Surface acoustic wave resonator, surface acoustic wave filter and electronic device

Abstract

The present application discloses a surface acoustic wave resonator, a surface acoustic wave filter and an electronic device, belonging to the field of semiconductor technology. The surface acoustic wave resonator includes: a substrate, including a device area, the device area includes a first edge area and a second edge area; an electrode layer located on one side of the substrate and located in the device area, including a plurality of first electrode fingers and a plurality of second electrode fingers; a dielectric layer located on the side of the electrode layer away from the substrate and covering the substrate; a first through-hole electrode and a second through-hole electrode penetrating the dielectric layer, the first through-hole electrode is located in the first edge area and connected to the first electrode finger, the second through-hole electrode is located in the second edge area and connected to the second electrode finger; a first busbar and a second busbar located on the side of the dielectric layer away from the electrode layer, the first busbar is located in the first edge area and connected to the first through-hole electrode, the second busbar is located in the second edge area and connected to the second through-hole electrode. The present application can reduce the size of the resonator and suppress the stray generated by the high-order transverse mode.

Description

Technical Field

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

[0002] Surface acoustic wave (SAW) resonators are widely used in mobile communication devices, with advantages such as low insertion loss, wide bandwidth, small size, low cost, and mass production. However, when the main mode is excited, the surface acoustic wave resonator will also generate unnecessary high-order transverse modes, and the spurious generated by the high-order transverse modes will affect the performance of the resonator. In addition, the resonator in the related art sets the busbar at both ends of the electrode finger, resulting in a larger size of the resonator. Summary of the invention

[0003] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a surface acoustic wave resonator, a surface acoustic wave filter and an electronic device, which can reduce the size of the resonator and suppress the spurious generated by the high-order transverse mode.

[0004] In a first aspect, the present application provides a surface acoustic wave resonator, comprising:

[0005] A substrate, comprising a device region, wherein the device region comprises a first edge region and a second edge region arranged opposite to each other along a first direction;

[0006] an electrode layer located at one side of the substrate along the second direction and located in the device region, the electrode layer comprising a plurality of electrode fingers extending along the first direction and spaced apart along a third direction, the first direction, the second direction and the third direction being perpendicular to each other, the plurality of electrode fingers comprising a plurality of first electrode fingers and a plurality of second electrode fingers;

[0007] a dielectric layer located on a side of the electrode layer away from the substrate and covering the substrate;

[0008] a first through-hole electrode and a second through-hole electrode respectively penetrating the dielectric layer along the second direction, the first through-hole electrode being located in the first edge region and connected to the first electrode finger, and the second through-hole electrode being located in the second edge region and connected to the second electrode finger;

[0009] A first busbar and a second busbar are located on the side of the dielectric layer away from the substrate, the first busbar is located in the first edge region and connected to the first through-hole electrode, and the second busbar is located in the second edge region and connected to the second through-hole electrode.

[0010] According to the surface acoustic wave resonator of the present application, a first through-hole electrode and a second through-hole electrode are arranged to penetrate the dielectric layer, and a first busbar and a second busbar are arranged on the side of the dielectric layer away from the electrode layer, so that the first busbar is connected to the first electrode finger in the electrode layer through the first through-hole electrode, and the second busbar is connected to the second electrode finger in the electrode layer through the second through-hole electrode, that is, the busbar is arranged above the electrode layer, and there is no need to arrange the busbars at both ends of the electrode layer, thereby effectively reducing the size of the resonator, and the first through-hole electrode, the second through-hole electrode, the first busbar and the second busbar are located in the edge area of ​​the electrode layer to generate a mass load effect in the edge area, suppress lateral energy leakage, and thus suppress the spurious generated by high-order transverse modes.

[0011] According to one embodiment of the present application, the surface acoustic wave resonator includes a plurality of the first through-hole electrodes and a plurality of the second through-hole electrodes;

[0012] The plurality of first through-hole electrodes are sequentially distributed along the third direction and are connected to the plurality of first electrode fingers in a one-to-one correspondence; the first busbar extends along the third direction and is respectively connected to the plurality of first through-hole electrodes;

[0013] The plurality of second through-hole electrodes are sequentially distributed along the third direction and connected to the plurality of second electrode fingers in one-to-one correspondence. The second bus bar extends along the third direction and is respectively connected to the plurality of second through-hole electrodes.

[0014] According to an embodiment of the present application, every at least one adjacent first electrode finger forms a first electrode finger group, every at least one adjacent second electrode finger forms a second electrode finger group, and the first electrode finger groups and the second electrode finger groups are alternately distributed along the third direction.

[0015] According to an embodiment of the present application, the dielectric layer at least covers the device region.

[0016] According to an embodiment of the present application, the substrate further includes a peripheral region located around the device region, the peripheral region is at least located outside the first edge region and / or the second edge region, and the dielectric layer also covers a portion of the peripheral region.

[0017] According to one embodiment of the present application, the device region further includes a body region located between the first edge region and the second edge region;

[0018] The thickness of the dielectric layer in the first edge region and the second edge region is greater than the thickness of the dielectric layer in the main region.

[0019] According to one embodiment of the present application, the surface acoustic wave resonator further includes a first electrode line located inside the dielectric layer, the first electrode line being located in the first edge region and extending along the third direction;

[0020] and / or,

[0021] The surface acoustic wave resonator further includes a second electrode line located inside the dielectric layer, wherein the second electrode line is located in the second edge region and extends along the third direction.

[0022] According to one embodiment of the present application, when the surface acoustic wave resonator includes a first electrode line, the first electrode line is connected to the first through-hole electrode;

[0023] In a case where the surface acoustic wave resonator includes the second electrode line, the second electrode line is connected to the second through-hole electrode.

[0024] According to an embodiment of the present application, the first electrode finger includes a first end portion located in the first edge region, the width of the first end portion is greater than the width of the main body of the first electrode finger, and the first through-hole electrode is connected to the first end portion;

[0025] and / or,

[0026] The second electrode finger includes a second end portion located in the second edge region, a width of the second end portion is greater than a body width of the second electrode finger, and the second through-hole electrode is connected to the second end portion.

