Surface acoustic wave resonator and electronic device

Abstract

The utility model discloses a surface acoustic wave resonator and electronic equipment, and belongs to the technical field of surface acoustic wave devices. The surface acoustic wave resonator includes: a piezoelectric layer; the interdigital transducer is arranged on one side of the piezoelectric layer, the interdigital transducer comprises two interdigital electrodes which are oppositely arranged in the first direction, each interdigital electrode comprises a bus bar and a first interdigital which is connected with the bus bar and extends in the first direction, and each first interdigital comprises a first part and a second part; the first portion is located at the joint of the first interdigital and the bus bar, the width of the first portion in the second direction intersecting with the first direction is larger than that of the second portion in the second direction, a gap is formed between the second portion on one interdigital electrode and the bus bar on the other interdigital electrode, and the width of the gap in the first direction is smaller than a first distance; and the first metal belt structure is arranged on the surface, deviating from the piezoelectric layer, of the interdigital transducer, and the first metal belt structure is located at the position, close to the first interdigital, of the bus bar.

Description

Technical Field

[0001] The present application belongs to the technical field of surface acoustic wave devices, and in particular relates to a surface acoustic wave resonator and an electronic device. Background Art

[0002] Surface acoustic wave (SAW) resonators are widely used in communication devices such as radio frequency (RF) filters, duplexers, delay lines, frequency discriminators, and modulators. For example, RF filters enable efficient and synchronized wireless communication across multiple frequency bands and devices. A SAW resonator primarily consists of a piezoelectric structure and an electrode structure on its surface. Utilizing the piezoelectric effect of the piezoelectric structure, SAW is generated and propagated as the primary mode within the electrode structure.

[0003] However, during the propagation of surface acoustic waves, due to the characteristics of piezoelectric materials and electrode structures, transverse mode acoustic waves perpendicular to the main mode surface acoustic wave may be excited. The existence of such transverse mode acoustic waves will affect the performance of the surface acoustic wave resonator. Utility Model Content

[0004] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a surface acoustic wave resonator and electronic device that can adjust the acoustic impedance near the connection between the bus bar and the first interdigital finger, thereby ensuring uniform propagation of surface acoustic waves, reducing transverse stray waves, and improving the performance of the surface acoustic wave resonator.

[0005] In a first aspect, the present application provides a surface acoustic wave resonator, comprising:

[0006] Piezoelectric layer;

[0007] An interdigital transducer, the interdigital transducer being disposed on one side of the piezoelectric layer, the interdigital transducer comprising two interdigital electrodes arranged opposite each other along a first direction, each of the interdigital electrodes comprising a bus bar and a first finger connected to the bus bar and extending along the first direction, the first finger comprising a first portion and a second portion, the first portion being located at a connection between the first finger and the bus bar, the width of the first portion along a second direction intersecting the first direction being greater than the width of the second portion along the second direction, a gap being defined between the second portion on one of the interdigital electrodes and the bus bar on the other interdigital electrode, the width of the gap along the first direction being less than the first distance;

[0008] A first metal strip structure is provided on a side of the IDT facing away from the piezoelectric layer, and the first metal strip structure is located on the bus bar near the first interdigital finger.

[0009] According to the surface acoustic wave resonator of the present application, the width of the first part of the connection between the first finger and the bus bar along the propagation direction of the surface acoustic wave is greater than the width of the second part of the first finger along the propagation direction of the surface acoustic wave, and the width of the gap between the second part on one fork finger electrode and the bus bar on the other fork finger electrode along the direction intersecting with the propagation direction of the surface acoustic wave is less than the first distance, and a first metal strip structure is arranged at a position near the first fork finger on the bus bar, which can adjust the acoustic impedance near the connection between the bus bar and the first fork finger, thereby ensuring uniform propagation of the surface acoustic wave, reducing lateral stray waves, and improving the performance of the surface acoustic wave resonator.

[0010] According to one embodiment of the present application, the first metal strip structure is a continuous strip structure extending along the second direction.

[0011] According to one embodiment of the present application, the first metal strip structure extends along the first direction in an interdigitated region to form a first additional metal element, and the interdigitated region is a region extending along the first direction corresponding to the first fingers.

[0012] According to one embodiment of the present application, the first additional metal element extends along at least one of a positive direction and a reverse direction of the first direction.

[0013] According to one embodiment of the present application, the first metal strip structure is a block structure, and the first metal strip structure is provided in an interdigital region, and the interdigital region is a region corresponding to the first interdigit and extending along the first direction.

[0014] According to one embodiment of the present application, the first metal strip structure includes at least two first metal strips, wherein the first metal strips extend along the second direction, and the at least two first metal strips are spaced apart along the first direction.

