please refer to Fig.12 In other embodiments, the vacancy defect may also be a Schottky vacancy.

[0112] In this embodiment, the material of the intermediate layer 201 includes silicon dioxide.

[0113] In this embodiment, a spacer sublayer 211 is further included on each defect sublayer 202 , and the spacer sublayer 211 does not have the crystal defects.

[0114] In this embodiment, the plurality of defective sub-layers 202 are evenly distributed in the middle layer 201 .

[0115] In this embodiment, since the number of defective sublayers 202 is greater than 2, the distance between adjacent defective sublayers 202 (i.e., the distance between the top surfaces or bottom surfaces of adjacent defective sublayers 202 ) is less than half the thickness of the intermediate layer 201 .

[0116] In other embodiments, if the number of defective sublayers 202 is 2, the distance between adjacent defective sublayers (ie, the distance between the top surfaces or bottom surfaces of adjacent defective sublayers) is equal to half the thickness of the intermediate layer 201 .

[0117] In other embodiments, the intermediate layer 201 may be entirely the defect sub-layer 202 without the spacer sub-layer 211 .

[0118] In this embodiment, the thickness of the intermediate layer 201 is greater than 5 um.

[0119] The electrode structure includes: a first bus 204 and a second bus 205 arranged in parallel along a first direction X; a plurality of first electrode strips 206 connected to the first bus 204, wherein the plurality of first electrode strips 206 are arranged in parallel along a second direction Y, wherein the first direction X is perpendicular to the second direction Y; and a plurality of second electrode strips 207 connected to the second bus 205, wherein the plurality of second electrode strips 207 are arranged in parallel along the second direction Y, wherein the first electrode strips 206 and the second electrode strips 207 are alternately arranged, and along the second direction Y, the first electrode strips 206 and the second electrode strips 207 have overlapping areas.

[0120] The material of the electrode structure includes, but is not limited to, one of the following: molybdenum, tungsten, copper, platinum, rhenium, osmium, iridium, tantalum, gold, and hafnium.

[0121] Please continue to refer to Fig. 9 In this embodiment, it also includes: a temperature compensation layer 208 located on the piezoelectric layer 203, the temperature compensation layer 208 covers the electrode structure; and a protection layer 209 located on the temperature compensation layer 208.

[0122] The temperature compensation layer 208 has the opposite temperature frequency shift characteristics to the piezoelectric layer 203, which can reduce the temperature coefficient of frequency (TCF) and tend to 0 ppm / r, thereby improving the characteristic of the operating frequency drift of the surface acoustic wave resonator device with the operating temperature, and having higher frequency-temperature stability. The surface acoustic wave resonator device including the temperature compensation layer 208 is called a temperature compensated surface acoustic wave resonator device (i.e., TC-SAW resonator).

[0123] The material of the temperature compensation layer 208 includes silicon dioxide, silicon oxynitride, silicon oxyfluoride or silicon oxycarbide.

[0124] In this embodiment, the material of the temperature compensation layer 208 is silicon dioxide.

[0125] The protective layer 209 is used to protect the electrode structure and prevent oxidation and damage to the electrode structure.

[0126] The material of the protective layer 209 includes, but is not limited to, one of the following: silicon dioxide, silicon nitride, aluminum nitride, silicon oxynitride, aluminum oxide, and silicon carbide.

[0127] In this embodiment, the material of the protection layer 209 is silicon nitride.

[0128] Please continue to refer to Fig.10 In other embodiments, the temperature compensation layer 208 may not be formed, and only the protective layer 209 may be formed on the piezoelectric layer 203, and the protective layer 209 covers the electrode structure.

[0129] Fig.13 is a schematic diagram of defects of interstitial impurities in another embodiment of the present invention; Fig.14 Schematic diagram of defects caused by substitutional impurities in another embodiment of the present invention.

[0130] In this embodiment, in the above embodiment ( Fig. 9 or Fig.10 ) is further described on the basis of the method for forming a surface acoustic wave resonance device, which is different from the above embodiment in that: the point defect is an impurity defect. The following will be specifically described in conjunction with the accompanying drawings.