[0027] According to an embodiment of the present application, the surface acoustic wave resonator further includes a third electrode line located on a side of the dielectric layer away from the substrate, the third electrode line is located in the first edge region, and the third electrode line overlaps with the first electrode finger and the second electrode finger in the second direction;

[0028] and / or,

[0029] The surface acoustic wave resonator further includes a fourth electrode line located on a side of the dielectric layer away from the substrate. The fourth electrode line is located in the second edge region and overlaps the first electrode finger and the second electrode finger in the second direction.

[0030] In a second aspect, the present application provides a surface acoustic wave filter, comprising the surface acoustic wave resonator as described in the first aspect above.

[0031] In a third aspect, the present application provides an electronic device comprising the surface acoustic wave filter as described in the second aspect above.

[0032] The above one or more technical solutions in the embodiments of the present application have at least one of the following technical effects:

[0033] By arranging a first through-hole electrode and a second through-hole electrode penetrating the dielectric layer, and arranging a first busbar and a second busbar on the side of the dielectric layer away from the electrode layer, the first busbar is connected to the first electrode finger in the electrode layer through the first through-hole electrode, and the second busbar is connected to the second electrode finger in the electrode layer through the second through-hole electrode, that is, the busbar is arranged above the electrode layer, and there is no need to arrange the busbars at both ends of the electrode layer, thereby effectively reducing the size of the resonator, and the first through-hole electrode, the second through-hole electrode, the first busbar and the second busbar are located in the edge area of ​​the electrode layer to generate a mass load effect in the edge area, suppress lateral energy leakage, and thus suppress the stray generated by high-order transverse modes.

[0034] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] 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:

[0036] Figure 1 is a top view of a surface acoustic wave resonator in the related art;

[0037] Figure 2 It is a schematic diagram of SAW velocity in a surface acoustic wave resonator in the related art;

[0038] Figure 3 is one of the top views of the surface acoustic wave resonator provided in the embodiment of the present application;

[0039] Figure 4 It is one of the structural schematic diagrams of the surface acoustic wave resonator provided in the embodiment of the present application;

[0040] Figure 5 is a schematic diagram of the SAW velocity in the surface acoustic wave resonator provided in an embodiment of the present application;

[0041] Figure 6 is a curve relationship diagram of frequency and admittance of a surface acoustic wave resonator provided in an embodiment of the present application;

[0042] Figure 7 is a curve relationship diagram of frequency and conductance of a surface acoustic wave resonator provided in an embodiment of the present application;

[0043] Figure 8 This is a second top view of the surface acoustic wave resonator provided in an embodiment of the present application;

[0044] Fig. 9 This is a third top view of the surface acoustic wave resonator provided in an embodiment of the present application;

[0045] Fig.10This is the second structural schematic diagram of the surface acoustic wave resonator provided in the embodiment of the present application;

[0046] Fig.11 is one of the curve relationship diagrams of the frequency, admittance and conductance of the surface acoustic wave resonator provided in the embodiment of the present application;

[0047] Fig.12 is a curve relationship diagram of the frequency and Q value of the surface acoustic wave resonator provided in the embodiment of the present application;

[0048] Fig.13 This is a fourth top view of the surface acoustic wave resonator provided in an embodiment of the present application;

[0049] Fig.14 This is the third structural schematic diagram of the surface acoustic wave resonator provided in the embodiment of the present application;

[0050] Fig.15 This is a fifth top view of the surface acoustic wave resonator provided in an embodiment of the present application;

[0051] Fig.16 This is the fourth structural schematic diagram of the surface acoustic wave resonator provided in the embodiment of the present application;

[0052] Fig.17 This is the second graph of the relationship between the frequency, admittance and conductance of the surface acoustic wave resonator provided in the embodiment of the present application;

[0053] Fig.18 This is the sixth top view of the surface acoustic wave resonator provided in the embodiment of the present application;

[0054] Fig.19 This is the fifth structural schematic diagram of the surface acoustic wave resonator provided in the embodiment of the present application. DETAILED DESCRIPTION

[0055] The embodiments of the present application are described in detail below, and 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 cannot be understood as limiting the present application.

[0056] In related technologies, such as Figure 1 As shown, the surface acoustic wave resonator SAW includes a main body region 101, two gap regions 102a and 102b located at opposite sides of the main body region 101 along a first direction A, and two busbar regions 103a and 103b located at the side of the two gap regions 102a and 102b away from the main body region 101.

[0057] The surface acoustic wave resonator includes an interdigital transducer (IDT), two busbars 110a and 110b, and a dielectric layer 130 covering the interdigital transducer and the two busbars. The first electrode finger 120a in the interdigital transducer is located in the main body region 101 and the gap region 102a and is connected to the busbar 110a in the busbar region 103a, and the second electrode finger 120b in the interdigital transducer is located in the main body region 101 and the gap region 102b and is connected to the busbar 110b in the busbar region 103b.

[0058] Combination Figure 2 As shown, the SAW velocity of the two busbar regions 103a and 103b of the surface acoustic wave resonator is V Busbar , the SAW rate of the two gap regions 102a and 102b is V Gap , the SAW rate of the main region 101 is V IDT , V Gap >V IDT >V Busbar , resulting in lateral energy leakage of the resonator and generating high-order transverse modes, which in turn generate spurious signals and affect the performance of the resonator. In addition, the two busbars 110a and 110b are located on opposite sides of the IDT along the first direction A, resulting in a larger size of the resonator.

[0059] Based on this, the present application provides a surface acoustic wave resonator, a surface acoustic wave filter and an electronic device.

[0060] Figure 3 and Figure 4 A schematic diagram of the structure of a surface acoustic wave resonator provided in an embodiment of the present application.

[0061] like Figure 3 and Figure 4 As shown, the surface acoustic wave resonator includes a substrate 1 , an electrode layer 2 , a dielectric layer 3 , a first through-hole electrode 41 , a second through-hole electrode 42 , a first busbar 51 and a second busbar 52 .