[0015] According to one embodiment of the present application, the surface acoustic wave resonator further includes:

[0016] A second additional metal element is provided on a surface of the first portion facing away from the piezoelectric layer.

[0017] According to one embodiment of the present application, the surface acoustic wave resonator further includes:

[0018] A second metal strip structure, wherein the second metal strip structure is arranged on a side of the interdigital transducer away from the piezoelectric layer, the second metal strip structure is located on the bus bar at a position away from the first interdigital transducer, and the spacing between the second metal strip structure and the first metal strip structure along the first direction is a first target distance.

[0019] According to one embodiment of the present application, a projection of an edge of the first metal strip structure close to the first finger on the piezoelectric layer is located at a projection of the gap on the piezoelectric layer.

[0020] According to one embodiment of the present application, the first metal strip structure is filled in the gap, or an insulating layer is provided between the first metal strip structure and the piezoelectric layer in the gap region.

[0021] In a second aspect, the present application provides an electronic device, the electronic device comprising:

[0022] The surface acoustic wave resonator as described in the first aspect.

[0023] According to the electronic device of the present application, the width of the first part of the connection between the first finger and the bus bar along the propagation direction of the surface acoustic wave is greater than the width of the second part of the first finger along the propagation direction of the surface acoustic wave, and the gap between the second part on one finger electrode and the bus bar on the other finger electrode has a width less than the first distance along the direction intersecting with the propagation direction of the surface acoustic wave, and a first metal strip structure is arranged at a position near the first finger on the bus bar, which can adjust the acoustic impedance near the connection between the bus bar and the first finger, thereby ensuring uniform propagation of the surface acoustic wave, reducing lateral stray waves, and improving the performance of the surface acoustic wave resonator.

[0024] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0026] Figure 1 This is one of the structural diagrams of the surface acoustic wave resonator provided in the embodiment of the present application;

[0027] Figure 2 This is the second structural diagram of the surface acoustic wave resonator provided in an embodiment of the present application;

[0028] Figure 3 This is the third structural diagram of the surface acoustic wave resonator provided in the embodiment of the present application;

[0029] Figure 4 This is the fourth structural diagram of the surface acoustic wave resonator provided in an embodiment of the present application;

[0030] Figure 5 This is the fifth structural diagram of the surface acoustic wave resonator provided in the embodiment of the present application;

[0031] Figure 6This is the sixth structural diagram of the surface acoustic wave resonator provided in the embodiment of the present application;

[0032] Figure 7 This is the seventh structural diagram of the surface acoustic wave resonator provided in the embodiment of the present application;

[0033] Figure 8 This is the eighth structural diagram of the surface acoustic wave resonator provided in the embodiment of the present application;

[0034] Figure 9 This is the ninth structural diagram of the surface acoustic wave resonator provided in the embodiment of the present application;

[0035] Figure 10 This is the tenth structural diagram of the surface acoustic wave resonator provided in an embodiment of the present application;

[0036] Figure 11 This is one of the schematic diagrams of the admittance-frequency relationship of the surface acoustic wave resonator provided in the embodiment of the present application;

[0037] Figure 12 This is the second schematic diagram of the admittance-frequency relationship of the surface acoustic wave resonator provided in an embodiment of the present application;

[0038] Figure 13 This is the third schematic diagram of the admittance-frequency relationship of the surface acoustic wave resonator provided in an embodiment of the present application;

[0039] Figure 14 This is the fourth schematic diagram of the admittance-frequency relationship of the surface acoustic wave resonator provided in an embodiment of the present application;

[0040] Figure 15 This is one of the schematic diagrams comparing the results of the surface acoustic wave resonator of the embodiment of the present application with the surface acoustic wave resonator in the related art;

[0041] Figure 16 This is the second schematic diagram comparing the results of the surface acoustic wave resonator of the embodiment of the present application with the surface acoustic wave resonator in the related art.

[0042] Reference numerals:

[0043] Base layer 110, intermediate layer 120, piezoelectric layer 130, bus bar 151, first portion 152, second portion 153,

[0044] Gap 154, first metal strip structure 155, second metal strip structure 210, first additional metal element 410,

[0045] Interdigitated region 420 , first metal strip 155 a , second additional metal element 810 , insulating layer 1010 . DETAILED DESCRIPTION

[0046] The following describes in detail embodiments of the present application. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application.

[0047] Reference below Figures 1-16 A surface acoustic wave resonator and an electronic device according to embodiments of the present application are described.

[0048] like Figure 1 As shown, the surface acoustic wave resonator of the embodiment of the present application includes:

[0049] The piezoelectric layer 130 and the IDT are provided on one side of the piezoelectric layer 130 .

