Surface acoustic wave temperature compensation resonator, preparation method, filter and electronic equipment

Abstract

The embodiment of the invention provides a surface acoustic wave temperature compensation resonator, a preparation method, a filter and electronic equipment, relates to the technical field of semiconductors, and is used for reducing stray modes of the surface acoustic wave temperature compensation resonator. A surface acoustic wave temperature compensated resonator is provided. The surface acoustic wave temperature compensation resonator comprises a piezoelectric substrate, an interdigital transducer and a covering layer. The interdigital transducer is disposed on one surface of the piezoelectric substrate. The covering layer covers the surface, provided with the interdigital transducer, of the piezoelectric substrate, and the interdigital transducer is located between the covering layer and the piezoelectric substrate; the surface, away from the piezoelectric substrate, of the covering layer is provided with a plurality of grooves arranged in an array mode. The surface acoustic wave temperature compensation resonator is used for a filter.

Description

Technical Field

[0001] This application relates to the field of semiconductor technology, and particularly to a surface acoustic wave temperature-compensated resonator, a preparation method thereof, a filter, and an electronic device. Background Art

[0002] With the rapid evolution of 5G technology, the radio frequency front-end of terminal devices needs to support more and more frequency bands, and surface acoustic wave temperature-compensated resonators are widely used. However, in related technologies, a large number of spurious modes are generated in the surface acoustic wave temperature-compensated resonator, resulting in a reduction in the performance of the surface acoustic wave temperature-compensated resonator. Summary of the Invention

[0003] The purpose of the embodiments of this application is to provide a surface acoustic wave temperature-compensated resonator, a preparation method thereof, a filter, and an electronic device, which are used to reduce the spurious modes of the surface acoustic wave temperature-compensated resonator.

[0004] To achieve the above purpose, the embodiments of this application provide the following technical solutions:

[0005] On the one hand, a surface acoustic wave temperature-compensated resonator is provided. The surface acoustic wave temperature-compensated resonator includes: a piezoelectric substrate, interdigital transducers, and a covering layer. The interdigital transducers are disposed on one surface of the piezoelectric substrate. The covering layer covers the surface of the piezoelectric substrate where the interdigital transducers are disposed, and the interdigital transducers are located between the covering layer and the piezoelectric substrate; wherein, a plurality of grooves arranged in an array are provided on the surface of the covering layer facing away from the piezoelectric substrate.

[0006] Among them, in the surface acoustic wave temperature-compensated resonator provided by the embodiments of this application, the piezoelectric substrate can provide support for the interdigital transducers, and the covering layer can protect the piezoelectric substrate and the interdigital transducers. By providing a plurality of grooves arranged in an array on one surface of the covering layer facing away from the piezoelectric substrate, the resonance formed between the surface of the covering layer facing away from the piezoelectric substrate and the interdigital transducers can be reduced, so that the spurious modes formed between the surface of the covering layer facing away from the piezoelectric substrate and the interdigital transducers can be reduced, and the introduction of other spurious modes can be reduced, thereby improving the performance of the surface acoustic wave temperature-compensated resonator.

[0007] In some embodiments, the grooves are strip-shaped and extend along a first direction. A plurality of grooves are arranged in a row, and in a row of grooves, the plurality of grooves are arranged at equal intervals in a second direction in sequence, wherein the first direction and the second direction are cross-set and are both parallel to the piezoelectric substrate.

[0008] Among them, the multiple grooves are strip-shaped and are arranged at equal intervals along the second direction. Therefore, the multiple grooves are arranged periodically, which can reduce the spurious modes formed between the surface of the cover layer facing away from the piezoelectric substrate and the interdigital transducer, and reduce the introduction of other spurious modes, thereby improving the performance of the surface acoustic wave temperature compensation resonator. In addition, when preparing the multiple grooves arranged periodically, the processing technology has simple process steps and low processing costs.

[0009] In some embodiments, the groove penetrates the cover layer along the first direction.

[0010] Among them, by making the groove penetrate the cover layer along the first direction, the length of the groove can be increased, and the lengths of the respective grooves in the first direction can be made the same, thereby improving the regularity of the arrangement of the multiple grooves, reducing the spurious modes formed between the surface of the cover layer facing away from the piezoelectric substrate and the interdigital transducer, and reducing the introduction of other spurious modes, thereby improving the performance of the surface acoustic wave temperature compensation resonator.

[0011] In some embodiments, the interdigital transducer includes a first bus bar, a second bus bar, multiple first electrode fingers, and multiple second electrode fingers. The first bus bar and the second bus bar are arranged opposite to each other; the multiple first electrode fingers are connected to the first bus bar and are arranged in sequence along the extension direction of the first bus bar and protrude towards the second bus bar; the multiple second electrode fingers are connected to the second bus bar and are arranged in sequence along the extension direction of the second bus bar and protrude towards the first bus bar; among them, the first electrode fingers and the second electrode fingers are alternately arranged in sequence between the first bus bar and the second bus bar, and the first electrode fingers and the second electrode fingers are arranged at intervals. Among them, the first direction is parallel to the extension direction of the first bus bar; or, the first direction is parallel to the extension direction of the first electrode finger; or, the first direction intersects with the extension direction of the first bus bar and intersects with the extension direction of the first electrode finger.

[0012] Among them, the strip-shaped groove can extend along the extension direction of the first bus bar, or can extend along the extension direction of the first electrode finger, or the extension direction of the strip-shaped groove can also intersect with both the extension direction of the first bus bar and the extension direction of the first electrode finger. Therefore, the extension direction of the strip-shaped groove can be designed according to the structure of the surface acoustic wave temperature compensation resonator.

[0013] In some embodiments, when the resonance frequency of the surface acoustic wave temperature compensation resonator is greater than or equal to 1.87 GHz and less than or equal to 1.93 GHz, the period length of the groove is greater than or equal to 500 nm and less than or equal to 1300 nm. Among them, the period length of the groove is the sum of the width of the groove in the second direction and the distance between two adjacent grooves in the second direction.

[0014] Such a setting can enable the surface acoustic wave temperature-compensated resonator to have a better spurious suppression effect.

[0015] In some embodiments, when the resonant frequency of the surface acoustic wave temperature-compensated resonator is greater than or equal to 0.57 GHz and less than or equal to 0.61 GHz, the depth of the groove is greater than or equal to 0.02P and less than or equal to 0.08P. Here, P is the period length of the groove, and the period length of the groove is equal to the sum of the width of the groove in the second direction and the distance between two adjacent grooves in the second direction.

[0016] Such a setting can enable the surface acoustic wave temperature-compensated resonator to have a better spurious suppression effect.

[0017] In some embodiments, when the resonant frequency of the surface acoustic wave temperature-compensated resonator is greater than or equal to 0.58 GHz and less than or equal to 0.61 GHz, the width of the groove in the second direction is greater than or equal to 0.1P and less than or equal to 0.4P; where P is the period length of the groove, and the period length of the groove is equal to the sum of the width of the groove in the second direction and the distance between two adjacent grooves in the second direction.

[0018] Such a setting can enable the surface acoustic wave temperature-compensated resonator to have a better spurious suppression effect.

[0019] In some embodiments, the cover layer includes a temperature compensation layer. The temperature compensation layer covers the surface of the piezoelectric substrate where the interdigital transducer is provided, and the interdigital transducer is located between the temperature compensation layer and the piezoelectric substrate. The groove is provided on the surface of the temperature compensation layer facing away from the piezoelectric substrate.

[0020] Among them, by providing a temperature compensation layer in the surface acoustic wave temperature-compensated resonator, the surface acoustic wave temperature-compensated resonator can have a smaller TCF (temperature coefficient of frequency), thereby reducing the deterioration of the performance of the surface acoustic wave temperature-compensated resonator in high-temperature and low-temperature environments. By providing the groove on the temperature compensation layer, the structural complexity of the surface acoustic wave temperature-compensated resonator can be reduced, and the cost can be reduced.

[0021] In some embodiments, the cover layer includes a temperature compensation layer and a dielectric layer. The temperature compensation layer covers the surface of the piezoelectric substrate where the interdigital transducer is provided, and the interdigital transducer is located between the temperature compensation layer and the piezoelectric substrate. The dielectric layer covers the surface of the temperature compensation layer facing away from the piezoelectric substrate, and the groove is provided on the surface of the dielectric layer facing away from the piezoelectric substrate.

[0022] Among them, by providing the groove on the dielectric layer, therefore, no loss will be generated to the temperature compensation layer when setting the groove, thereby ensuring the TCF of the temperature compensation layer.