[0131] Please refer to Fig.13 In this embodiment, the impurity defects are interstitial impurities.

[0132] Please refer to Fig.14 In other embodiments, the impurity defects are substitutional impurities.

[0133] Correspondingly, a surface acoustic wave resonance device is also provided in the embodiment of the present invention, please continue to refer to Fig.13 or Fig.14 The rest of the structure is the same as the surface acoustic wave resonance device described in the above embodiment, except that: the point defect is an impurity defect.

[0134] Please continue to refer to Fig.13 In this embodiment, the impurity defects are interstitial impurities.

[0135] Please continue to refer to Fig.14 In other embodiments, the impurity defects are substitutional impurities.

[0136] Fig.15 is a schematic diagram of an edge dislocation defect in another embodiment of the present invention; Fig.16 Schematic diagram of a screw dislocation defect in another embodiment of the present invention.

[0137] In this embodiment, in the above embodiment ( Fig. 9 or Fig.10 ), the method for forming a surface acoustic wave resonator device is further described based on the above embodiment, which is different from the above embodiment in that: the crystal defect is a line defect, and the line defect is a dislocation defect. The following will be specifically described in conjunction with the accompanying drawings.

[0138] The formation of dislocation defects usually includes: due to the influence of temperature gradient, concentration gradient, mechanical vibration, etc., the growing crystal deflects or bends, causing phase differences between adjacent crystal blocks, and dislocations are formed between them; there are a large number of vacancies in the crystal, and the aggregation of vacancies can form dislocations; certain interfaces (such as second phase particles, twins, grain boundaries, etc.) and microcracks inside the crystal often have stress concentration due to the effects of thermal stress and structural stress, and dislocations are easily generated in this area. Dislocation defects can be formed using the process methods commonly used by those skilled in the art.

[0139] Please refer to Fig.15 In this embodiment, the dislocation defect is an edge dislocation.

[0140] Please refer to Fig.16 In other embodiments, the dislocation defect is a screw dislocation.

[0141] Correspondingly, a surface acoustic wave resonance device is also provided in the embodiment of the present invention, please continue to refer to Fig.15 or Fig.16 , the rest of the structure is the same as the surface acoustic wave resonance device recorded in the above embodiment, the difference is that: the crystal defect is a line defect, and the line defect is a dislocation defect.

[0142] Please continue to refer to Fig.15In this embodiment, the dislocation defect is an edge dislocation.

[0143] Please continue to refer to Fig.16 In other embodiments, the dislocation defect is a screw dislocation.

[0144] Fig.17 is a schematic diagram of defects in reconstructing atoms in another embodiment of the present invention; Fig.18 It is a schematic diagram of defects on a relaxed surface in another embodiment of the present invention.

[0145] In this embodiment, in the above embodiment ( Fig. 9 or Fig.10 ), the method for forming a surface acoustic wave resonator device is further described based on the above embodiment, which is different from the above embodiment in that the crystal defect is a surface defect, and the surface defect includes a translation interface, a twin interface or a grain boundary. The following will be specifically described in conjunction with the accompanying drawings.

[0146] In this embodiment, the translation interface is a surface state defect.

[0147] Please refer to Fig.17 In this embodiment, the surface state defect is a reconstructed atom. Reconstructed atoms refer to the periodicity of the surface atomic layer in the horizontal direction being different from that of the atoms in the body, that is, the horizontal spacing between the surface atoms is d1, which is different from the horizontal spacing between the atoms in the body is d2, but the interlayer spacing in the vertical direction is the same as that of the atoms in the body. Reconstructed atomic defects can be formed by roughening (grinding, polishing), heat treatment or homoepitaxial growth, etc., which are commonly used by those skilled in the art.