[0050] Among them, the piezoelectric (PE) layer is a layer structure with a piezoelectric effect, that is, the piezoelectric layer 130 can generate electric charge when subjected to mechanical stress, or produce deformation under the action of an electric field. The piezoelectric layer 130 can be made of piezoelectric materials, such as quartz, zinc aluminate (ZnO) and lithium tantalate (LT).

[0051] The interdigital transducer (IDT) is provided on the surface of the piezoelectric layer 130. The IDT can convert the electrical signal into a surface acoustic wave (SAW) through the piezoelectric effect of the piezoelectric layer 130, and can convert the SAW back into an electrical signal. The material of the IDT can be metal, for example, aluminum (AL).

[0052] like Figure 1 As shown, the surface acoustic wave resonator of the embodiment of the present application may also include an intermediate layer 120 and a base layer 110, wherein the intermediate layer 120 may be a silicon oxide (SiO2) material, and the base layer 110 may be a silicon (Si) material. The intermediate layer 120 and the base layer 110 are arranged at the bottom of the piezoelectric layer 130 to provide support for the entire surface acoustic wave resonator.

[0053] In this embodiment, the IDT includes two interdigital electrodes arranged opposite to each other along a first direction. Each of the interdigital electrodes includes a bus bar 151 and first fingers connected to the bus bar 151 and extending along the first direction.

[0054] The first direction may be any direction parallel to the surface of the piezoelectric layer 130 .

[0055] It should be noted that Figure 1FIG shows an interdigital electrode in an interdigital transducer and a first interdigital electrode of another interdigital electrode. The first direction can be Figure 1 Y direction shown in .

[0056] In this embodiment, Figure 1 As shown, each interdigital electrode includes a bus bar 151 and a first interdigital finger connected to the bus bar 151 and extending along a first direction.

[0057] It should be noted that the interdigital electrode may include a plurality of first fingers, and the number of first fingers on the two interdigital electrodes may be the same.

[0058] The bus bar 151 is a structure that connects a plurality of interdigitated fingers and realizes current collection, and the first interdigitated finger is a structure that realizes conversion between an electrical signal and a surface acoustic wave.

[0059] In this embodiment, Figure 1 As shown, the first finger includes a first portion 152 and a second portion 153 . The first portion 152 is located at the connection between the first finger and the bus bar 151 . The width of the first portion 152 along a second direction intersecting the first direction is greater than the width of the second portion 153 along the second direction.

[0060] The first part 152 of the first fork finger is connected to the bus bar 151, and the first part 152 of the first fork finger is connected to the second part 153 on the side away from the bus bar 151. The first part 152 and the second part 153 can be an integrated structure without a gap 154, and the width of the first part 152 along the second direction is greater than the width of the second part 153 along the second direction.

[0061] The second direction can be Figure 1 The X direction is shown in FIG, and the second direction may be the direction in which the surface acoustic wave propagates.

[0062] In this embodiment, a gap 154 is provided between the second portion 153 on one interdigital electrode and the bus bar 151 on another interdigital electrode. The width of the gap 154 along the first direction is smaller than the first distance.

[0063] The two interdigitated electrodes are arranged opposite to each other along the first direction, and the second part 153 of one interdigitated electrode is close to the bus bar 151 of the other interdigitated electrode. There is a gap 154 with a very small width between the second part 153 and the bus bar 151 that are close to each other, that is, the width of the gap 154 along the first direction is less than the first distance.

[0064] In this embodiment, the first distance may be set to 0.1 surface acoustic wave wavelength to 0.5 surface acoustic wave wavelength.

[0065] It can be understood that the first distance is a value corresponding to the preset width of the gap 154 along the first direction. When the width of the gap 154 along the first direction is smaller than the first distance, the surface acoustic wave resonator is a surface acoustic wave resonator with a narrow gap 154.

[0066] In this embodiment, Figure 1 As shown, the surface acoustic wave resonator further includes a first metal strip structure 155 , which is provided on a side of the IDT facing away from the piezoelectric layer 130 , and is located on the bus bar 151 near the first interdigital finger.

[0067] The first metal strip structure 155 may be made of a metal material, for example, may be made of copper (Cu).

[0068] In this embodiment, a first metal strip structure 155 is provided on a side of the bus bar 151 facing away from the piezoelectric layer 130 and close to the first interdigital finger. The first metal strip structure 155 extends along the second direction and may be a strip-shaped structure.

[0069] In this embodiment, the material of the first metal strip structure 155 may be the same as the material of the bus bar 151 , or the material of the first metal strip structure 155 may be different from the material of the bus bar 151 .