[0023] On the other hand, a filter is provided, which includes a plurality of cascaded surface acoustic wave temperature compensation resonators; wherein, the surface acoustic wave temperature compensation resonator is the surface acoustic wave temperature compensation resonator provided in some of the above embodiments.

[0024] In yet another aspect, an electronic device is provided, which includes a filter and a circuit board, and both the filter and the processor are disposed on the circuit board. Wherein, the filter is the filter provided in some of the above embodiments.

[0025] In still another aspect, a method for manufacturing a surface acoustic wave temperature compensation resonator is provided. The manufacturing method includes: forming an interdigital transducer on a piezoelectric substrate; forming a covering layer on the surface of the piezoelectric substrate where the interdigital transducer is disposed, and the covering layer covers the surface of the interdigital transducer facing away from the piezoelectric substrate; forming a plurality of grooves arranged in an array on the surface of the covering layer facing away from the piezoelectric substrate.

[0026] The manufacturing method provided by the embodiments of the present application is used to manufacture the surface acoustic wave temperature compensation resonator provided in some of the above embodiments. Therefore, it has all the beneficial effects of the surface acoustic wave temperature compensation resonator provided in some of the above embodiments, and will not be elaborated herein.

[0027] In some embodiments, forming a covering layer on the surface of the piezoelectric substrate where the interdigital transducer is disposed, and the covering layer covers the surface of the interdigital transducer facing away from the piezoelectric substrate, includes: forming a temperature compensation layer on the surface of the piezoelectric substrate where the interdigital transducer is disposed, and the temperature compensation layer covers the surface of the interdigital transducer facing away from the piezoelectric substrate. Forming a plurality of grooves arranged in an array on the surface of the covering layer facing away from the piezoelectric substrate, includes: forming a plurality of grooves arranged in an array on the surface of the temperature compensation layer facing away from the piezoelectric substrate.

[0028] The manufacturing method provided by the embodiments of the present application is used to manufacture the surface acoustic wave temperature compensation resonator provided in some of the above embodiments. Therefore, it has all the beneficial effects of the surface acoustic wave temperature compensation resonator provided in some of the above embodiments, and will not be elaborated herein.

[0029] In some embodiments, forming a covering layer on the surface of the piezoelectric substrate where the interdigital transducer is disposed, and the covering layer covers the surface of the interdigital transducer facing away from the piezoelectric substrate, includes: forming a temperature compensation layer on the surface of the piezoelectric substrate where the interdigital transducer is disposed, and the temperature compensation layer covers the surface of the interdigital transducer facing away from the piezoelectric substrate; forming a dielectric layer on the surface of the temperature compensation layer facing away from the piezoelectric substrate. Forming a plurality of grooves arranged in an array on the surface of the covering layer facing away from the piezoelectric substrate, includes: forming a plurality of grooves arranged in an array on the surface of the dielectric layer facing away from the piezoelectric substrate.

[0030] Among them, by arranging the groove on the dielectric layer, therefore, the temperature compensation layer will not be damaged when the groove is arranged, so as to ensure the TCF of the temperature compensation layer. Description of the Drawings

[0031] In order to more clearly illustrate the technical solutions in the present application, the drawings required to be used in some embodiments of the present application will be briefly introduced below. Obviously, the drawings in the following description are only the drawings of some embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings. In addition, the drawings in the following description can be regarded as schematic diagrams, and are not limitations on the actual dimensions of the products involved in the embodiments of the present application, the actual processes of the methods, the actual timings of the signals, etc.

[0032] Figure 1 Structural schematic diagram of the electronic device provided by the embodiment of the present application;

[0033] Figure 2 A structural diagram of a filter provided by the embodiment of the present application;

[0034] Figure 3 For Figure 2 Structural diagram of the surface acoustic wave temperature compensation resonator in

[0035] Figure 4 For Figure 3 Structural diagram of the interdigital transducer in the first perspective in

[0036] Figure 5 For Figure 3 Cross-sectional view at A-A';

[0037] Figure 6 Admittance curve diagram corresponding to the first resonator;

[0038] Figure 7 Admittance curve diagram corresponding to the second resonator;

[0039] Figure 8 For Figure 2 Another structural diagram of the surface acoustic wave temperature compensation resonator in

[0040] Figure 9 For Figure 8 Structural diagram of the surface acoustic wave temperature compensation resonator in the third perspective in

[0041] Figure 10 Structural diagram of the surface of the covering layer facing away from the piezoelectric substrate;

[0042] Figure 11 For Figure 2 Another structural diagram of the surface acoustic wave temperature compensation resonator in

[0043] Figure 12 For Figure 2 Another structural diagram of the surface acoustic wave temperature compensation resonator in

[0044] Figure 13 Admittance curves corresponding to the third resonator, the fourth resonator, the fifth resonator, and the sixth resonator;

[0045] Figure 14 Admittance curves corresponding to the seventh resonator, the eighth resonator, the ninth resonator, and the tenth resonator;

[0046] Figure 15 Admittance curves corresponding to the eleventh resonator, the twelfth resonator, the thirteenth resonator, and the fourteenth resonator;

[0047] Figure 16 Flowchart of the preparation method of the surface acoustic wave temperature compensation resonator provided by the embodiment of the present application;

[0048] Figure 17 Another flowchart of the preparation method of the surface acoustic wave temperature compensation resonator provided by the embodiment of the present application;

[0049] Figure 18 Another flowchart of the preparation method of the surface acoustic wave temperature compensation resonator provided by the embodiment of the present application. Detailed implementation manners

[0050] Next, the technical solutions in some embodiments of the present disclosure will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of the present disclosure.

[0051] Unless the context otherwise requires, throughout the specification and claims, the term "comprise" and its other forms, such as the third-person singular form "comprises" and the present participle form "comprising", are to be construed in an open, inclusive sense, i.e., "including, but not limited to". In the description of the specification, terms such as "some embodiments", "example", or "some examples" are intended to indicate that a particular feature, structure, material, or characteristic related to the embodiment or example is included in at least one embodiment or example of the present disclosure. The schematic representations of the above terms do not necessarily refer to the same embodiment or example. In addition, the specific features, structures, materials, or characteristics may be included in any one or more embodiments or examples in any appropriate manner.

[0052] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the embodiments of the present disclosure, unless otherwise specified, the meaning of "plural" is two or more.

[0053] As used herein, "parallel", "perpendicular", and "equal" include the stated cases and cases similar to the stated cases, where the range of the similar cases is within an acceptable deviation range, which is determined by those of ordinary skill in the art considering the measurements being discussed and the errors associated with the measurements of a particular quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, where the acceptable deviation range for approximate parallelism may be, for example, within 5° deviation; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, where the acceptable deviation range for approximate perpendicularity may also be, for example, within 5° deviation. "Equal" includes absolute equality and approximate equality, where the acceptable deviation range for approximate equality may be, for example, that the difference between the two equal ones is less than or equal to 5% of either one of them.

[0054] It should be understood that when a layer or element is referred to as being on another layer or substrate, it may be directly on the other layer or substrate, or there may be an intermediate layer between the layer or element and the other layer or substrate.

[0055] Exemplary embodiments are described herein with reference to cross-sectional views and / or plan views that are idealized exemplary drawings. In the drawings, the thickness of layers and the area of regions are enlarged for clarity. Thus, variations in the shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are contemplated. Accordingly, exemplory embodiments should not be construed as limited to the shapes of the regions shown herein, but include shape deviations resulting from, for example, manufacturing. For example, an etched region shown as rectangular will generally have curved features. Thus, the regions shown in the drawings are schematic in nature, and their shapes are not intended to depict the actual shape of the regions of the device and are not intended to limit the scope of the exemplory embodiments.

[0056] An embodiment of the present application provides an electronic device, and the technical solution of the present application can be applied to various electronic devices including filters. The electronic device can be deployed on land, including indoor or outdoor, handheld or vehicle-mounted. It can also be deployed on water (such as a ship, etc.). It can also be deployed in the air (such as an airplane, a balloon, a satellite, etc.). For example, the electronic device can be a terminal or a base station. For example, the terminal includes but is not limited to: a mobile phone, a tablet computer, a laptop computer, a handheld computer, a mobile internet device (MID), a wearable device (such as a smart watch, a smart bracelet, a pedometer, etc.), a vehicle-mounted device (such as a car, a bicycle, an electric vehicle, an airplane, a ship, a train, a high-speed train, etc.), a virtual reality (VR) device, an augmented reality (AR) device, a wireless terminal in industrial control, a smart home device (such as a refrigerator, a television, an air conditioner, an electric meter, etc.), a smart robot, a workshop device, a wireless terminal in self-driving, a wireless terminal in remote medical surgery, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, or a wireless terminal in a smart home, a flying device (such as a smart robot, a hot air balloon, a drone, an airplane), a radio frequency front-end module, etc.