[0148] Please refer to Fig.18 In other embodiments, the surface state defect is a relaxed surface. A relaxed surface refers to a phenomenon in which the vertical distance d3 between the surface layers is expanded and compressed compared to the vertical distance d4 between the surface and the atomic body, while the horizontal atomic distance is the same. Relaxed surface defects can be formed by annealing, mechanical deformation caused by applying stress, or growth process, etc., which are commonly used by those skilled in the art.

[0149] Correspondingly, a surface acoustic wave resonance device is also provided in the embodiment of the present invention, please continue to refer to Fig.17 or Fig.18 The rest of the structure is the same as the surface acoustic wave resonance device described in the above embodiment, except that: the crystal defect is a surface defect, and the surface defect includes: a translation interface, a twin interface or a grain boundary.

[0150] In this embodiment, the translation interface is a surface state defect.

[0151] Please refer to Fig.17In this embodiment, the surface state defects are reconstructed atoms. Reconstructed atoms refer to the periodicity of the surface atomic layer in the horizontal direction being different from that of the atoms in the body, that is, the horizontal spacing between the surface atoms is d1, which is different from the horizontal spacing between the atoms in the body is d2, but the interlayer spacing in the vertical direction is the same as that of the atoms in the body.

[0152] Please refer to Fig.18 In other embodiments, the surface state defect is a relaxed surface. A relaxed surface refers to a phenomenon in which the vertical distance d3 between surface layers is expanded and compressed compared to the vertical distance d4 between the surface and the atomic body, while the horizontal atomic distance is the same.

[0153] Fig.19 It is a schematic structural diagram of a surface acoustic wave resonance device in another embodiment of the present invention.

[0154] In this embodiment, in the above embodiment ( Figure 3 ) is further described on the basis of the method for forming the surface acoustic wave resonance device, which is different from the above embodiment ( Fig. 9 ) is that: the plurality of defect sub-layers are located in a side of the intermediate layer 201 close to the substrate 200. The following will be described in detail with reference to the accompanying drawings.

[0155] Please refer to Fig.19 , an intermediate layer 201 is formed on the substrate 200, and the intermediate layer 201 includes a plurality of defect sub-layers 300 having crystal defects.

[0156] In this embodiment, the plurality of defect sublayers 300 are located on the side of the intermediate layer 201 close to the substrate 200, which can make the defect sublayer 300 away from the piezoelectric layer 203, further suppress the parasitic coupling phenomenon generated between the piezoelectric layer 203 and the substrate 200, reduce electrical loss, and thus improve the Q value of the resonant device or the electromechanical coupling coefficient (Kt) of the resonant device.

[0157] In this embodiment, a spacer sub-layer 301 is further formed above the plurality of defective sub-layers 300 , and the spacer sub-layer 301 does not have the crystal defects.

[0158] In this embodiment, the spacer sub-layer 301 and the defect sub-layer 300 located at the top may be formed by using one growth process.

[0159] In other embodiments, the spacer sublayer 211 may also be formed by using an additional growth process.

[0160] Please continue to refer to Fig.19After forming the intermediate layer 201, the piezoelectric layer 203, the electrode structure, the temperature compensation layer 208 and the protective layer 209 are also formed. For the specific formation process, please refer to Figures 5 to 9 , and related instructions have been described, which will not be repeated here.

[0161] In other embodiments, the temperature compensation layer 208 may not be formed, and the protective layer 209 may be formed only on the piezoelectric layer 203. For a specific formation process, please refer to Fig.10 , and related instructions have been described, which will not be repeated here.

[0162] Correspondingly, a surface acoustic wave resonance device is also provided in the embodiment of the present invention, please continue to refer to Fig.19 , the rest of the structures are the same as those in the above embodiment ( Fig. 9 or Fig.10 ) is the same as the surface acoustic wave resonance device described in ), except that: the multiple defect sublayers 300 are located in the side of the intermediate layer 201 close to the substrate 200, and a spacer sublayer 301 is also formed above the multiple defect sublayers 300, and the spacer sublayer 301 does not have the crystal defects.