[0070] In this embodiment, the first metal strip structure 155 may also be formed using a dielectric material, such as tantalum pentoxide (Ta 2 O 5 ), aluminum oxide (Al 2 O 3 ), hafnium dioxide (HfO 2 ), etc.

[0071] The length of the first metal tape structure 155 along the first direction may be less than the length of the bus bar 151 along the first direction, and the length of the first metal tape structure 155 along the second direction may be less than or equal to the length of the bus bar 151 along the second direction.

[0072] In this embodiment, the first metal strip structure 155 can improve the energy concentration of the surface acoustic wave, ensuring that most of the energy propagates along the main mode, that is, along the second direction, and can reduce the transversal mode (TM) acoustic wave leaking to the bus bar 151.

[0073] According to the surface acoustic wave resonator provided by the embodiment of the present application, the width of the first portion 152 at the connection between the first finger and the bus bar 151 along the propagation direction of the surface acoustic wave is greater than the width of the second portion 153 of the first finger along the propagation direction of the surface acoustic wave, and the width of the gap 154 between the second portion 153 on one interdigital electrode and the bus bar 151 on the other interdigital electrode along the direction intersecting with the propagation direction of the surface acoustic wave is less than the first distance, and a first metal strip structure 155 is provided at a position near the first interdigital finger on the bus bar 151, which can adjust the acoustic impedance near the connection between the bus bar 151 and the first interdigital finger, thereby ensuring uniform propagation of the surface acoustic wave, reducing lateral stray waves, and improving the performance of the surface acoustic wave resonator.

[0074] In some embodiments, the first metal strip structure 155 is a continuous strip structure extending along the second direction.

[0075] In this embodiment, a strip-shaped first metal strip structure 155 may be provided along the second direction on a side of the bus bar 151 facing away from the piezoelectric layer 130 and close to the first interdigitated finger.

[0076] The length of the first metal strip structure 155 along the first direction may be less than the length of the bus bar 151 along the first direction, and the length of the first metal strip structure 155 along the second direction may be less than or equal to the length of the bus bar 151 along the second direction.

[0077] In some embodiments, the first metal tape structure 155 extends along a first direction in the interdigitated region 420 to form a first additional metal element 410 .

[0078] The interdigital region 420 is a region corresponding to the first interdigital region and extending along the first direction.

[0079] In this embodiment, the interdigital region 420 may be a region extending along the first direction corresponding to the first portion 152 of the first interdigit.

[0080] It can be understood that the interdigital region 420 includes a region extending along the first direction corresponding to a first finger of the interdigital electrode and a region extending along the first direction corresponding to a first finger of another interdigital electrode.

[0081] In this embodiment, the first additional metal element 410 may be a structure grown on the first metal strip structure 155 , and the first additional metal element 410 and the first metal strip structure 155 are connected as one body.

[0082] In this embodiment, the first metal strip structure 155 may extend along the first direction in a region extending along the first direction corresponding to the first interdigital electrode, forming a first additional metal element 410 ;

[0083] The first metal strip structure 155 may also extend along the first direction to form a first additional metal element 410 in a region extending along the first direction corresponding to a first interdigital finger of another interdigital electrode;

[0084] The first metal strip structure 155 may also extend along the first direction to form a first additional metal element 410 in a region extending along the first direction corresponding to the first finger of the interdigital electrode and in a region extending along the first direction corresponding to the first finger of the other interdigital electrode.

[0085] It should be noted that the sizes of the first additional metal elements 410 formed by the first metal strip structure 155 may be different, and the shapes of the first additional metal elements 410 may be different.

[0086] In this embodiment, the first additional metal element 410 may extend to the surface of the first interdigital finger, and the length of the first additional metal element 410 along the second direction may be smaller than the length of the interdigital region 420 along the second direction.

[0087] In some embodiments, the first additional metal element 410 extends in at least one of a positive direction and a negative direction of the first direction.

[0088] In this embodiment, the first additional metal element 410 may extend in the positive direction of the first direction, the first additional metal element 410 may extend in the negative direction of the first direction, or the first additional metal element 410 may extend in both the positive and negative directions of the first direction.

[0089] In this embodiment, the shapes and sizes of the first additional metal element 410 extending in the forward direction and the reverse direction along the first direction may be different.

[0090] The forward direction may be any direction in the first direction, and the reverse direction may be a direction in the first direction opposite to the forward direction.

[0091] For example, the forward direction may be a direction close to one end of the first interdigital finger in the first direction, and the reverse direction may be a direction away from one end of the first interdigital finger in the first direction.

[0092] In this embodiment, the first additional metal element 410 extends along the first direction toward one end of the first interdigital finger, and may extend to the surface of the first interdigital finger.