[0062] The substrate 1 includes a device area 10, and the device area 10 is used to set a surface acoustic wave device. The device area 10 includes a first edge area 11 and a second edge area 12 that are relatively arranged along a first direction A. The device area 10 may also include a main area 13 located between the first edge area 11 and the second edge area 12. In some embodiments, the substrate 1 may also include a peripheral area 14, and the peripheral area 14 is located on the peripheral side of the device area 10, and the peripheral area 14 is at least located outside the first edge area 11 and / or the second edge area 12. For example, the peripheral area 14 is located on opposite sides of the device area 10 along the first direction A, that is, the peripheral area 14 is located outside the first edge area 11 and the second edge area 12. In some embodiments, the substrate 1 includes a piezoelectric substrate and other structural layers located below the piezoelectric substrate. Among them, the material of the substrate 1 may include 128°YX-LiNbO3, etc.

[0063] The electrode layer 2 is located on one side of the substrate 1 along the second direction B, and the second direction B is perpendicular to the first direction A. In the case where the substrate 1 includes a piezoelectric substrate and other structural layers located below the piezoelectric substrate, the electrode layer 2 is located above the piezoelectric substrate. The electrode layer 2 is located in the device region 10 of the substrate 1. The electrode layer 2 includes a plurality of electrode fingers, each of which extends along the first direction A, and the plurality of electrode fingers are spaced apart along the third direction C. The third direction C is perpendicular to the first direction A, and the third direction C is perpendicular to the second direction B.

[0064] The plurality of electrode fingers include a plurality of first electrode fingers 21 and a plurality of second electrode fingers 22. Each first electrode finger 21 extends along a first direction A in the device region 10 to extend from the main region 13 along the first direction A to the first edge region 11 and the second edge region 12. Each second electrode finger 22 extends along a first direction A in the device region 10 to extend from the main region 13 along the first direction A to the first edge region 11 and the second edge region 12. The plurality of first electrode fingers 21 and the plurality of second electrode fingers 22 are spaced apart along a third direction C. The number of the first electrode fingers 21 and the second electrode fingers 22 may be the same. The sizes (including length and width, etc.) of the first electrode fingers 21 and the second electrode fingers 22 may be the same. The materials of the first electrode fingers 21 and the second electrode fingers 22 may both include metal materials such as copper.

[0065] The dielectric layer 3 is located on the side of the electrode layer 2 facing away from the substrate 1, and the dielectric layer 3 covers the electrode layer 2 and the substrate 1. The material of the dielectric layer 3 includes silicon oxide, such as silicon dioxide.

[0066] The first through-hole electrode 41 penetrates the dielectric layer 3 along the second direction B, and the first through-hole electrode 41 is located in the first edge region 11 and connected to the first electrode finger 21. In some embodiments, the surface acoustic wave resonator may include a plurality of first through-hole electrodes 41, and the number of the first through-hole electrodes 41 may be the same as the number of the first electrode fingers 21. The plurality of first through-hole electrodes 41 are all located in the first edge region 11, and the plurality of first through-hole electrodes 41 are connected to the plurality of first electrode fingers 21 in a one-to-one correspondence.

[0067] The second through-hole electrode 42 penetrates the dielectric layer 3 along the second direction B, and the second through-hole electrode 42 is located in the second edge region 11 and connected to the second electrode finger 22. In some embodiments, the surface acoustic wave resonator may include a plurality of second through-hole electrodes 42, and the number of the second through-hole electrodes 42 may be the same as the number of the second electrode fingers 22. The plurality of second through-hole electrodes 42 are all located in the second edge region 12, and the plurality of second through-hole electrodes 42 are connected to the plurality of second electrode fingers 22 in a one-to-one correspondence.

[0068] The material, thickness (thickness along the second direction B) and width (width along the first direction A) of the first through-hole electrode 41 may be the same or different. The material of the first through-hole electrode 41 and the second through-hole electrode 42 may include metal materials such as copper.

[0069] The first busbar 51 is located on the side of the dielectric layer 3 away from the electrode layer 2, the first busbar 51 is located in the first edge region 11, and the first busbar 51 extends along the third direction C in the first edge region 11, and the first busbar 51 is connected to the first through-hole electrode 41, so that the first busbar 51 is connected to the first electrode finger 21 through the first through-hole electrode 41.

[0070] When the surface acoustic wave resonator includes a plurality of first through-hole electrodes 41, the first busbar 51 is respectively connected to the plurality of first through-hole electrodes 41. In some embodiments, the plurality of first through-hole electrodes 41 are sequentially distributed along the third direction C, and the first busbar 51 extends along the third direction C and is respectively connected to the plurality of first through-hole electrodes 41.

[0071] The second busbar 52 is located on the side of the dielectric layer 3 away from the electrode layer 2, the second busbar 52 is located in the second edge area 12, and the second busbar 52 extends along the third direction C in the second edge area 12. The second busbar 52 is connected to the second through-hole electrode 42, so that the second busbar 52 is connected to the second electrode finger 22 through the second through-hole electrode 42.

[0072] When the surface acoustic wave resonator includes a plurality of second through-hole electrodes 42, the second busbar 52 is respectively connected to the plurality of second through-hole electrodes 42. In some embodiments, the plurality of second through-hole electrodes 42 are sequentially distributed along the third direction C, and the first busbar 51 extends along the third direction C and is respectively connected to the plurality of second through-hole electrodes 42.

[0073] The first busbar 51 and the second busbar 52 can be used as connecting wires connecting adjacent resonators or connecting wires connecting the package side. The material, thickness (thickness along the second direction B) and width (width along the first direction A) of the first busbar 51 and the second busbar 52 can be the same or different. The materials of the first busbar 51 and the second busbar 52 can both include metal materials such as copper.

[0074] In this embodiment, the first busbar 51 and the second busbar 52 are arranged on the side of the dielectric layer 3 away from the electrode layer 2, so that the first busbar 51 is connected to the first electrode finger 21 in the electrode layer 2 through the first through-hole electrode 41 penetrating the dielectric layer 3, and the second busbar 52 is connected to the second electrode finger 22 in the electrode layer 2 through the second through-hole electrode 42 penetrating the dielectric layer 3, that is, the busbar is arranged above the electrode layer 2, and there is no need to arrange the busbars at both ends of the electrode layer 2, thereby reducing the size of the resonator.