[0163] In this embodiment, the plurality of defect sublayers 300 are located on the side of the intermediate layer 201 close to the substrate 200, which can make the defect sublayers away from the piezoelectric layer 203, further suppress the parasitic coupling phenomenon between the piezoelectric layer 203 and the substrate 200, reduce electrical losses, and thus improve the Q value of the resonant device or the electromechanical coupling coefficient (Kt) of the resonant device.

[0164] Fig. 20 It is a schematic structural diagram of a surface acoustic wave resonance device in another embodiment of the present invention.

[0165] In this embodiment, in the above embodiment ( Figure 3 ) is further described on the basis of the method for forming the surface acoustic wave resonance device, which is different from the above embodiment ( Fig. 9 ) is that: before forming the intermediate layer 201, it also includes: forming an isolation layer 400 between the substrate 200 and the intermediate layer 201. The following will be described in detail with reference to the accompanying drawings.

[0166] Please refer to Fig. 20 , an isolation layer 400 is formed on the substrate 200 .

[0167] The material of the isolation layer 400 includes but is not limited to one of the following: silicon dioxide, silicon nitride, silicon carbide or an amorphous insulating material.

[0168] In this embodiment, the isolation layer 400 is made of silicon dioxide.

[0169] In this embodiment, the thickness of the isolation layer 400 is less than 2 nm, or is between 20 nm and 20 um.

[0170] Please continue to refer to Fig. 20 After forming the isolation layer 400, the intermediate layer 201 is formed on the isolation layer 400. For details about the intermediate layer 201, please refer to Figure 4 , Figures 11 to 19 , and related instructions, will not be repeated here.

[0171] By forming the isolation layer 400 between the substrate 200 and the intermediate layer 201, the isolation layer 400 can block the heat transferred from the substrate 200 in the subsequent heat treatment process, thereby preventing the crystal defects in the intermediate layer 201 from being repaired due to heat, thereby causing the intermediate layer's charge capture performance to decrease, thereby ensuring the capture performance of the intermediate layer and improving the Q value of the resonant device or the electromechanical coupling coefficient (Kt) of the resonant device.

[0172] Please continue to refer to Fig. 20 , forming a piezoelectric layer 203 , and bonding the piezoelectric layer 203 to the intermediate layer 201 .

[0173] In other embodiments, the isolation layer 400 is formed on the substrate 200 ; the intermediate layer 201 is formed on the piezoelectric layer 203 , and the intermediate layer 201 and the isolation layer 400 are bonded.

[0174] In other embodiments, the intermediate layer 201 and the isolation layer 400 may be sequentially formed on the piezoelectric layer 203, and then the isolation layer 400 is bonded to the substrate 200.

[0175] For the piezoelectric layer, please refer to Figures 5 and 6 As well as the relevant instructions, I will not repeat them again.

[0176] Please continue to refer to Fig. 20 After forming the piezoelectric layer, an electrode structure is formed on the piezoelectric layer. For details about the electrode structure, please refer to Figure 7 and Figure 8 , and related instructions have been described, which will not be repeated here.

[0177] Please continue to refer to Fig. 20 After forming the piezoelectric layer, a temperature compensation layer and a protective layer are formed on the piezoelectric layer. For details about the temperature compensation layer and the protective layer, please refer to Fig. 9 , and related instructions have been described, which will not be repeated here.

[0178] In other embodiments, the temperature compensation layer may not be formed and a protective layer may be formed directly. For details, please refer to Fig.10 , and related instructions have been described, which will not be repeated here.

[0179] Correspondingly, an embodiment of the present invention further provides a filter, comprising: a surface acoustic wave resonance device as described in any of the above embodiments.

[0180] It should be understood that the examples and embodiments herein are merely illustrative and that various modifications and corrections may be made by those skilled in the art without departing from the spirit and scope of the present invention as defined in this application and the appended claims.