[0093] like Figure 4 As shown, the first additional metal element 410 extends along the first direction toward one end away from the first fork; Figure 5 As shown, the first additional metal element 410 extends along the first direction, simultaneously toward an end away from the first interdigital finger and an end close to the first interdigital finger.

[0094] In some embodiments, the first metal strip structure 155 is a block structure, and the first metal strip structure 155 is disposed in the interdigitated region 420 .

[0095] The interdigital region 420 is a region corresponding to the first interdigital region and extending along the first direction.

[0096] It can be understood that the interdigital region 420 includes a region extending along the first direction corresponding to a first finger of the interdigital electrode and a region extending along the first direction corresponding to a first finger of another interdigital electrode.

[0097] In this embodiment, the block-shaped first metal strip structure 155 may be disposed in the interdigital region 420 corresponding to the interdigital electrode, or the block-shaped first metal strip structure 155 may be disposed in the interdigital region 420 corresponding to another interdigital electrode.

[0098] like Figure 6 As shown, the block-shaped first metal strip structure 155 is disposed in the interdigital region 420 corresponding to the interdigital electrode.

[0099] In some embodiments, the first metal strip structure 155 includes at least two first metal strips 155 a . The first metal strips 155 a extend along the second direction, and the at least two first metal strips 155 a are spaced apart along the first direction.

[0100] In this embodiment, in the first metal strip structure 155 , the shape and size of each first metal strip 155 a may be the same or different, and the first metal strip 155 a may be a strip-shaped structure.

[0101] In this embodiment, each first metal strip 155 a extends along the second direction, the first metal strips 155 a are not connected to each other, and the first metal strips 155 a are arranged at intervals along the first direction.

[0102] like Figure 7 As shown, the first metal strip structure 155 includes two first metal strips 155 a . The two first metal strips 155 a extend along the second direction, and the two first metal strips 155 a are spaced apart along the first direction.

[0103] In some embodiments, the surface acoustic wave resonator further includes a second additional metal element 810 . The second additional metal element 810 is disposed on a surface of the first portion 152 facing away from the piezoelectric layer 130 .

[0104] In this embodiment, the material of the second additional metal element 810 may be the same as that of the first metal strip structure 155 . The second additional metal element 810 may be a block-shaped structure, and a gap may exist between the second additional metal element 810 and the first metal strip structure 155 .

[0105] like Figure 8As shown, a first metal strip structure 155 and a second additional metal element 810 are arranged on the side of the interdigital transducer facing away from the piezoelectric layer 130. The first metal strip structure 155 is arranged on the bus bar 151 near the first interdigital finger, and the second additional metal element 810 is arranged on the first part 152. There is a gap between the first metal strip structure 155 and the second additional metal element 810.

[0106] It should be noted that the second additional metal element 810 may be provided on the first portion 152 without providing the first metal strip structure 155 .

[0107] In some embodiments, the SAW resonator further includes a second metal strip structure 210 . The second metal strip structure 210 is disposed on a side of the IDT facing away from the piezoelectric layer 130 .

[0108] The second metal strip structure 210 is located on the bus bar 151 away from the first interdigitated finger. The distance between the second metal strip structure 210 and the first metal strip structure 155 along the first direction is a first target distance.

[0109] In this embodiment, the second metal tape structure 210 may be disposed on the edge of the bus bar 151 away from the first fingers, with a gap between the second metal tape structure 210 and the first metal tape structure 155 .

[0110] The distance between the second metal strip structure 210 and the first metal strip structure 155 along the first direction may be at least one surface acoustic wave wavelength, that is, the first target distance is at least one surface acoustic wave wavelength.

[0111] In this embodiment, the material of the second metal tape structure 210 and the material of the first metal tape structure 155 may be the same or different, and the thickness of the second metal tape structure 210 may be greater than that of the first metal tape structure 155 .

[0112] like Figure 2 and Figure 3 As shown, the second metal strip structure 210 is provided on the edge of the bus bar 151 away from the first interdigital finger. There is a gap between the second metal strip structure 210 and the first metal strip structure 155 . The thickness of the second metal strip structure 210 is greater than that of the first metal strip structure 155 .

[0113] In some embodiments, the first metal strip structure 155 is located near a projection of an edge of the first finger on the piezoelectric layer 130 and is located at a projection of the gap 154 on the piezoelectric layer 130 .

[0114] In this embodiment, the first metal strip structure 155 extends toward the gap 154 along the first direction in a region corresponding to the extension of the gap 154 along the first direction, and extends to the region where the gap 154 is located.

[0115] The portion of the first metal strip structure 155 close to the edge of the first finger, ie, the projection of the portion of the first metal strip structure 155 extending beyond the bus bar 151 on the piezoelectric layer 130 , is located at the projection of the gap 154 on the piezoelectric layer 130 .