[0057] Figure 1 It is a schematic structural diagram of the electronic device 1000 provided by an embodiment of the present application. As Figure 1 shown, the electronic device 1000 includes a filter 100 and a circuit board 200.

[0058] Refer to Figure 1, the filter 100 can be set on a circuit board 200.

[0059] For example, see Figure 1 The electronic device 1000 may further include a radio frequency module 300 , and the aforementioned filter 100 may be integrated into the radio frequency module 300 .

[0060] It is understandable that the filter 100 can also be independently provided as a component on the circuit board 200 .

[0061] The electronic device 1000 may further include a system on chip (SOC), a radio frequency chip, etc., which are arranged on the circuit board 200 .

[0062] The circuit board 200 is used to carry and electrically connect the system-on-chip (SoC), radio frequency (RF) chips, and the like. The RF chip may include components such as filters and processors. The processor processes various signals, and filters (including the filter 100) are an important part of RF signal processing, passing signals of specific frequencies while blocking signals of other frequencies.

[0063] For example, see Figure 1 , the electronic device 1000 may further include an antenna 500 .

[0064] For example, see Figure 1 , the antenna 500 can be coupled to the RF module 300.

[0065] It should be noted that the "coupling" here may mean that the RF module 300 and the antenna 500 are directly connected, or it may mean that the RF module 300 and the antenna 500 are indirectly connected, or it may mean that the RF module 300 and the antenna 500 have no contact but affect each other. The embodiment of the present application does not limit the specific coupling method of the RF module 300 and the antenna 500.

[0066] The antenna 500 is used to radiate the radio frequency signal transmitted in the radio frequency module 300 to the outside.

[0067] It can be understood that the electronic device 1000 may include one or more antennas 500 .

[0068] When the electronic device 1000 includes multiple antennas 500, one antenna 500 may correspond to one RF module 300, one antenna 500 may correspond to multiple RF modules 300, or multiple antennas 500 may share one RF module 300. The application scenarios in the relevant technologies are all applicable to the embodiments of the present application.

[0069] It is understandable that Figure 1The structure of the electronic device 1000 shown does not constitute a specific limitation on the electronic device 1000. The electronic device 1000 may include, for example, Figure 1 more or fewer components than those shown. For example, it may also include a packaging structure and auxiliary components (such as passive devices IPD or transmission lines) etc. (not shown in the figure), or it may combine some of the components as shown in Figure 1 or may arrange differently from the components shown in Figure 1 .

[0070] An embodiment of the present application also provides a radio frequency module 300. Exemplarily, referring to Figure 1 , the radio frequency module 300 can be applied to the above-mentioned electronic device 1000, for example, applied to the radio frequency chip in the electronic device 1000. Or, exemplarily, the radio frequency module 300 provided by the embodiment of the present application can also be used as a separate component alone, or can also be applied in other structures.

[0071] Referring to Figure 1 , the radio frequency module 300 may include a filter 100 and a power amplifier 400. Among them, the filter 100 is coupled to the power amplifier 400 to process and transmit radio frequency signals.

[0072] The power amplifier 400 is used to amplify the radio frequency signal, and the radio frequency module 300 transmits the amplified radio frequency signal to the antenna 500.

[0073] An embodiment of the present application also provides a filter 100.

[0074] Exemplarily, the filter 100 can be applied to the above-mentioned electronic device 1000, for example, applied to the radio frequency chip in the electronic device 1000.

[0075] Exemplarily, the filter 100 is not limited to being integrated in the electronic device 1000. The filter 100 can also be used as a separate component alone, or the filter 100 can be integrated with components such as the power amplifier 400 into a device (such as a radio frequency device, a radio frequency module 300, a surface acoustic wave filter module, etc.).

[0076] Exemplarily, the filter 100 provided by the embodiment of the present application can be, for example, a low-pass surface acoustic wave filter, a high-pass surface acoustic wave filter, a band-pass surface acoustic wave filter, a band-stop surface acoustic wave filter, an active surface acoustic wave filter, a surface acoustic wave temperature compensation filter, etc.

[0077] Figure 2 is a structural diagram of the filter 100 provided by the embodiment of the present application.

[0078] As shown in Figure 2As shown, the filter 100 may include a plurality of cascaded surface acoustic wave temperature-compensated resonators 10. These plurality of surface acoustic wave temperature-compensated resonators 10 may have different resonance frequencies and may be cascaded together in series and / or parallel. The performance of the filter 100 is closely related to the performance of the surface acoustic wave temperature-compensated resonators 10. Refer to Figure 2 When the plurality of surface acoustic wave temperature-compensated resonators 10 are cascaded together in series-parallel, Figure 2 the signal input terminal Vin, the signal output terminal Vout, and the ground terminal GND of the filter 100 are also shown.

[0079] The surface acoustic wave temperature-compensated resonator 10 is small in size and good in performance and is mostly used in various radio frequency terminal devices. The filter 100 formed by series-parallel connection of surface acoustic wave temperature-compensated resonators 10 with different resonance frequencies has advantages such as small passband insertion loss, high out-of-band steepness, and strong power tolerance.

[0080] In the related art, the surface acoustic wave temperature-compensated resonator 10 generates a large number of spurious modes, and the large number of spurious modes causes energy loss, which in turn causes the surface acoustic wave temperature-compensated resonator 10 to heat up. This not only reduces the performance of the surface acoustic wave temperature-compensated resonator 10 but also greatly reduces the service life of the surface acoustic wave temperature-compensated resonator 10.

[0081] Based on this, an embodiment of the present application provides a surface acoustic wave temperature-compensated resonator 10.

[0082] Figure 3 For Figure 2 is the structural diagram of the surface acoustic wave temperature-compensated resonator 10 in. Among them, in Figure 3 a coordinate system is established. The stacking direction of the piezoelectric substrate 110 and the cover layer 130 is the Z direction, the direction perpendicular to the paper surface is the X direction, the X direction is parallel to the piezoelectric substrate 110, and the direction perpendicular to the X direction is the Y direction.

[0083] Please refer to Figure 3 , the surface acoustic wave temperature-compensated resonator 10 includes a piezoelectric substrate 110, an interdigital transducer 120, and a cover layer 130. The interdigital transducer 120 is disposed on one surface of the piezoelectric substrate 110, the cover layer 130 covers the surface of the piezoelectric substrate 110 where the interdigital transducer 120 is disposed, and the interdigital transducer 120 is located between the cover layer 130 and the piezoelectric substrate 110; wherein, a plurality of grooves 131 arranged in an array are disposed on the surface of the cover layer 130 facing away from the piezoelectric substrate 110.

[0084] Among them, the piezoelectric substrate 110 can provide support for the interdigital transducer 120. The piezoelectric substrate 110 is used to excite surface acoustic waves under the action of the interdigital transducer 120. The material of the piezoelectric substrate 110 can include, for example, one or more of LiNbO3 (lithium niobate), LiTaO3 (lithium tantalate), quartz, etc.

[0085] The interdigital transducer 120 is made of a metal material. For example, the metal material can include, but is not limited to, at least one of metal materials such as Al (aluminum), Cu (copper), Pt (platinum), Mo (molybdenum), Ta (tantalum), Au (gold), or Ag (silver). Exemplarily, a layer of metal material can be deposited on the piezoelectric substrate 110, and then the metal material layer is etched to form the interdigital transducer 120.

[0086] Among them, the function of the piezoelectric substrate 110 is to generate the inverse piezoelectric effect by converting electrical energy into mechanical energy in the form of acoustic waves. For the surface acoustic wave temperature compensation resonator 10, the acoustic wave mainly propagates in the piezoelectric substrate 110.

[0087] The material of the interdigital transducer 120 can be, for example, one or more of Al (aluminum), Mo (molybdenum), W (tungsten), Ru (ruthenium), Cu (copper), and Pt (platinum).

[0088] Figure 4 For Figure 3 is a structural diagram of the interdigital transducer 120 in the first viewing angle V1.