[0075] It can be further understood that the device area 10 is equivalent to Figure 1 The main region 101 in the device region 10 is replaced by arranging a busbar above the electrode layer 2 in the device region 10. Figure 1 The busbar area 103a, 103b in the Figure 1 The gap area and busbar area in the device are reduced, thereby reducing the size of the resonator and the size of the device chip.

[0076] Furthermore, the first through-hole electrode 41 and the first busbar 51 are located in the first edge region 11, and the second through-hole electrode 42 and the second busbar 52 are located in the second edge region 12, so as to generate a mass loading effect in the first edge region 11 and the second edge region 12 and reduce the SAW rate in the first edge region 11 and the second edge region 12. Figure 5 As shown, the SAW rate of the peripheral region 14 is V s , the SAW rate of the area corresponding to the first busbar 51 and the second busbar 52 is V via , the SAW rate of other regions (including the main region 13) is V IDT , V s >V IDT >V via Compared with the main region 13, the SAW rate of the first edge region 11 and the second edge region 12 is reduced to suppress lateral energy leakage, thereby suppressing high-order transverse modes and the spurious generated by them.

[0077] It should be noted that by adjusting the material, thickness and width of the first through-hole electrode 41 , the second through-hole electrode 42 , the first busbar 51 and the second busbar 52 , the mass load effect generated in the first edge area 11 and the second edge area 12 can be adjusted, thereby affecting the suppression effect.

[0078] For example, the wavelength of the surface acoustic wave is L=4μm, the length of the electrode finger (including the first electrode finger 21 and the second electrode finger 22) along the first direction A is 20L=80μm, the thickness of the electrode finger along the second direction B is 0.075L=300nm, the thickness of the dielectric layer 3 along the second direction B is 0.25L=1μm, the distance between the through-hole electrode (including the first through-hole electrode 41 and the second through-hole electrode 42) and the nearest end face of the electrode finger connected to it is L / 16=250nm, the cross-section of the through-hole electrode along the first direction A is square, and the side length of the square is L / 8=500nm, and the thickness of the through-hole electrode along the second direction B is 700mm. When the thickness of the busbars (including the first busbar 51 and the second busbar 52) along the second direction B is set to 0.006L=25nm, 0.013L=50nm, 0.019L=75nm and 0.025L=100nm respectively, the admittance and conductance characteristics of the resonator are respectively as follows: Figure 6 and Figure 7As shown. It can be seen that, compared with the resonator in the related art, the resonator in this embodiment can effectively suppress the spurious of the admittance and conductance characteristics, and the suppression effect can be adjusted by adjusting the thickness of the busbar along the second direction B. In particular, by setting the thickness of the busbar (including the first busbar 51 and the second busbar 52) along the second direction B to 0.019*L (75nm), the spurious of the admittance and conductance characteristics can be effectively suppressed.

[0079] In some embodiments, every at least one adjacent first electrode finger 21 forms a first electrode finger group, every at least one adjacent second electrode finger 22 forms a second electrode finger group, and the first electrode finger groups and the second electrode finger groups are alternately distributed along the third direction C.

[0080] Among them, a plurality of first electrode fingers 21 may constitute at least one first electrode finger group, and the number of first electrode fingers 21 in different first electrode finger groups may be the same or different. A plurality of second electrode fingers 22 may constitute at least one second electrode finger group, and the number of second electrode fingers 22 in different second electrode finger groups may be the same or different. The number of first electrode finger groups and second electrode finger groups may be the same or different.

[0081] like Figure 3 As shown, each first electrode finger 21 can constitute a first electrode finger group, and multiple first electrode fingers 21 constitute multiple first electrode finger groups. Each second electrode finger 22 can constitute a second electrode finger group, and multiple second electrode fingers 22 constitute multiple second electrode finger groups. Multiple first electrode finger groups and multiple second electrode finger groups are alternately distributed along the third direction C, that is, multiple first electrode fingers 21 and multiple second electrode fingers 22 are alternately distributed along the third direction C. There is one second electrode finger 22 between any two adjacent first electrode fingers 21, and there is one first electrode finger 21 between any two adjacent second electrode fingers 22.

[0082] like Figure 8 As shown, a plurality of first electrode fingers 21 constitute a first electrode finger group, a plurality of second electrode fingers 22 constitute a second electrode finger group, and the first electrode finger group and the second electrode finger group are alternately distributed along the third direction C, that is, the first electrode finger group is located on one side of the second electrode finger group along the third direction C. It should be noted that the plurality of first electrode fingers 21 and the plurality of second electrode fingers 22 may also be distributed in other ways, as long as the plurality of electrode fingers are distributed along the third direction C, which is not specifically limited here.

[0083] In some embodiments, Figure 3 and Figure 8As shown, the first electrode finger 21 and the second electrode finger 22 completely overlap along the third direction C. Complete overlap means that the orthographic projection of the first electrode finger 21 on the target plane completely overlaps with the orthographic projection of the second electrode finger 22 on the target plane, and the target plane is perpendicular to the third direction C.

[0084] In some embodiments, Figure 3 and Figure 8 As shown, the dielectric layer 3 may completely cover the device region 10 and the peripheral region 14 .

[0085] In some embodiments, the dielectric layer 3 may only cover the device region 10 , that is, the dielectric layer 3 in the peripheral region 14 is removed so that the peripheral region 14 does not have the dielectric layer 3 .

[0086] In some embodiments, Fig. 9 and Fig.10 As shown, the dielectric layer 3 may cover the device region 10 and a portion of the peripheral region 14 , that is, a portion of the dielectric layer 3 in the peripheral region 14 is removed.

[0087] Since there are no busbars at both ends of the electrode layer 2 along the first direction A, the SAW energy is easily leaked to the outside of the electrode layer 2, thereby affecting the Q value of the resonator. By removing the dielectric layer 3 at both ends of the electrode layer 2, that is, removing at least part of the dielectric layer 3 in the peripheral area 14, the SAW energy can be confined to the electrode layer 2 to prevent it from leaking to the outside of the electrode layer 2, thereby reducing the size of the resonator and suppressing strays, while improving the Q value of the resonator.