[0116] In this embodiment, the length of the projection of the edge of the first metal strip structure 155 close to the first interdigital finger on the piezoelectric layer 130 along the first direction may be smaller than the length of the projection of the gap 154 on the piezoelectric layer 130 along the first direction.

[0117] In some embodiments, the first metal strip structure 155 fills the gap 154 , or an insulating layer 1010 is provided between the first metal strip structure 155 and the piezoelectric layer 130 in the gap region.

[0118] In this embodiment, the first metal strip structure 155 extends to the area where the gap 154 is located. The first metal strip structure 155 extending to the area where the gap 154 is located can fill the gap 154 and directly contact the piezoelectric layer 130 .

[0119] In this embodiment, the gap region is the region where the gap 154 is located, and the first metal strip structure 155 extends to the region where the gap 154 is located. An insulating layer 1010 may be provided between the first metal strip structure 155 extending to the region where the gap 154 is located and the piezoelectric layer 130 .

[0120] The insulating layer 1010 may be made of insulating material.

[0121] like Figure 9 As shown, the first metal strip structure 155 extending to the area where the gap 154 is located fills the gap 154 and directly contacts the piezoelectric layer 130; Figure 10 As shown, an insulating layer 1010 is provided between the first metal strip structure 155 extending to the area where the gap 154 is located and the piezoelectric layer 130 .

[0122] The following describes the optimization results of the surface acoustic wave resonator according to the embodiment of the present application.

[0123] First, the length l1 of the first portion 152 along the first direction and the duty ratio DF1 of the first portion 152 are optimized.

[0124] In which, the interdigital transducer may include multiple periodic structures, a periodic structure includes a first interdigit and a gap between the first interdigits, and the duty cycle of the first part 152 can be the ratio of the length of the first part 152 along the second direction within the periodic structure to the length of the periodic structure where the first part 152 is located along the second direction.

[0125] In this embodiment, the duty cycle of the second portion 153 is 0.5. When DF1 is fixed to 0.8, the optimization result of the surface acoustic wave resonator is as follows: Figure 11 shown.

[0126] Figure 11 This is an optimization result corresponding to the surface acoustic wave resonator in which the width of the first portion 152 along the second direction is greater than the width of the second portion 153 along the second direction, and the width of the gap 154 along the first direction is less than the first distance.

[0127] Figure 11 Schematic diagram of the effect of the admittance of the surface acoustic wave resonator changing with frequency. Figure 11 Each curve in corresponds to a different l1.

[0128] from Figure 11 It can be concluded that when l1 is 0.25 surface acoustic wave wavelengths, the stray generated by the surface acoustic wave leaking into the area corresponding to the bus bar 151 can be reduced.

[0129] When l1 is approximately three times the surface acoustic wave wavelength, spurious signals can be suppressed, but scattering losses will increase, making it unsuitable for resonators with a high quality factor.

[0130] In this embodiment, l1 is fixed to 0.25 SAW wavelengths. Adjusting the value of DF1 can adjust the speed of the SAW in the area corresponding to the first finger close to the bus bar 151, thereby improving the contact resistance of the first finger. The optimization results of the SAW resonator are shown in FIG. Figure 12 shown.

[0131] Figure 12 This is an optimization result corresponding to the surface acoustic wave resonator in which the width of the first portion 152 along the second direction is greater than the width of the second portion 153 along the second direction, and the width of the gap 154 along the first direction is less than the first distance.

[0132] Figure 12 Schematic diagram of the effect of the admittance of the surface acoustic wave resonator changing with frequency. Figure 12 Each curve in corresponds to a different DF1.

[0133] from Figure 12 It can be concluded that when DF1 is around 0.6-0.7, the lateral spurious signal is reduced.

[0134] Next, the first metal strip structure 155 of the surface acoustic wave resonator of the embodiment of the present application is optimized. The material of the first metal strip structure 155 can be copper (Cu).

[0135] Figure 13 and Figure 14The optimization result corresponds to a surface acoustic wave resonator in which the width of the first portion 152 along the second direction is greater than the width of the second portion 153 along the second direction, the width of the gap 154 along the first direction is less than the first distance, and the first metal strip structure 155 is arranged near the first fork finger on the bus bar 151.

[0136] Figure 13 and Figure 14 Schematic diagram of the effect of the admittance of the surface acoustic wave resonator changing with frequency.

[0137] like Figure 13 As shown, the thickness optimization results of the first metal strip structure 155 are listed, and the width of the first metal strip structure 155 along the first direction is fixed to 0.25 surface acoustic wave wavelengths. Figure 13 Each curve corresponds to a different thickness of the first metal strip structure 155 .