Claims

1. A surface acoustic wave resonance device, characterized in that: include: substrate; an intermediate layer located on the substrate, the intermediate layer comprising a plurality of defect sublayers having crystal defects; a piezoelectric layer located on the intermediate layer; An electrode structure is located on the piezoelectric layer.

2. The surface acoustic wave resonator device according to claim 1, characterized in that: The crystal defects of each defect sub-layer include one or more of point defects, line defects and surface defects.

3. The surface acoustic wave resonator device according to claim 2, characterized in that: The point defects include: vacancy defects or impurity defects.

4. The surface acoustic wave resonator device according to claim 3, characterized in that: The vacancy defects include Frankel vacancies or Schottky vacancies.

5. The surface acoustic wave resonator device according to claim 3, characterized in that: The impurity defects include interstitial impurities or substitutional impurities.

6. The surface acoustic wave resonator device according to claim 2, characterized in that: The line defects include: dislocation defects.

7. The surface acoustic wave resonator device according to claim 6, characterized in that: The dislocation defect includes edge dislocation or screw dislocation.

8. The surface acoustic wave resonator device according to claim 2, characterized in that: The surface defects include: translational interfaces, twin interfaces or grain boundaries.

9. The surface acoustic wave resonator device according to claim 8, characterized in that: The translation interface includes: surface state defects.

10. The surface acoustic wave resonator device according to claim 9, characterized in that: The surface state defects include: reconstructed atoms or relaxed surfaces.

11. The surface acoustic wave resonator device according to claim 1, characterized in that: The material of the intermediate layer includes silicon dioxide, glass, silicon oxynitride, tantalum oxide, or a compound obtained by adding fluorine, carbon, or boron to silicon dioxide, or any one of materials containing the above materials as main components.

12. The surface acoustic wave resonator device according to claim 1, characterized in that: The plurality of defect sub-layers are uniformly distributed in the intermediate layer.

13. The surface acoustic wave resonator device according to claim 12, characterized in that: The distance between adjacent defective sub-layers is less than or equal to half the thickness of the intermediate layer.

14. The surface acoustic wave resonator device according to claim 1, characterized in that: The plurality of defect sub-layers are located in a side of the intermediate layer close to the substrate.

15. The surface acoustic wave resonator device according to claim 1, characterized in that: Also includes: A protection layer is located on the piezoelectric layer, and the protection layer covers the electrode structure.

16. The surface acoustic wave resonator device according to claim 1, characterized in that: Also includes: A temperature compensation layer is located on the piezoelectric layer, and the temperature compensation layer covers the electrode structure.

17. A method for forming a surface acoustic wave resonator device, characterized in that: include: providing a substrate; forming a piezoelectric layer; forming an intermediate layer, the intermediate layer comprising a plurality of defect sublayers having crystal defects, the piezoelectric layer being connected to the substrate through the intermediate layer; An electrode structure is formed on the piezoelectric layer.

18. The method for forming a surface acoustic wave resonator device according to claim 17, wherein: The intermediate layer is formed on the substrate, and the piezoelectric layer and the intermediate layer are bonded.

19. The method for forming a surface acoustic wave resonator device according to claim 17, wherein: The intermediate layer is formed on one side of the piezoelectric layer, and the intermediate layer and the substrate are bonded.

20. The method for forming a surface acoustic wave resonator device according to claim 17, wherein: Forming the intermediate layer includes: forming a plurality of defect sub-layers having the crystal defects in the intermediate layer, and the crystal defects of each defect sub-layer include: one or more of point defects, line defects and surface defects.

21. The method for forming a surface acoustic wave resonator device according to claim 17, wherein: After forming the electrode structure, the method further includes: forming a protection layer on the piezoelectric layer, wherein the protection layer covers the electrode structure.

22. The method for forming a surface acoustic wave resonator device according to claim 17, wherein: After forming the electrode structure, the method further includes: forming a temperature compensation layer on the piezoelectric layer, wherein the temperature compensation layer covers the electrode structure.

23. A filter, characterized in that: include: A surface acoustic wave resonator device as claimed in any one of claims 1 to 18.

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