[0088] For example, the wavelength of the surface acoustic wave is L=4μm, the length of the electrode finger (including the first electrode finger 21 and the second electrode finger 22) along the first direction A is 20L=80μm, the thickness of the electrode finger along the second direction B is 0.075L=300nm, the thickness of the dielectric layer 3 along the second direction B is 0.25L=1μm, the distance between the through-hole electrode (including the first through-hole electrode 41 and the second through-hole electrode 42) and the nearest end surface of the electrode finger connected thereto is L / 16=250nm, the cross-section of the through-hole electrode along the first direction A is square, and the side length of the square is L / 8=500nm, the thickness of the through-hole electrode along the second direction B is 700mm, and the thickness of the busbar (including the first busbar 51 and the second busbar 52) along the second direction B is 0.019L=75nm. Part of the dielectric layer 3 in the peripheral area 14 is removed, and the length of the remaining dielectric layer 3 in the peripheral area 14 along the first direction A is 0.25L=1μm (such as Fig. 9 The resonator has the following characteristics: Fig.11 As shown, the Q value of the resonator is Fig.12It can be seen that, compared with the resonator in the related art and the resonator in the above embodiment where the dielectric layer is not removed (the busbar thickness is 75 nm), the resonator in this embodiment removes part of the dielectric layer 3 at both ends of the electrode layer 2 along the first direction A, which can improve the Q value of the resonator, and the admittance and conductance characteristics in the frequency range near the anti-resonance point are also improved accordingly.

[0089] In some embodiments, the thickness of the dielectric layer 3 in the first edge region 11 and the second edge region 12 is greater than the thickness of the dielectric layer 3 in the main region 13. By increasing the thickness of the dielectric layer 3 in the first edge region 11 and the second edge region 12 (especially the edge regions corresponding to the first busbar 51 and the second busbar 52) and reducing the thickness of the dielectric layer 3 in the main region 13, the difference in SAW rate between the edge region and the main region 13 can be further reduced, thereby further suppressing the spurious generated by the high-order transverse mode.

[0090] In some embodiments, Fig.13 and Fig.14 As shown, the surface acoustic wave resonator may further include a first electrode line 61 and / or a second electrode line 62 .

[0091] When the surface acoustic wave resonator includes the first electrode line 61 , the first electrode line 61 is located inside the dielectric layer 3 , and the first electrode line 61 is located in the first edge region 11 and extends along the third direction C. The first electrode line 61 may be spaced apart from the first through-hole electrode 41 , or the first electrode line 61 may be connected to the first through-hole electrode 41 .

[0092] When the first electrode line 61 is connected to the first through-hole electrode 41, the first electrode line 61 is located directly below the first bus bar 51. The material, thickness (thickness along the second direction B) and width (width along the first direction A) of the first electrode line 61 and the first bus bar 51 may be the same or different. By adjusting the material, thickness and width of the first electrode line 61 and the first bus bar 51, the mass load effect of the first edge region 11 may be adjusted.

[0093] When the surface acoustic wave resonator includes the second electrode line 62 , the second electrode line 62 is located inside the dielectric layer 3 , and the second electrode line 62 is located in the second edge region 12 and extends along the third direction C. The second electrode line 62 may be spaced apart from the second through-hole electrode 42 , or the second electrode line 62 may be connected to the second through-hole electrode 42 .

[0094] In the case where the second electrode line 62 can be connected to the second through-hole electrode 42, the second electrode line 62 is located directly below the second bus bar 52. The material, thickness (thickness along the second direction B) and width (width along the first direction A) of the second electrode line 62 and the second bus bar 52 can be the same or different. By adjusting the material, thickness and width of the second electrode line 62 and the second bus bar 52, the mass load effect of the second edge area 12 can be adjusted.

[0095] In addition, the provision of the first electrode line 61 and / or the second electrode line 62 can improve the degree of freedom in designing the resonator.

[0096] In the case where the surface acoustic wave resonator includes only the first electrode line 61 or the second electrode line 62, the materials, thicknesses, widths, etc. of the first busbar 51 and the second busbar 52 may be different to ensure that the SAW rates of the first edge region 11 and the second edge region 12 are synchronously reduced. For example, in the case where the surface acoustic wave resonator includes only the first electrode line 61, the thickness of the second busbar 52 may be greater than the thickness of the first busbar 51 to synchronously reduce the SAW rates of the first edge region 11 and the second edge region 12 and suppress the spurious generated by the high-order transverse mode.

[0097] In some embodiments, when the surface acoustic wave resonator includes a first electrode line 61 and / or a second electrode line 62, the dielectric layer 3 may only cover the device area 10, or the dielectric layer 3 may cover the device area 10 and a portion of the peripheral area 14 to reduce the size of the resonator, further suppress the spurious generated by high-order transverse modes, and improve the Q value of the resonator.

[0098] In some embodiments, Fig.15 and Fig.16 As shown, the first electrode finger 21 includes a first end portion 210 located in the first edge region 11, and the width of the first end portion 210 (the width along the third direction C) is greater than the body width of the first electrode finger 21. The body width of the first electrode finger 21 may be the width of other parts of the first electrode finger 21 except the first end portion 210 along the third direction C (such as the width of the first electrode finger 21 in the body region 13 along the third direction C). The first through-hole electrode 41 is connected to the first end portion 210.

[0099] Since the first through-hole electrode 41 is formed on the first electrode finger 21, the width of the first through-hole electrode 41 is limited by the width of the first electrode finger 21, and the width of the first electrode finger 21 is small, so that the width of the first through-hole electrode 41 formed on the first electrode finger 21 is small, and the process difficulty is relatively large. In this embodiment, the width of the first end 210 of the first electrode finger 21 is increased, so that the first through-hole electrode 41 is formed on the first end 210, and the width of the first through-hole electrode 41 can be increased, which helps to increase the margin of the formation process of the first through-hole electrode 41, reduce the process difficulty, and further reduce the SAW rate of the first edge region 11, thereby further suppressing the spurious generated by the high-order transverse mode.