[0138] from Figure 13 It can be seen from the graph that the thickness of the first metal strip structure 155 is different, and the spurious mode amplitude in the corresponding area of the bus bar 151 is different. When the thickness of the first metal strip structure 155 is 20 nm, the spurious mode amplitude is reduced near 2050 MHz.

[0139] like Figure 14 As shown, the optimization results of the width of the first metal strip structure 155, that is, the width along the first direction, are listed, and the thickness of the first metal strip structure 155 is fixed to 20nm, as shown in FIG. Figure 14 Each curve corresponds to a different width of the first metal strip structure 155 .

[0140] from Figure 14 As can be seen from the figure, the width of the first metal strip structure 155 is different, and the spurious emission in the corresponding area of the busbar 151 is different. It can be seen that when the width of the first metal strip structure 155 is around 0.2 surface acoustic wave wavelengths to 0.3 surface acoustic wave wavelengths, the optimization result is the best.

[0141] The following compares the performance of the surface acoustic wave resonator of the embodiment of the present application with that of the surface acoustic wave resonator in the related art.

[0142] like Figure 15 and Figure 16 As shown, the impedance characteristics of the surface acoustic wave resonator of the embodiment of the present application and the surface acoustic wave resonator in the related art are compared. Figure 15 and Figure 16 Schematic diagram of the effect of the conductivity of the surface acoustic wave resonator changing with frequency.

[0143] Figure 15The performance of the surface acoustic wave resonator in which the width of the first portion 152 along the second direction is greater than the width of the second portion 153 along the second direction and the width of the gap 154 along the first direction is less than the first distance is compared with the surface acoustic wave resonator in the related art.

[0144] Figure 15 In FIG, the dotted line corresponding to Normal IDT is the surface acoustic wave resonator in the related art, and the solid line is the surface acoustic wave resonator of the embodiment of the present application.

[0145] Figure 15 The first distance corresponding to the surface acoustic wave resonator is 0.25 surface acoustic wave wavelengths, and the duty cycle of the second portion 153 is 0.6. Figure 15 It can be concluded that the surface acoustic wave resonator of the embodiment of the present application reduces the leakage and spurious emission of the surface acoustic wave.

[0146] Figure 16 The results of comparing the performance of a surface acoustic wave resonator in the related art include a first portion 152 having a width along the second direction greater than a width of the second portion 153 along the second direction, a gap 154 having a width along the first direction less than the first distance, and a first metal strip structure 155 provided on the bus bar 151 near the first interdigitated finger.

[0147] Figure 16 In FIG, the dotted line corresponding to Normal IDT is the surface acoustic wave resonator in the related art, and the solid line is the surface acoustic wave resonator of the embodiment of the present application.

[0148] Figure 16 The first distance corresponding to the surface acoustic wave resonator is 0.25 surface acoustic wave wavelengths, and the duty cycle of the second portion 153 is 0.6. Figure 16 It can be concluded that the surface acoustic wave resonator of the embodiment of the present application reduces the leakage and stray of the surface acoustic wave.

[0149] The structure of the surface acoustic wave resonator in the embodiment of the present application can also be applied to bulk acoustic wave (BAW) resonators. The surface acoustic wave resonator in the embodiment of the present application can be a temperature compensated surface acoustic wave (TC-SAW) resonator, a piezoelectric on insulator (POI) resonator, a resonator based on lithium niobate film, and a film bulk acoustic wave resonator (FBAR), etc. Among them, the resonator based on lithium niobate film can be either transversely excited or longitudinally excited.

[0150] It should be noted that the thickness of the structure of the embodiment of the present application can be the thickness of the structure along the third direction intersecting the first direction and the second direction. The third direction can be Figure 2 、 Figure 7 、 Figure 9 and Figure 10 The Z direction in .

[0151] An embodiment of the present application further provides an electronic device, which includes the above-mentioned surface acoustic wave resonator.

[0152] According to the electronic device provided by the embodiment of the present application, the width of the first portion 152 at the connection between the first finger and the bus bar 151 along the propagation direction of the surface acoustic wave is greater than the width of the second portion 153 of the first finger along the propagation direction of the surface acoustic wave, and the width of the gap 154 between the second portion 153 on one interdigital electrode and the bus bar 151 on the other interdigital electrode along the direction intersecting with the propagation direction of the surface acoustic wave is less than the first distance, and a first metal strip structure 155 is provided at a position near the first interdigital finger on the bus bar 151, which can adjust the acoustic impedance near the connection between the bus bar 151 and the first interdigital finger, thereby ensuring uniform propagation of the surface acoustic wave, reducing lateral stray waves, and improving the performance of the surface acoustic wave resonator.