[0089] Please refer to Figure 4 , the interdigital transducer 120 includes a relatively arranged first busbar 121 and a second busbar 122, a plurality of first electrode fingers (IDT electrode) 123, and a plurality of second electrode fingers 124; the first busbar 121 and the second busbar 122 are relatively arranged; the plurality of first electrode fingers 123 are connected to the first busbar 121, and are arranged in sequence along the extension direction of the first busbar 121, and protrude towards the second busbar 122; the plurality of second electrode fingers 124 are connected to the second busbar 122, and are arranged in sequence along the extension direction of the second busbar 122, and protrude towards the first busbar 121; among them, the first electrode fingers 123 and the second electrode fingers 124 are alternately arranged in sequence between the first busbar 121 and the second busbar 122, and the first electrode fingers 123 and the second electrode fingers 124 are spaced apart.

[0090] Among them, the extending directions of the first bus bar 121 and the second bus bar 122 can be the same, that is, the first bus bar 121 and the second bus bar 122 can be arranged in parallel. For example, both the first bus bar 121 and the second bus bar 122 extend along the X direction.

[0091] Exemplarily, the extending directions of the multiple first electrode fingers 123 can be the same. At this time, the multiple first electrode fingers 123 can be arranged in parallel.

[0092] Exemplarily, the extending directions of the multiple second electrode fingers 124 can be the same. At this time, the multiple second electrode fingers 124 can be arranged in parallel.

[0093] Among them, the first electrode finger 123 and the second electrode finger 124 can be arranged in parallel. For example, both the first electrode finger 123 and the second electrode finger 124 extend along the Y direction.

[0094] In some examples, the first electrode finger 123 can be perpendicular to the first bus bar 121, and the second electrode finger 124 can be perpendicular to the second bus bar 122.

[0095] The above "the multiple first electrode fingers 123 and the multiple second electrode fingers 124 are alternately arranged in sequence between the first bus bar 121 and the second bus bar 122" means that: between the first bus bar 121 and the second bus bar 122, one second electrode finger 124 is arranged between two adjacent first electrode fingers 123, and one first electrode finger 123 is arranged between two adjacent second electrode fingers 124. At this time, the arrangement pattern of the first electrode finger 123 and the second electrode finger 124 is: one first electrode finger 123, one second electrode finger 124, one first electrode finger 123, one second electrode finger 124, one first electrode finger 123, one second electrode finger 124, and so on are arranged in sequence.

[0096] For the number of the first electrode fingers 123 and the number of the second electrode fingers 124 in the interdigital transducer 120, there is no limitation and can be set according to needs. The multiple first electrode fingers 123 can be arranged at equal intervals or at unequal intervals. Similarly, the multiple second electrode fingers 124 can be arranged at equal intervals or at unequal intervals. Taking the first electrode fingers 123 as an example, the multiple first electrode fingers 123 being arranged at unequal intervals means that the distance between at least one pair of adjacent first electrode fingers 123 is different from the distance between another pair of adjacent first electrode fingers 123.

[0097] Furthermore, the spacing between any adjacent first electrode fingers 123 and second electrode fingers 124 is the same. In this case, among the plurality of first electrode fingers 123, some first electrode fingers 123 are provided with a second electrode finger 124 on either side of the first bus bar 121 in the extension direction, and the first electrode finger 123 is equidistant from the second electrode fingers 124 on either side.

[0098] Of course, the spacings between multiple adjacent pairs of first and second electrode fingers 123 and 124 may not be exactly the same, that is, the spacing between at least one pair of adjacent first and second electrode fingers 123 and 124 is different from the spacing between another pair of adjacent first and second electrode fingers 123 and 124.

[0099] It should be noted that the first bus bar 121, the first electrode finger 123, the second bus bar 122 and the second electrode finger 124 can be manufactured at the same time; or the first bus bar 121 and the first electrode finger 123 can be manufactured first, and then the second bus bar 122 and the second electrode finger 124 can be manufactured; or, the second bus bar 122 and the second electrode finger 124 can be manufactured first, and then the first bus bar 121 and the first electrode finger 123 can be manufactured.

[0100] In other examples, when preparing the IDT 120 , a layer of metal material may be deposited on the piezoelectric substrate 110 to form a metal film layer, and then the metal film layer may be etched to form the IDT 120 .

[0101] The material of the IDT 120 may be, for example, one or more of Al (aluminum), Mo (molybdenum), W (tungsten), Ru (ruthenium), Cu (copper) and Pt (platinum).

[0102] The cover layer 130 may cover the surfaces of the piezoelectric substrate 110 and the IDT 120 , thereby protecting the piezoelectric substrate 110 and the IDT 120 .

[0103] For example, the material of the capping layer 130 may include one or more of silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy), or aluminum oxide (Al2O3). For example, the capping layer 130 may include silicon dioxide (SiO2).

[0104] The plurality of grooves 131 may be arranged in an array, for example, the plurality of grooves 131 may be arranged in a row and a plurality of columns, and in this case, the plurality of grooves 131 may be arranged at equal intervals in the row direction.

[0105] For another example, multiple grooves 131 can be arranged in multiple rows and columns. At this time, the multiple rows of grooves can be arranged at equal intervals in the column direction, and the multiple grooves 131 in one row of grooves can be arranged at equal intervals in the row direction. Among them, the positions of the multiple grooves 131 in one column of grooves are the same in the column direction.

[0106] By providing multiple grooves 131 arranged in an array on a surface of the cover layer 130 facing away from the piezoelectric substrate 110, resonance formed between the surface of the cover layer 130 facing away from the piezoelectric substrate 110 and the interdigital transducer 120 can be reduced, thereby reducing the spurious modes formed between the surface of the cover layer 130 facing away from the piezoelectric substrate 110 and the interdigital transducer 120, and reducing the introduction of other spurious modes. Furthermore, the performance of the surface acoustic wave temperature compensation resonator 10 can be improved.

[0107] Figure 5 For Figure 3 the cross-sectional view at A-A', where, in Figure 5 only two pairs of adjacent first electrode fingers 123 and second electrode fingers 124 are schematically shown, and the remaining first electrode fingers 123 and the remaining second electrode fingers 124 are not shown in Figure 5 it.

[0108] In some embodiments, the groove 131 is strip-shaped and extends along the first direction F1. The multiple grooves 131 are arranged in a row. In a row of grooves, the multiple grooves 131 are arranged at equal intervals in the second direction F2. Among them, the first direction F1 and the second direction F2 are arranged crosswise and are both parallel to the piezoelectric substrate 110.

[0109] Exemplarily, the first direction F1 and the second direction F2 can be arranged perpendicularly.

[0110] Please refer back to Figure 3 , exemplarily, the distance between two adjacent grooves 131 is L1. At this time, the distance L1 between any two adjacent grooves 131 is equal.

[0111] Exemplarily, the width of the groove 131 in the second direction F2 is L2, and the widths L2 of the multiple grooves 131 in the second direction F2 can be equal.

[0112] Exemplarily, the lengths of the multiple grooves 131 in the first direction F1 can be equal.

[0113] Exemplarily, the groove 131 can include a first end and a second end arranged oppositely in the first direction F1. Among them, the first ends of the multiple grooves 131 are in the same position in the second direction F2. In other words, the first ends of the multiple grooves 131 are aligned in the second direction F2.

[0114] The second ends of the plurality of grooves 131 are in the same position in the second direction F2. In other words, the second ends of the plurality of grooves 131 are aligned in the second direction F2.

[0115] Among them, the plurality of grooves 131 are strip-shaped and are equally spaced along the second direction F2. Therefore, the plurality of grooves 131 are arranged periodically, which can reduce the stray modes formed between the surface of the cover layer 130 facing away from the piezoelectric substrate 110 and the interdigital transducer 120, and reduce the introduction of other stray modes, thereby improving the performance of the surface acoustic wave temperature compensation resonator 10. In addition, when preparing the plurality of periodically arranged grooves 131, the processing technology has simple process steps and low processing costs.

[0116] Please refer to Figure 5 , in some embodiments, the groove 131 penetrates the cover layer 130 along the first direction F1.

[0117] Among them, the cover layer 130 may include a first side surface 1301 and a second side surface 1302 that are oppositely arranged in the first direction F1. When the groove 131 penetrates the cover layer 130 along the first direction F1, the groove 131 may penetrate the first side surface 1301 and the second side surface 1302 along the first direction F1. At this time, the two ends of the groove 131 in the first direction F1 extend to the first side surface 1301 and the second side surface 1302 respectively.