[0100] In some embodiments, Fig.15 and Fig.16 As shown, the second electrode finger 22 includes a second end portion 220 located in the second edge region 12, and the width of the second end portion 220 (the width along the third direction C) is greater than the body width of the second electrode finger 22. The body width of the second electrode finger 22 may be the width of other parts of the second electrode finger 22 except the second end portion 220 along the third direction C (such as the width of the second electrode finger 22 in the body region 13 along the third direction C). The second through-hole electrode 42 is connected to the second end portion 220.

[0101] Since the second through-hole electrode 42 is formed on the second electrode finger 22, the width of the second through-hole electrode 42 is limited by the width of the second electrode finger 22, and the width of the second electrode finger 22 is small, so that the width of the second through-hole electrode 42 formed on the second electrode finger 22 is small, and the process difficulty is relatively large. In this embodiment, the width of the second end 220 is increased, so that the second through-hole electrode 42 is formed on the second end 220, and the width of the second through-hole electrode 42 can be increased, which helps to increase the margin of the second through-hole electrode 42 formation process, reduce the process difficulty, and further reduce the SAW rate of the second edge region 12, thereby further suppressing the spurious generated by the high-order transverse mode.

[0102] In some embodiments, the first electrode finger 21 and the second electrode finger 22 completely overlap along the third direction C, that is, the orthographic projection of the first electrode finger 21 on the target plane completely overlaps the orthographic projection of the second electrode finger 22 on the target plane. The orthographic projection of the first end 210 on the target plane is located within the orthographic projection of the second electrode finger 22 on the target plane, and the orthographic projection of the second end 220 on the target plane is located within the orthographic projection of the first electrode finger 21 on the target plane, and the target plane is perpendicular to the third direction C. Since the first electrode finger 21 and the second electrode finger 22 are arranged at intervals, the width of the first end 210 of the first electrode finger 21 and / or the width of the second end 220 of the second electrode finger 22 can be appropriately increased.

[0103] In some embodiments, Fig.15As shown, the first electrode finger 21 and the second electrode finger 22 partially overlap along the third direction C, that is, the orthographic projection of the first electrode finger 21 on the target plane partially overlaps with the orthographic projection of the second electrode finger 22 on the target plane, and the target plane is perpendicular to the third direction C. Among them, the first end 210 of the first electrode finger 21 does not overlap with the second electrode finger 22 along the third direction C, and the second end 220 of the second electrode finger 22 does not overlap with the first electrode finger 21 along the third direction C, that is, the orthographic projection of the first end 210 on the target plane does not overlap with the orthographic projection of the second electrode finger 22 on the target plane, and the orthographic projection of the second end 220 on the target plane does not overlap with the orthographic projection of the first electrode finger 21 on the target plane. In this embodiment, the width of the first end 210 and / or the second end 220 can be further increased without being limited by the spacing between the first electrode finger 21 and the second electrode finger 22.

[0104] In order to ensure that the main body length of the first electrode finger 21 and the second electrode finger 22 remains unchanged, the overall length of the first electrode finger 21 and the second electrode finger 22 may be increased. The width of the first edge region 11 and the second edge region 12 along the third direction C may be increased, a first end portion 210 may be added to the first edge region 11, and the first end portion 210 may be used as an extension of the first electrode finger 21 to extend the overall length of the first electrode finger 21 (the main body length may remain unchanged), and a second end portion 220 may be added to the second edge region 12, and the second end portion 220 may be used as an extension of the second electrode finger 22 to extend the overall length of the second electrode finger 22 (the main body length may remain unchanged).

[0105] In order to reduce the size of the resonator, the main body length of the first electrode finger 21 and the second electrode finger 22 can be shortened while ensuring that the overall length of the first electrode finger 21 and the second electrode finger 22 remains unchanged. The end of the first electrode finger 21 in the first edge region 11 is extended to the first end 210, and the overall length of the first electrode finger 21 remains unchanged. The end of the second electrode finger 22 in the second edge region 12 is extended to the second end 220, and the overall length of the second electrode finger 22 remains unchanged.

[0106] For example, the wavelength of the surface acoustic wave is L=4μm, the length of the electrode finger (including the first electrode finger 21 and the second electrode finger 22) along the first direction A is 20L=80μm, the thickness of the electrode finger along the second direction B is 0.075L=300nm, the thickness of the dielectric layer 3 along the second direction B is 0.25L=1μm, the distance between the through-hole electrode (including the first through-hole electrode 41 and the second through-hole electrode 42) and the nearest end surface of the electrode finger connected thereto is L / 16=250nm, the cross-section of the through-hole electrode along the first direction A is square, and the side length of the square is L / 8=500nm, the thickness of the through-hole electrode along the second direction B is 700mm, and the thickness of the busbar (including the first busbar 51 and the second busbar 52) along the second direction B is 0.019L=75nm. The cross section of the end portion (including the first end portion 210 and the second end portion 220) along the first direction A is rectangular, the length of the end portion along the first direction A is 1 μm, and the width of the end portion along the third direction C is 1.2 μm. The admittance and conductance characteristics of the resonator are respectively as follows: Fig.17 It can be seen that, compared with the resonator in the related art, the width of the end of the resonator in this embodiment is increased, which helps to increase the margin of the through-hole electrode formation process and further suppress the spurious generated by the high-order transverse mode.

[0107] In some embodiments, when the first electrode finger 21 includes the first end 210, and / or the second electrode finger 22 includes the second end 220, the dielectric layer 3 may only cover the device area 10, or the dielectric layer 3 may cover the device area 10 and a portion of the peripheral area 14, so as to reduce the size of the resonator, increase the margin of the through-hole electrode formation process, and further suppress the spurious generated by the high-order transverse mode, while improving the Q value of the resonator.

[0108] In some embodiments, when the first electrode finger 21 includes the first end 210, and / or the second electrode finger 22 includes the second end 220, the surface acoustic wave resonator also includes a first electrode line 61 and / or a second electrode line 62 to reduce the size of the resonator, increase the margin of the through-hole electrode formation process, and further suppress the spurious generated by high-order transverse modes, while increasing the design freedom of the resonator.