[0153] The electronic device in the embodiments of the present application may be a terminal or other device other than a terminal. For example, the electronic device may be a mobile phone, a tablet computer, a laptop computer, a PDA, an in-vehicle electronic device, a mobile internet device (MID), an augmented reality (AR) / virtual reality (VR) device, a robot, a wearable device, an ultra-mobile personal computer (UMPC), a netbook, or a personal digital assistant (PDA), etc. It may also be a server, a network attached storage (NAS), a personal computer (PC), a television (TV), an ATM, or an kiosks, etc., and the embodiments of the present application do not specifically limit it.

[0154] While the above description does not provide detailed technical details regarding patterning and etching of each layer, those skilled in the art will appreciate that various technical means can be employed to form layers, regions, and the like in desired shapes. Furthermore, those skilled in the art may devise methods that differ from those described above to form the same structure. Furthermore, while each embodiment has been described separately, this does not mean that the measures in each embodiment cannot be advantageously combined.

[0155] The terms "first," "second," and the like in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of this application can be implemented in an order other than that illustrated or described herein, and that the objects distinguished by "first," "second," and the like are generally of the same type, and do not limit the number of objects; for example, the first object can be one or more. In addition, the term "and / or" in the specification and claims refers to at least one of the connected objects, and the character " / " generally indicates that the objects connected are in an "or" relationship.

[0156] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0157] In the description of this application, "first feature" and "second feature" may include one or more of the features.

[0158] In the description of this application, “plurality” means two or more.

[0159] In the description of the present application, a first feature being “on” or “under” a second feature may include the first and second features being in direct contact with each other, or the first and second features being in contact with each other not directly but via another feature therebetween.

[0160] In the description of this application, a first feature “on”, “above” and “above” a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature.

[0161] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0162] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and intent of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A surface acoustic wave resonator, characterized in that: include: Piezoelectric layer; An interdigital transducer, the interdigital transducer being disposed on one side of the piezoelectric layer, the interdigital transducer comprising two interdigital electrodes arranged opposite each other along a first direction, each of the interdigital electrodes comprising a bus bar and a first finger connected to the bus bar and extending along the first direction, the first finger comprising a first portion and a second portion, the first portion being located at a connection between the first finger and the bus bar, the width of the first portion along a second direction intersecting the first direction being greater than the width of the second portion along the second direction, a gap being defined between the second portion on one of the interdigital electrodes and the bus bar on the other interdigital electrode, the width of the gap along the first direction being less than the first distance; A first metal strip structure is provided on a side of the IDT facing away from the piezoelectric layer, and the first metal strip structure is located on the bus bar near the first interdigital finger.

2. The surface acoustic wave resonator according to claim 1, wherein The first metal strip structure is a continuous strip structure extending along the second direction.

3. The surface acoustic wave resonator according to claim 2, wherein The first metal strip structure extends along the first direction in an interdigitated region to form a first additional metal element. The interdigitated region is a region extending along the first direction corresponding to the first fingers.

4. The surface acoustic wave resonator according to claim 3, characterized in that The first additional metal element extends in at least one of a positive direction and a negative direction of the first direction.

5. The surface acoustic wave resonator according to claim 1, wherein The first metal strip structure is a block structure, and the first metal strip structure is provided in an interdigital region, and the interdigital region is a region corresponding to the first interdigit and extending along the first direction.

6. The surface acoustic wave resonator according to claim 1, wherein The first metal strip structure includes at least two first metal strips, wherein the first metal strips extend along the second direction, and the at least two first metal strips are spaced apart along the first direction.

7. The surface acoustic wave resonator according to any one of claims 1 to 6, characterized in that: Also includes: A second additional metal element is provided on a surface of the first portion facing away from the piezoelectric layer.

8. The surface acoustic wave resonator according to any one of claims 1 to 6, characterized in that: Also includes: A second metal strip structure, wherein the second metal strip structure is arranged on a side of the interdigital transducer away from the piezoelectric layer, the second metal strip structure is located on the bus bar at a position away from the first interdigital transducer, and the spacing between the second metal strip structure and the first metal strip structure along the first direction is a first target distance.

9. The surface acoustic wave resonator according to any one of claims 1 to 6, characterized in that: A projection of an edge of the first metal strip structure close to the first interdigital finger on the piezoelectric layer is located at a projection of the gap on the piezoelectric layer.

10. The surface acoustic wave resonator according to claim 9, characterized in that The first metal strip structure fills the gap, or an insulating layer is provided between the first metal strip structure and the piezoelectric layer in the gap region.

11. An electronic device, characterized in that: include: The surface acoustic wave resonator according to any one of claims 1 to 10.

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