[0118] Among them, by making the groove 131 penetrate the cover layer 130 along the first direction F1, the length of the groove 131 can be increased, and the lengths of the respective grooves 131 in the first direction F1 can be made the same, thereby improving the regularity of the arrangement of the plurality of grooves 131, reducing the stray modes formed between the surface of the cover layer 130 facing away from the piezoelectric substrate 110 and the interdigital transducer 120, and reducing the introduction of other stray modes, thereby improving the performance of the surface acoustic wave temperature compensation resonator 10.

[0119] Of course, in some other examples, the groove 131 may also penetrate one of the first side surface 1301 and the second side surface 1302 along the first direction F1. In some other examples, the groove 131 may not penetrate the first side surface 1301 and the second side surface 1302.

[0120] Please refer to Figure 3 and Figure 5 , in some embodiments, the first direction F1 is parallel to the extending direction of the first bus bar 121.

[0121] Exemplarily, the first bus bar 121 may extend along the X direction, and the first direction F1 may be parallel to the X direction.

[0122] Figure 6 is the admittance curve corresponding to the first resonator, Figure 7 is the admittance curve corresponding to the second resonator.

[0123] Among them, in the first resonator and the second resonator, the structures of the piezoelectric substrate 110 and the interdigital transducer 120 are the same. The difference between the first resonator and the second resonator is that there is no groove on the side of the covering layer facing away from the piezoelectric substrate 110 in the first resonator, while there are multiple grooves 131 on the side of the covering layer facing away from the piezoelectric substrate 110 in the second resonator. Among them, the grooves 131 are strip-shaped and extend along the X direction, and the multiple grooves 131 are arranged at equal intervals in sequence along the second direction F2.

[0124] In Figure 6 and Figure 7 , the abscissa represents frequency and the ordinate represents admittance.

[0125] As Figure 6 shown, the resonance frequency of the first resonator is approximately 0.602 GHz, and the anti-resonance frequency of the first resonator is approximately 0.629 GHz. From the Y admittance curve of the first resonator, it can be seen that there is a spurious mode near the anti-resonance point. For example, the spurious mode is located within the dashed box B. In Figure 6 , the shown spurious mode is generated near 595 MHz. For different resonator structures, the frequency or amplitude of the spurious mode may be different, but as long as it exists within the working frequency band, it will affect the performance of the resonator.

[0126] In addition, as Figure 6 shown, for the G admittance curve of the first resonator, after the resonance point, the curve fluctuates more and has a larger amplitude, which shows that the first resonator has more spurious modes.

[0127] As Figure 7 shown, the resonance frequency of the second resonator is approximately 0.589 GHz, and the anti-resonance frequency of the first resonator is approximately 0.611 GHz. From the Y admittance curve of the second resonator, it can be seen that near the anti-resonance point, for example, the spurious mode originally near 595 MHz has been suppressed smoothly. This can prove that by setting the grooves 131 on the surface of the covering layer 130 facing away from the piezoelectric substrate 110, the spurious modes generated in the surface acoustic wave temperature compensation resonator 10 can be reduced, thereby reducing the influence of the spurious modes on the performance of the surface acoustic wave temperature compensation resonator 10.

[0128] Please continue to refer to Figure 7 , compared with Figure 6, after the resonance point of the G admittance curve of the second resonator, the fluctuations of the curve are small and the amplitude is small. Thus, it can be proved that by providing the groove 131 on the surface of the cover layer 130 facing away from the piezoelectric substrate 110, the spurious modes generated in the surface acoustic wave temperature compensation resonator 10 can be reduced, and thus the influence of the spurious modes on the performance of the surface acoustic wave temperature compensation resonator 10 can be reduced.

[0129] Figure 8 For Figure 2 another structural diagram of the surface acoustic wave temperature compensation resonator 10 in Figure 9 For Figure 8 the structural diagram of the surface acoustic wave temperature compensation resonator 10 in Figure 9 from the third viewing angle V3. Among them, in Figure 9 only two pairs of adjacent first electrode fingers 123 and second electrode fingers 124 are shown schematically, and the remaining first electrode fingers 123 and the remaining second electrode fingers 124 are not shown in

[0130] Please refer to Figure 8 , in some other embodiments, the first direction F1 is parallel to the extending direction of the first electrode finger 123, that is, the extending direction of the groove 131 is parallel to the extending direction of the first electrode finger 123.

[0131] Exemplarily, the first electrode finger 123 can extend along the Y direction, and the first direction F1 can be parallel to the Y direction.

[0132] Please refer to Figure 9 , the second direction F2 can be parallel to the X direction, that is, a plurality of grooves 131 can be arranged at intervals along the X direction in sequence.

[0133] Figure 10 is the structural diagram of the surface of the cover layer 130 facing away from the piezoelectric substrate 110.

[0134] Please refer to Figure 10 , and at the same time in combination with Figure 4 , in some other embodiments, the first direction F1 intersects with the extending direction of the first bus bar 121 and intersects with the extending direction of the first electrode finger 123.

[0135] Among them, the first bus bar 121 can extend along the X direction, and the first electrode finger 123 can extend along the Y direction.

[0136] Among them, the bar-shaped groove 131 can extend along the extension direction of the first bus bar 121, or can extend along the extension direction of the first electrode finger 123, or the extension direction of the bar-shaped groove 131 can also intersect with the extension directions of both the first bus bar 121 and the first electrode finger 123. Therefore, the extension direction of the bar-shaped groove 131 can be designed according to the structure of the surface acoustic wave temperature compensation resonator 10.

[0137] In Figure 3 、 Figure 9 , the groove 131 can include a first groove side wall 1311 and a second groove side wall 1312 that are oppositely arranged in the second direction F2. In addition, the groove 131 can further include a groove bottom wall 1313. Among them, the first groove side wall 1311 and the second groove side wall 1312 can be respectively connected to two edges of the groove bottom wall 1313 that are oppositely arranged in the second direction F2.

[0138] Exemplarily, along the direction from the cover layer 130 to the piezoelectric substrate 110, the distance between the first groove side wall 1311 and the second groove side wall 1312 can remain unchanged. Or along the direction from the cover layer 130 to the piezoelectric substrate 110, the distance between the first groove side wall 1311 and the second groove side wall 1312 can gradually increase; or, along the direction from the cover layer 130 to the piezoelectric substrate 110, the distance between the first groove side wall 1311 and the second groove side wall 1312 can gradually decrease.

[0139] Among them, the first groove side wall 1311, the second groove side wall 1312, and the groove bottom wall 1313 can be planar or curved surfaces.

[0140] Figure 11 For Figure 2 is another structural diagram of the surface acoustic wave temperature compensation resonator 10 in Figure 11 In Figure 11 , only two pairs of adjacent first electrode fingers 123 and second electrode fingers 124 are schematically shown, and the remaining first electrode fingers 123 and the remaining second electrode fingers 124 are not shown in

[0141] Please refer to Figure 11 , in some other examples, the groove 131 can include a first groove side wall 1311 and a second groove side wall 1312 that are oppositely arranged in the second direction F2, and the edge of the first groove side wall 1311 far from the groove opening can be connected to the edge of the second groove side wall 1312 far from the groove opening. At this time, the cross-sectional shape of the groove 131 is approximately "V"-shaped.

[0142] It can be referred to Figure 3 、 Figure 5 、 Figure 8 、 Figure 9 and Figure 11, in some embodiments, the cover layer 130 includes a temperature compensation layer 132, the temperature compensation layer 132 covers the surface of the piezoelectric substrate 110 where the interdigital transducer 120 is disposed, and the interdigital transducer 120 is located between the temperature compensation layer 132 and the piezoelectric substrate 110, and the groove 131 is disposed on the surface of the temperature compensation layer 132 facing away from the piezoelectric substrate 110.

[0143] Exemplarily, the material of the temperature compensation layer 132 may include one or more of silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy), or aluminum oxide (Al2O3). For example, the temperature compensation layer 132 may include silicon dioxide (SiO2).

[0144] Among them, with the rapid evolution of 5G technology, the radio frequency front-end of terminal devices needs to support more and more frequency bands, and the crowded frequency bands put forward higher requirements for the performance of filters, such as smaller insertion loss, higher suppression ratio, better temperature characteristics, etc.

[0145] By disposing the temperature compensation layer 132 in the surface acoustic wave temperature compensation resonator 10, the surface acoustic wave temperature compensation resonator 10 can have a smaller TCF (Temperature coefficient of frequency), thereby reducing the performance deterioration of the surface acoustic wave temperature compensation resonator 10 in high-temperature and low-temperature environments.

[0146] Among them, the TCF and Q value of the surface acoustic wave temperature compensation resonator 10 can be adjusted by adjusting the thickness of the surface silicon dioxide layer.