[0109] In some embodiments, Fig.18 and Fig.19 As shown, the surface acoustic wave resonator further includes a third electrode line 63 and / or a fourth electrode line 64 .

[0110] In the case where the surface acoustic wave resonator includes the third electrode line 63, the third electrode line 63 is located on the side of the dielectric layer 3 away from the electrode layer 2, the third electrode line 63 is located in the first edge region 11, and the third electrode line 63 overlaps with the first electrode finger 21 and the second electrode finger 22 in the second direction B, that is, the orthographic projection of the third electrode line 63 on the substrate 1 partially overlaps with the orthographic projection of the first electrode finger 21 and the second electrode finger 22 on the substrate 1. The third electrode line 63 may be spaced apart from the first bus bar 51, or the third electrode line 63 may be adjacent to the first bus bar 51 (the third electrode line 63 may be connected to the first bus bar 51). In some embodiments, the third electrode line 63 extends along the third direction C.

[0111] The third electrode line 63 and the first busbar 51 may have the same material, thickness (thickness along the second direction B), and width (width along the first direction A), or may be different. The third electrode line 63 may increase the mass load effect of the first edge region 11, expand the margin of the first through-hole electrode 41 formation process, and further suppress lateral stray. By adjusting the material, thickness, and width of the third electrode line 63, the mass load effect of the first edge region 11 may be adjusted.

[0112] In the case where the surface acoustic wave resonator includes the fourth electrode line 64, the fourth electrode line 64 is located on the side of the dielectric layer 3 away from the electrode layer 2, the fourth electrode line 64 is located in the second edge region 12, and the fourth electrode line 64 overlaps with the first electrode finger 21 and the second electrode finger 22 in the second direction B, that is, the orthographic projection of the fourth electrode line 64 on the substrate 1 partially overlaps with the orthographic projection of the first electrode finger 21 and the second electrode finger 22 on the substrate 1. The fourth electrode line 64 can be spaced apart from the second bus bar 52, or the fourth electrode line 64 can be adjacent to the second bus bar 52 (the fourth electrode line 64 can be connected to the second bus bar 52). In some embodiments, the fourth electrode line 64 extends along the third direction C.

[0113] The fourth electrode line 64 and the second busbar 52 may have the same material, thickness (thickness along the second direction B), and width (width along the first direction A), or may be different. The fourth electrode line 64 may increase the mass load effect of the second edge region 12, expand the margin of the second through-hole electrode 42 formation process, and further suppress lateral stray. By adjusting the material, thickness, and width of the fourth electrode line 64, the mass load effect of the first edge region 11 may be adjusted.

[0114] In the case where the surface acoustic wave resonator includes only the third electrode line 63 or the fourth electrode line 64, the materials, thicknesses, widths, etc. of the first busbar 51 and the second busbar 52 may be different to ensure that the SAW rates of the first edge region 11 and the second edge region 12 are synchronously reduced. For example, in the case where the surface acoustic wave resonator includes only the third electrode line 63, the thickness of the second busbar 52 may be greater than the thickness of the first busbar 51 to synchronously reduce the SAW rates of the first edge region 11 and the second edge region 12 and suppress the spurious generated by the high-order transverse mode.

[0115] In some embodiments, when the surface acoustic wave resonator includes a third electrode line 63 and / or a fourth electrode line 64, the dielectric layer 3 may only cover the device area 10, or the dielectric layer 3 may cover the device area 10 and a portion of the peripheral area 14 to reduce the size of the resonator, further suppress the spurious generated by high-order lateral modes, and improve the Q value of the resonator.

[0116] In some embodiments, Fig.18 and Fig.19 As shown, in the case where the surface acoustic wave resonator includes a third electrode line 63 and / or a fourth electrode line 64, the first electrode finger 21 may include a first end 210, and / or the second electrode finger 22 may include a second end 220, so as to reduce the size of the resonator, further suppress the stray generated by high-order transverse modes, and at the same time increase the margin of the through-hole electrode formation process.

[0117] According to the surface acoustic wave resonator provided by the embodiment of the present application, a first through-hole electrode and a second through-hole electrode are arranged to penetrate the dielectric layer, and a first busbar and a second busbar are arranged on the side of the dielectric layer away from the electrode layer, so that the first busbar is connected to the first electrode finger in the electrode layer through the first through-hole electrode, and the second busbar is connected to the second electrode finger in the electrode layer through the second through-hole electrode, that is, the busbar is arranged above the electrode layer, and there is no need to arrange the busbars at both ends of the electrode layer, thereby effectively reducing the size of the resonator; moreover, the first through-hole electrode, the second through-hole electrode, the first busbar and the second busbar are located in the edge area of ​​the electrode layer to generate a mass load effect in the edge area, suppress lateral energy leakage, and thus suppress the stray generated by high-order transverse modes.

[0118] Correspondingly, an embodiment of the present application further provides a surface acoustic wave filter, including the surface acoustic wave resonator in the above embodiment, which will not be described in detail here.

[0119] According to the surface acoustic wave filter provided by the embodiment of the present application, a first through-hole electrode and a second through-hole electrode are arranged to penetrate the dielectric layer, and a first busbar and a second busbar are arranged on the side of the dielectric layer away from the electrode layer, so that the first busbar is connected to the first electrode finger in the electrode layer through the first through-hole electrode, and the second busbar is connected to the second electrode finger in the electrode layer through the second through-hole electrode, that is, the busbar is arranged above the electrode layer, and there is no need to arrange the busbars at both ends of the electrode layer, thereby effectively reducing the size of the resonator and further reducing the size of the filter; moreover, the first through-hole electrode, the second through-hole electrode, the first busbar and the second busbar are located in the edge area of ​​the electrode layer to generate a mass load effect in the edge area, suppress lateral energy leakage, and thus suppress the stray generated by high-order transverse modes.

[0120] Correspondingly, an embodiment of the present application further provides an electronic device, including the surface acoustic wave filter in the above embodiment, which will not be described in detail here.