[0147] Among them, by disposing the groove 131 on the temperature compensation layer 132, the structural complexity of the surface acoustic wave temperature compensation resonator 10 can be reduced, and the cost can be reduced.

[0148] Figure 12 For Figure 2 Another structural diagram of the surface acoustic wave temperature compensation resonator 10 in. Among them, in Figure 12 , only two pairs of adjacent first electrode fingers 123 and second electrode fingers 124 are schematically shown, and the remaining first electrode fingers 123 and the remaining second electrode fingers 124 are not shown in Figure 12 .

[0149] Please refer to Figure 12, the covering layer 130 includes a temperature compensation layer 132 and a dielectric layer 133. The temperature compensation layer 132 covers the surface of the piezoelectric substrate 110 where the interdigital transducer 120 is provided, and the interdigital transducer 120 is located between the temperature compensation layer 132 and the piezoelectric substrate 110. The dielectric layer 133 covers the surface of the temperature compensation layer 132 facing away from the piezoelectric substrate 110, and the groove 131 is provided on the surface of the dielectric layer 133 facing away from the piezoelectric substrate 110.

[0150] Exemplarily, the dielectric layer 133 may include at least one of Si and SiN. Of course, the dielectric layer 133 may also include other materials, which are not listed one by one here.

[0151] Among them, by providing the groove 131 on the dielectric layer 133, when the groove 131 is provided, there will be no loss to the temperature compensation layer 132, so as to ensure the TCF of the temperature compensation layer 132.

[0152] Please refer to ​ , in some embodiments, the surface acoustic wave temperature compensation resonator 10 may further include a first suppression portion 141, a second suppression portion 142, a third suppression portion 143, and a fourth suppression portion 144. Among them, the first suppression portion 141 is provided at one end of the first electrode finger 123 connected to the first bus bar 121, and the first suppression portion 141 may be spaced apart from the first bus bar 121. The second suppression portion 142 is provided at the end of the first electrode finger 123 away from the first bus bar 121.

[0153] The third suppression portion 143 is provided at one end of the second electrode finger 124 connected to the second bus bar 122, and the third suppression portion 143 may be spaced apart from the second bus bar 122. The fourth suppression portion 144 is provided at the end of the second electrode finger 124 away from the second bus bar 122.

[0154] Among them, the number of the first suppression portions 141 may be one or more. Exemplarily, the number of the first suppression portions 141 may be the same as the number of the first electrode fingers 123, and each first electrode finger 123 is provided with one first suppression portion 141.

[0155] The number of the second suppression portions 142 may be one or more. Exemplarily, the number of the second suppression portions 142 may be the same as the number of the first electrode fingers 123, and each first electrode finger 123 is provided with one second suppression portion 142.

[0156] Among them, the number of the third suppression portions 143 may be one or more. Exemplarily, the number of the third suppression portions 143 may be the same as the number of the second electrode fingers 123, and each second electrode finger 124 is provided with one third suppression portion 143.

[0157] The number of the fourth suppression parts 144 can be one or more. For example, the number of the fourth suppression parts 144 can be the same as the number of the second electrode fingers 124, and one fourth suppression part 144 is provided on each of the second electrode fingers 124.

[0158] Among them, when the surface acoustic wave temperature compensation resonator 10 generates acoustic waves, the acoustic waves can extend along the direction perpendicular to the first electrode finger 123. That is, the transverse wave can propagate along the extending direction of the first bus bar. However, there is scattering in the transmission of the transverse wave, and the transverse wave is scattered from the arrangement area of the first electrode finger 123 and the second electrode finger 124 to the area where the first bus bar 121 and the second bus bar 122 are located, which will further cause the generation of the transverse mode and lead to the performance degradation of the surface acoustic wave temperature compensation resonator 10.

[0159] In the embodiment of the present application, by providing the first suppression part 141, the mass of the area where the first suppression part 141 is located can be increased, so as to reduce the scattering of the acoustic wave to the first bus bar 121. Similarly, by providing the fourth suppression part 144, the scattering of the acoustic wave to the first bus bar 121 can be reduced. By providing the second suppression part 142 and the third suppression part 143, the scattering of the acoustic wave to the second bus bar 122 can be reduced. In summary, by providing the first suppression part 141, the second suppression part 142, the third suppression part 143 and the fourth suppression part 144, the scattering of the acoustic wave to the first bus bar 121 and the second bus bar 122 can be reduced, so as to reduce the generation of the transverse mode and improve the performance of the surface acoustic wave temperature compensation resonator 10.

[0160] As ​ shown, in some embodiments, when the resonant frequency of the surface acoustic wave temperature compensation resonator 10 is greater than or equal to 1.87 GHz and less than or equal to 1.93 GHz, the period length P of the groove 131 is greater than or equal to 500 nm and less than or equal to 1300 nm. At this time, the surface acoustic wave temperature compensation resonator 10 can have a better spurious suppression effect.

[0161] Among them, the period length P of the groove 131 is the sum of the width of the groove 131 in the second direction F2 and the distance between two adjacent grooves 131 in the second direction F2.

[0162] As ​ shown, the width of the groove 131 in the second direction F2 is L2, and the distance between two adjacent grooves 131 is L1. At this time, the period length P of the groove 131 = L1 + L2, and the duty cycle of the groove 131 = L2 / P.

[0163] Simulating and testing the third resonator, the fourth resonator, the fifth resonator, and the sixth resonator can obtain ​ .

[0164] ​ The admittance curves corresponding to the third resonator, the fourth resonator, the fifth resonator, and the sixth resonator.

[0165] Among them, in the third resonator, the fourth resonator, the fifth resonator, and the sixth resonator, the structures of the piezoelectric substrate 110 and the interdigital transducer 120 are the same. Among them, no groove 131 is provided on the surface of the covering layer 130 of the third resonator facing away from the piezoelectric substrate 110. In the fourth resonator, the fifth resonator, and the sixth resonator, the depth of the groove 131 is 0.05λ, and the duty cycle of the groove 131 is 0.5. The period length P of the groove 131 of the fourth resonator is equal to 519 nm, the period length P of the groove 131 of the fifth resonator is equal to 726 nm, and the period length P of the groove 131 of the sixth resonator is equal to 1210 nm. Among them, as ​ shown, λ is the sum of the distance L3 between two adjacent first electrode fingers 123 in the extension direction of the first bus bar 121 and the width L4 of the first electrode finger 123; the duty cycle of the groove 131 is the ratio of the width of the groove 131 in the second direction F2 to the period length P of the groove 131. As ​ shown, in some examples, for the convenience of narration, λ is defined as the period length of the electrode fingers, and a second electrode finger 124 is provided between two adjacent first electrode fingers 123. There is a gap between the adjacent first electrode finger 123 and the second electrode finger 124, and the gap distance is L5, and the width of the second electrode finger 124 is L6. Among them, the distance L3 between two adjacent first electrode fingers 123 in the extension direction of the first bus bar 121 = 2×L5 + L6, and the period length λ of the electrode fingers = L3 + L4.

[0166] In ​ , the abscissa represents the frequency, and the ordinate represents the admittance.

[0167] From ​ it can be seen that, compared with the third resonator, the Y admittance curves corresponding to the fourth resonator, the fifth resonator, and the sixth resonator are smoother near the anti-resonance point. This shows that when the resonance frequency of the surface acoustic wave temperature compensation resonator 10 is greater than or equal to 1.87 GHz and less than or equal to 1.93 GHz, by making 500 nm ≤ P ≤ 1300 nm, the spurious modes generated in the surface acoustic wave temperature compensation resonator 10 can be reduced, thereby reducing the influence of the spurious modes on the performance of the surface acoustic wave temperature compensation resonator 10.

[0168] Please continue to refer to​ Compared with the third resonator, for the G admittance curves corresponding to the fourth resonator, the fifth resonator, and the sixth resonator respectively, after the resonance point, the fluctuations of the curves are smaller and the amplitudes are smaller. This shows that when the resonance frequency of the surface acoustic wave temperature compensation resonator 10 is greater than or equal to 1.87 GHz and less than or equal to 1.93 GHz, by making 500 nm ≤ P ≤ 1300 nm, the spurious modes generated in the surface acoustic wave temperature compensation resonator 10 can be reduced, thereby reducing the influence of the spurious modes on the performance of the surface acoustic wave temperature compensation resonator 10.

[0169] Among them, when the resonance frequency of the surface acoustic wave temperature compensation resonator changes, the period length P of the groove 131 can also be adjusted accordingly.

[0170] In some embodiments, when the resonance frequency of the surface acoustic wave temperature compensation resonator 10 is greater than or equal to 0.57 GHz and less than or equal to 0.61 GHz, the depth Zd of the groove 131 is greater than or equal to 0.02P and less than or equal to 0.08P, that is, 0.02P ≤ Zd ≤ 0.08P. At this time, the surface acoustic wave temperature compensation resonator 10 can have a better spurious suppression effect.

[0171] ​ Are the admittance curve graphs corresponding to the seventh resonator, the eighth resonator, the ninth resonator, and the tenth resonator.

[0172] By performing simulation tests on the seventh resonator, the eighth resonator, the ninth resonator, and the tenth resonator, it can be obtained ​ Among them, in the seventh resonator, the eighth resonator, the ninth resonator, and the tenth resonator, the structures of the piezoelectric substrate 110 and the interdigital transducer 120 are the same. Among them, no groove 131 is provided on the surface of the covering layer 130 of the seventh resonator facing away from the piezoelectric substrate 110. In the eighth resonator, the ninth resonator, and the tenth resonator, the period length P of the groove 131 is equal to 0.5λ, the duty cycle of the groove 131 is 0.5, the depth of the groove 131 of the eighth resonator is equal to 0.03P, the depth of the groove 131 of the ninth resonator is equal to 0.05P, and the depth of the groove 131 of the tenth resonator is equal to 0.07P.

[0173] Please refer to ​ , the abscissa represents frequency and the ordinate represents admittance.

[0174] From ​It can be seen that, compared with the seventh resonator, the Y - admittance curves corresponding to the eighth resonator, the ninth resonator, and the tenth resonator are smoother near the anti - resonance point. This shows that when the resonance frequency of the surface acoustic wave temperature - compensated resonator is greater than or equal to 0.57 GHz and less than or equal to 0.61 GHz, by making the depth of the groove 131 greater than or equal to 0.02P and less than or equal to 0.08P, the spurious modes generated in the surface acoustic wave temperature - compensated resonator 10 can be reduced, thereby reducing the influence of the spurious modes on the performance of the surface acoustic wave temperature - compensated resonator 10.

[0175] Please continue to refer to ​ , compared with the seventh resonator, after the resonance point, the G - admittance curves corresponding to the eighth resonator, the ninth resonator, and the tenth resonator have smaller fluctuations and smaller amplitudes. This shows that when the resonance frequency of the surface acoustic wave temperature - compensated resonator is greater than or equal to 0.57 GHz and less than or equal to 0.61 GHz, by making the depth of the groove 131 greater than or equal to 0.02P and less than or equal to 0.08P, the spurious modes generated in the surface acoustic wave temperature - compensated resonator 10 can be reduced, thereby reducing the influence of the spurious modes on the performance of the surface acoustic wave temperature - compensated resonator 10.

[0176] Among them, when the resonance frequency of the surface acoustic wave temperature - compensated resonator 10 changes, the depth Zd of the groove 131 can also be adjusted accordingly.

[0177] In some embodiments, when the resonance frequency of the surface acoustic wave temperature - compensated resonator 10 is greater than or equal to 0.58 GHz and less than or equal to 0.61 GHz, the width L2 of the groove 131 in the second direction F2 is greater than or equal to 0.1P and less than or equal to 0.4P. At this time, the surface acoustic wave temperature - compensated resonator 10 can have a better spurious suppression effect.

[0178] ​ Are the admittance curve graphs corresponding to the eleventh resonator, the twelfth resonator, the thirteenth resonator, and the fourteenth resonator.

[0179] Performing simulation tests on the eleventh resonator, the twelfth resonator, the thirteenth resonator, and the fourteenth resonator, we can obtain ​Among the eleventh resonator, the twelfth resonator, the thirteenth resonator, and the fourteenth resonator, the structures of the piezoelectric substrate 110 and the interdigital transducer 120 are the same. Among them, no groove 131 is provided on the surface of the covering layer 130 of the eleventh resonator facing away from the piezoelectric substrate 110. In the twelfth resonator, the thirteenth resonator, and the fourteenth resonator, the depth of the groove 131 is 0.05λ, the period length P of the groove 131 is 0.5λ, the width L2 of the groove 131 of the twelfth resonator in the second direction F2 is equal to 0.125P, the width L2 of the groove 131 of the thirteenth resonator in the second direction F2 is equal to 0.25P, and the width L2 of the groove 131 of the fourteenth resonator in the second direction F2 is equal to 0.375P.

[0180] Please refer to ​ , the abscissa represents frequency, and the ordinate represents admittance.

[0181] It can be seen from ​ that, compared with the eleventh resonator, the Y admittance curves corresponding to the twelfth resonator, the thirteenth resonator, and the fourteenth resonator are smoother near the anti-resonance point. This shows that when the resonance frequency of the surface acoustic wave temperature compensation resonator is greater than or equal to 0.58 GHz and less than or equal to 0.61 GHz, by making the width L2 of the groove 131 in the second direction F2 greater than or equal to 0.1P and less than or equal to 0.4P, the spurious modes generated in the surface acoustic wave temperature compensation resonator 10 can be reduced, thereby reducing the influence of the spurious modes on the performance of the surface acoustic wave temperature compensation resonator 10.

[0182] Please continue to refer to ​ that, compared with the eleventh resonator, after the resonance point, the G admittance curves corresponding to the twelfth resonator, the thirteenth resonator, and the fourteenth resonator have smaller fluctuations and smaller amplitudes. This shows that when the resonance frequency of the surface acoustic wave temperature compensation resonator is greater than or equal to 0.58 GHz and less than or equal to 0.61 GHz, by making the width L2 of the groove 131 in the second direction F2 greater than or equal to 0.1P and less than or equal to 0.4P, the spurious modes generated in the surface acoustic wave temperature compensation resonator 10 can be reduced, thereby reducing the influence of the spurious modes on the performance of the surface acoustic wave temperature compensation resonator 10.

[0183] Among them, when the resonance frequency of the surface acoustic wave temperature compensation resonator 10 changes, the width L2 of the groove 131 in the second direction F2 can also be adjusted accordingly.

[0184] The embodiment of the present application also provides a method for manufacturing a surface acoustic wave temperature-compensated resonator. The method for manufacturing the surface acoustic wave temperature-compensated resonator can be used to manufacture the surface acoustic wave temperature-compensated resonator provided in some of the above embodiments.

[0185] ​ It is a flowchart of the method for manufacturing the surface acoustic wave temperature-compensated resonator provided in the embodiment of the present application.

[0186] Please refer to ​ , the method for manufacturing the surface acoustic wave temperature-compensated resonator may include the following steps S1-S3.

[0187] S1. Form an interdigital transducer on the piezoelectric substrate.

[0188] While referring to ​ , in combination with ​ , for example, in step S1, a metal material is deposited on the piezoelectric substrate 110 to form a metal film layer, and then the metal film layer is etched to form an interdigital transducer 120. The structure of the interdigital transducer 120 has been introduced in some of the above embodiments and will not be elaborated here.

[0189] For example, in step S1, when depositing the metal material, one or more of the processes such as atomic layer deposition (ALD), physical vapor deposition (PVD), and chemical vapor deposition (CVD) can be used to form the metal film layer.

[0190] S2. Form a covering layer on the surface of the piezoelectric substrate provided with the interdigital transducer, and the covering layer covers the surface of the interdigital transducer facing away from the piezoelectric substrate.

[0191] In step S2, one or more of the processes such as atomic layer deposition (ALD), physical vapor deposition (PVD), and chemical vapor deposition (CVD) can be used to form the covering layer.

[0192] S3. Form a plurality of grooves arranged in an array on the surface of the covering layer facing away from the piezoelectric substrate.

[0193] Among them, the groove 131 is formed on the surface of the covering layer 130 facing away from the piezoelectric substrate 110, so as to reduce the resonance generated between the surface of the covering layer 130 facing away from the piezoelectric substrate 110 and the interdigital transducer 120, and thus reduce the spurious modes formed between the surface of the covering layer 130 facing away from the piezoelectric substrate 110 and the interdigital transducer 120.

[0194] The preparation method provided by the embodiments of the present application is used to prepare the surface acoustic wave temperature compensation resonator provided by some of the above embodiments. Therefore, it has all the beneficial effects of the surface acoustic wave temperature compensation resonator provided by some of the above embodiments, which will not be elaborated here.

[0195] ​ It is another flowchart of the preparation method of the surface acoustic wave temperature compensation resonator provided by the embodiments of the present application.