[0121] According to the electronic device provided in the embodiment of the present application, by setting the first through-hole electrode and the second through-hole electrode penetrating the dielectric layer, and setting the first busbar and the second busbar on the side of the dielectric layer away from the electrode layer, the first busbar is connected to the first electrode finger in the electrode layer through the first through-hole electrode, and the second busbar is connected to the second electrode finger in the electrode layer through the second through-hole electrode, that is, the busbar is set above the electrode layer, and there is no need to set the busbars at both ends of the electrode layer, which effectively reduces the size of the resonator and further reduces the size of the filter; moreover, the first through-hole electrode, the second through-hole electrode, the first busbar and the second busbar are located in the edge area of ​​the electrode layer to generate a mass load effect in the edge area, suppress lateral energy leakage, and thus suppress the stray generated by high-order transverse modes.

[0122] The terms "first", "second", etc. in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of the same type, and the number of objects is not limited. For example, the first object can be one or more.

[0123] In the description of the present application, “plurality” means two or more.

[0124] In the description of this specification, the description with reference to the terms "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 schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0125] 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 spirit 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: A substrate, comprising a device region, wherein the device region comprises a first edge region and a second edge region arranged opposite to each other along a first direction; an electrode layer located at one side of the substrate along the second direction and located in the device region, the electrode layer comprising a plurality of electrode fingers extending along the first direction and spaced apart along a third direction, the first direction, the second direction and the third direction being perpendicular to each other, the plurality of electrode fingers comprising a plurality of first electrode fingers and a plurality of second electrode fingers; a dielectric layer located on a side of the electrode layer away from the substrate and covering the substrate; A first through-hole electrode and a second through-hole electrode respectively penetrating the dielectric layer along the second direction, the first through-hole electrode being located in the first edge region and connected to the first electrode finger, and the second through-hole electrode being located in the second edge region and connected to the second electrode finger; A first busbar and a second busbar are located on the side of the dielectric layer away from the electrode layer, wherein the first busbar is located in the first edge region and connected to the first through-hole electrode, and the second busbar is located in the second edge region and connected to the second through-hole electrode.

2. The surface acoustic wave resonator according to claim 1, characterized in that: The surface acoustic wave resonator includes a plurality of the first through-hole electrodes and a plurality of the second through-hole electrodes; The plurality of first through-hole electrodes are sequentially distributed along the third direction and are connected to the plurality of first electrode fingers in a one-to-one correspondence; the first busbar extends along the third direction and is respectively connected to the plurality of first through-hole electrodes; The plurality of second through-hole electrodes are sequentially distributed along the third direction and connected to the plurality of second electrode fingers in one-to-one correspondence. The second bus bar extends along the third direction and is respectively connected to the plurality of second through-hole electrodes.

3. The surface acoustic wave resonator according to claim 1, characterized in that: Every adjacent at least one of the first electrode fingers forms a first electrode finger group, every adjacent at least one of the second electrode fingers forms a second electrode finger group, and the first electrode finger groups and the second electrode finger groups are alternately distributed along the third direction.

4. The surface acoustic wave resonator according to claim 1, characterized in that: The dielectric layer at least covers the device region.

5. The surface acoustic wave resonator according to claim 4, characterized in that: The substrate further includes a peripheral region located at a peripheral side of the device region, the peripheral region is at least located outside the first edge region and / or the second edge region, and the dielectric layer also covers a portion of the peripheral region.

6. The surface acoustic wave resonator according to claim 4, characterized in that: The device region further includes a body region located between the first edge region and the second edge region; The thickness of the dielectric layer in the first edge region and the second edge region is greater than the thickness of the dielectric layer in the main region.

7. The surface acoustic wave resonator according to any one of claims 1 to 6, characterized in that: The surface acoustic wave resonator further includes a first electrode line located inside the dielectric layer, the first electrode line being located in the first edge region and extending along the third direction; and / or, The surface acoustic wave resonator further includes a second electrode line located inside the dielectric layer, wherein the second electrode line is located in the second edge region and extends along the third direction.

8. The surface acoustic wave resonator according to claim 7, characterized in that: In the case where the surface acoustic wave resonator includes a first electrode line, the first electrode line is connected to the first through-hole electrode; In a case where the surface acoustic wave resonator includes the second electrode line, the second electrode line is connected to the second through-hole electrode.

9. The surface acoustic wave resonator according to any one of claims 1 to 6, characterized in that: The first electrode finger comprises a first end portion located in the first edge region, the width of the first end portion is greater than the width of the main body of the first electrode finger, and the first through-hole electrode is connected to the first end portion; and / or, The second electrode finger includes a second end portion located in the second edge region, a width of the second end portion is greater than a body width of the second electrode finger, and the second through-hole electrode is connected to the second end portion.

10. The surface acoustic wave resonator according to claim 9, characterized in that: The surface acoustic wave resonator further comprises a third electrode line located on a side of the dielectric layer away from the substrate, the third electrode line is located in the first edge region, and the third electrode line overlaps with the first electrode finger and the second electrode finger in the second direction; and / or, The surface acoustic wave resonator further includes a fourth electrode line located on a side of the dielectric layer away from the substrate. The fourth electrode line is located in the second edge region and overlaps the first electrode finger and the second electrode finger in the second direction.

11. The surface acoustic wave resonator according to any one of claims 1 to 6, characterized in that: The surface acoustic wave resonator further comprises a third electrode line located on a side of the dielectric layer away from the substrate, the third electrode line is located in the first edge region, and the third electrode line overlaps with the first electrode finger and the second electrode finger in the second direction; and / or, The surface acoustic wave resonator further includes a fourth electrode line located on a side of the dielectric layer away from the substrate. The fourth electrode line is located in the second edge region and overlaps the first electrode finger and the second electrode finger in the second direction.

12. A surface acoustic wave filter, characterized in that: The invention comprises a surface acoustic wave resonator as claimed in any one of claims 1 to 11.

13. An electronic device, characterized in that: The invention comprises a surface acoustic wave filter as claimed in claim 12.

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