[0196] Please refer to ​ and at the same time combine ​ , in some embodiments, the covering layer 130 includes a temperature compensation layer 132. At this time, the groove 131 can be formed on the temperature compensation layer 132.

[0197] Correspondingly, step S2 may include step S21, forming a temperature compensation layer on the surface of the piezoelectric substrate provided with the interdigital transducer, and the temperature compensation layer covers the surface of the interdigital transducer facing away from the piezoelectric substrate.

[0198] Step S3 may include step S31, forming a plurality of grooves arranged in an array on the surface of the temperature compensation layer facing away from the piezoelectric substrate.

[0199] Among them, by setting the temperature compensation layer 132 and forming the groove 131 on the temperature compensation layer 132, the structure of the surface acoustic wave temperature compensation resonator 10 can be simplified and the cost can be reduced.

[0200] Exemplarily, the temperature compensation layer 132 may include one or more of silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy), or aluminum oxide (Al2O3). For example, the covering layer 130 may include silicon dioxide (SiO2).

[0201] ​ It is another flowchart of the preparation method of the surface acoustic wave temperature compensation resonator provided by the embodiments of the present application.

[0202] Please refer to ​ and at the same time combine ​ , in some other embodiments, the covering layer 130 may include a temperature compensation layer 132 and a dielectric layer 133. At this time, the groove 131 can be formed on the dielectric layer 133.

[0203] Correspondingly, step S2 may include steps S22 and S23.

[0204] S22. Form a temperature compensation layer on the surface of the piezoelectric substrate where the interdigital transducer is provided, and the temperature compensation layer covers the surface of the interdigital transducer facing away from the piezoelectric substrate.

[0205] S23. Form a dielectric layer on the surface of the temperature compensation layer facing away from the piezoelectric substrate.

[0206] Step S3 may include step S32: Form a plurality of grooves arranged in an array on the surface of the dielectric layer facing away from the piezoelectric substrate.

[0207] Among them, the material of the dielectric layer 133 may be different from the material of the temperature compensation layer 132.

[0208] As described above, this is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed in the present application, thinking of changes or substitutions, should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A surface acoustic wave temperature compensation resonator, characterized in that: include: Piezoelectric substrate; an interdigital transducer, disposed on one surface of the piezoelectric substrate; A covering layer covers the surface of the piezoelectric substrate on which the interdigital transducer is provided, and the interdigital transducer is located between the covering layer and the piezoelectric substrate; wherein a plurality of array-arranged grooves are provided on the surface of the covering layer facing away from the piezoelectric substrate.

2. The surface acoustic wave temperature compensation resonator according to claim 1, characterized in that: The groove is strip-shaped and extends along a first direction; The plurality of grooves are arranged in a row. In the row of grooves, the plurality of grooves are arranged in sequence at equal intervals along the second direction, wherein the first direction and the second direction are arranged to intersect and are both parallel to the piezoelectric substrate.

3. The surface acoustic wave temperature compensation resonator according to claim 2, characterized in that: The groove penetrates the cover layer along the first direction.

4. The surface acoustic wave temperature compensation resonator according to claim 3, characterized in that: The IDT includes a first bus bar, a second bus bar, a plurality of first electrode fingers, and a plurality of second electrode fingers, wherein the first bus bar and the second bus bar are arranged opposite to each other; the plurality of first electrode fingers are connected to the first bus bar, and are sequentially arranged along the extension direction of the first bus bar and protrude toward the second bus bar; the plurality of second electrode fingers are connected to the second bus bar, and are sequentially arranged along the extension direction of the second bus bar and protrude toward the first bus bar; wherein the first electrode fingers and the second electrode fingers are alternately arranged between the first bus bar and the second bus bar, and the first electrode fingers and the second electrode fingers are spaced apart; Wherein, the first direction is parallel to the extending direction of the first bus bar; or, The first direction is parallel to the extending direction of the first electrode fingers; or, The first direction intersects with an extending direction of the first bus bar and an extending direction of the first electrode fingers.

5. The surface acoustic wave temperature compensation resonator according to claim 4, characterized in that: When the resonant frequency of the surface acoustic wave temperature compensation resonator is greater than or equal to 1.87 GHz and less than or equal to 1.93 GHz, the period length of the groove is greater than or equal to 500 nm and less than or equal to 1300 nm; The period length of the groove is the sum of the width of the groove in the second direction and the distance between two adjacent grooves in the second direction.

6. The surface acoustic wave temperature compensation resonator according to claim 4, characterized in that: When the resonant frequency of the surface acoustic wave temperature compensation resonator is greater than or equal to 0.57 GHz and less than or equal to 0.61 GHz, the depth of the groove is greater than or equal to 0.02P and less than or equal to 0.08P; Wherein, P is the period length of the groove, and the period length of the groove is equal to the sum of the width of the groove in the second direction and the distance between two adjacent grooves in the second direction.

7. The surface acoustic wave temperature compensation resonator according to claim 4, characterized in that: When the resonant frequency of the surface acoustic wave temperature compensation resonator is greater than or equal to 0.58 GHz and less than or equal to 0.61 GHz, the width of the groove in the second direction is greater than or equal to 0.1P and less than or equal to 0.4P; Wherein, P is the period length of the groove, and the period length of the groove is equal to the sum of the width of the groove in the second direction and the distance between two adjacent grooves in the second direction.

8. The surface acoustic wave temperature compensation resonator according to any one of claims 1 to 7, characterized in that: The covering layer includes a temperature compensation layer, which covers the surface of the piezoelectric substrate on which the interdigital transducer is provided, and the interdigital transducer is located between the temperature compensation layer and the piezoelectric substrate, and the groove is provided on the surface of the temperature compensation layer facing away from the piezoelectric substrate.

9. The surface acoustic wave temperature compensation resonator according to any one of claims 1 to 7, characterized in that: The covering layer includes a temperature compensation layer and a dielectric layer. The temperature compensation layer covers the surface of the piezoelectric substrate on which the interdigital transducer is provided, and the interdigital transducer is located between the temperature compensation layer and the piezoelectric substrate. The dielectric layer covers the surface of the temperature compensation layer facing away from the piezoelectric substrate, and the groove is provided on the surface of the dielectric layer facing away from the piezoelectric substrate.

10. A filter, characterized in that: The invention comprises a plurality of cascaded surface acoustic wave temperature compensation resonators; wherein the surface acoustic wave temperature compensation resonator is the surface acoustic wave temperature compensation resonator according to any one of claims 1 to 9.

11. An electronic device, characterized in that: It includes a filter and a circuit board, wherein the filter and the processor are both arranged on the circuit board; Wherein, the filter is the filter according to claim 10.

12. A method for preparing a surface acoustic wave temperature compensation resonator, characterized in that: forming an interdigital transducer on the piezoelectric substrate; forming a covering layer on the surface of the piezoelectric substrate on which the IDT is provided, wherein the covering layer covers the surface of the IDT facing away from the piezoelectric substrate; A plurality of grooves arranged in an array are formed on a surface of the cover layer facing away from the piezoelectric substrate.

13. The preparation method according to claim 12, characterized in that It is characterized by: The method comprises forming a covering layer on a surface of the piezoelectric substrate on which the interdigital transducer is provided, wherein the covering layer covers a surface of the interdigital transducer facing away from the piezoelectric substrate, comprising: forming a temperature compensation layer on the surface of the piezoelectric substrate on which the interdigital transducer is provided, and the temperature compensation layer covers the surface of the interdigital transducer facing away from the piezoelectric substrate; The step of forming a plurality of grooves arranged in an array on a surface of the cover layer facing away from the piezoelectric substrate comprises: A plurality of grooves arranged in an array are formed on a surface of the temperature compensation layer facing away from the piezoelectric substrate.

14. The preparation method according to claim 12, characterized in that It is characterized by: The method comprises forming a covering layer on a surface of the piezoelectric substrate on which the interdigital transducer is provided, wherein the covering layer covers a surface of the interdigital transducer facing away from the piezoelectric substrate, comprising: forming a temperature compensation layer on the surface of the piezoelectric substrate on which the interdigital transducer is provided, and the temperature compensation layer covers the surface of the interdigital transducer facing away from the piezoelectric substrate; forming a dielectric layer on a surface of the temperature compensation layer facing away from the piezoelectric substrate; A plurality of grooves arranged in an array are formed on a surface of the cover layer facing away from the piezoelectric substrate, comprising: A plurality of grooves arranged in an array are formed on a surface of the dielectric layer facing away from the piezoelectric substrate.

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