Electronic device, electronic component, and surface acoustic wave resonator, substrate thereof and manufacturing method therefor

Abstract

Provided in the present application are an electronic device, an electronic component, and a surface acoustic wave resonator, a substrate thereof and a manufacturing method therefor. The surface acoustic wave resonator comprises a substrate, a piezoelectric layer, an interdigital transducer, and a speed regulating medium. The interdigital transducer comprises two interdigital electrodes arranged opposite to each other in a first direction, each interdigital electrode comprising a busbar and a plurality of electrode fingers. The area where the electrode fingers of the two interdigital electrodes overlap in the first direction is an electrode finger area. The electrode finger area comprises an electrode finger main area and electrode finger edge areas located on two sides of the electrode finger main area in the first direction. The area where the electrode fingers of one of the interdigital electrodes is spaced apart from the busbar of the other one of the interdigital electrodes is a gap area. The speed regulating medium is located on the side of the piezoelectric layer facing the substrate, and comprises a first speed regulating medium arranged corresponding to the electrode finger main area and / or a second speed regulating medium located in the gap area, such that the surface acoustic wave propagation speed of the electrode finger main area is greater than the surface acoustic wave propagation speed of the electrode finger edge areas.

Description

Electronic device, electronic component, surface acoustic wave resonator, substrate thereof and preparation method TECHNICAL FIELD

[0001] The present application relates to the technical field of surface acoustic wave resonators, and in particular to an electronic device, an electronic component, a surface acoustic wave resonator, a substrate thereof and a preparation method. BACKGROUND

[0002] A surface acoustic wave resonator includes a substrate, a piezoelectric layer and an interdigital transducer (IDT) formed by electrode fingers. Due to the piezoelectric effect of the piezoelectric layer, surface acoustic waves are generated and propagated within the electrode grating. The resonant characteristics of the surface acoustic wave resonator are widely used in various acoustic devices, such as radio frequency filters, duplexers, delay lines, frequency discriminators and modulators; for example, radio frequency filters based on surface acoustic wave resonators are commonly used in wireless communication devices. With the increase of frequency bands and the requirement for radio frequency spectrum utilization, people begin to expect to use surface acoustic wave devices with better performance.

[0003] However, due to the inherent waveguide characteristics of the wiring of the surface acoustic wave resonator and other reasons, in addition to the ideal primary mode surface acoustic wave, other undesirable non-primary mode acoustic waves will also be generated. These non-primary mode acoustic waves usually include transverse stray modes, which can reduce the frequency selectivity of the surface acoustic wave resonator, increase the insertion loss, reduce the signal purity, and are not conducive to signal processing and filtering effects in communication systems and other applications. Therefore, how to suppress the transverse stray mode of the surface acoustic wave resonator should be a problem to be solved at present. SUMMARY

[0004] Therefore, the embodiments of the present application provide an electronic device, an electronic component, a surface acoustic wave resonator and a preparation method thereof which are beneficial to suppressing the transverse stray mode.

[0005] The embodiments of the present application provide a surface acoustic wave resonator, which includes:

[0006] a substrate;

[0007] a piezoelectric layer disposed on the substrate, the piezoelectric layer having a piezoelectric layer upper surface facing away from the substrate;

[0008] an interdigital transducer located on the piezoelectric layer upper surface; the interdigital transducer includes two interdigital electrodes oppositely arranged along a first direction, each interdigital electrode including a bus bar and a plurality of electrode fingers extending along the first direction; an area where the electrode fingers of the two interdigital electrodes overlap along the first direction is an electrode finger area; the electrode finger area includes an electrode finger main area and electrode finger edge areas located on both sides of the electrode finger main area along the first direction; an area where the electrode fingers of one interdigital electrode are spaced apart from the bus bar of the other interdigital electrode is a gap area; and

[0009] A speed-adjusting medium is located on a side of the piezoelectric layer facing the substrate; the speed-adjusting medium comprises a first speed-adjusting medium arranged corresponding to the electrode finger main area, and / or a second speed-adjusting medium located in the gap area, for making the propagation speed of the surface acoustic wave in the electrode finger main area greater than the propagation speed of the surface acoustic wave in the electrode finger edge area.

[0010] In some embodiments, the substrate has a substrate upper surface facing the piezoelectric layer, and the substrate upper surface is provided with a first groove arranged corresponding to the electrode finger main area; the first speed-adjusting medium is arranged in the first groove; the acoustic impedance of the first speed-adjusting medium is greater than the acoustic impedance of the piezoelectric layer.

[0011] In some embodiments, the material of the first speed-adjusting medium is AlN, doped AlN, Si3N4, doped Si3N4, Al2O3, doped Al2O3, Qz, doped Qz, DLC, doped DLC, SiC or doped SiC.

[0012] In some embodiments, the thickness of the first speed-adjusting medium is in the range of 10nm-40nm.

[0013] In some embodiments, the width of the electrode finger edge area along the first direction is in the range of 0.2λ-2.0λ, where λ is the wavelength of the surface acoustic wave resonator.

[0014] In some embodiments, the substrate comprises a POI substrate; the first groove is arranged on the POI substrate;

[0015] Alternatively, the substrate comprises a POI substrate and a Bragg reflector; the Bragg reflector is located between the POI substrate and the piezoelectric layer; the first groove is arranged on the Bragg reflector.

[0016] In some embodiments, the density of the second speed-adjusting medium is greater than the density of the piezoelectric layer.

[0017] In some embodiments, the material of the second speed-adjusting medium is copper or aluminum.

[0018] In some embodiments, the thickness of the second speed-adjusting medium is in the range of 10nm-160nm;

[0019] In some embodiments, the width of the second speed-adjusting medium along the first direction is in the range of 0.4λ-1λ, where λ is the wavelength of the surface acoustic wave resonator.

[0020] In some embodiments, each gap area has a plurality of second speed-adjusting media; the plurality of second speed-adjusting media are arranged at intervals along the first direction;

[0021] In some embodiments, the substrate has a substrate upper surface facing the piezoelectric layer, the substrate upper surface is provided with a second groove, and the second velocity tuning medium is at least partially arranged in the second groove; or, the piezoelectric layer has a piezoelectric layer lower surface facing the substrate, the piezoelectric layer lower surface is provided with a third groove, and the second velocity tuning medium is at least partially arranged in the third groove.

[0022] In some embodiments, the substrate comprises a POI substrate; the second groove is arranged on the POI substrate.

[0023] Or, the substrate comprises a POI substrate and a Bragg reflector; the Bragg reflector is located between the POI substrate and the piezoelectric layer; the second groove is arranged on the Bragg reflector.

[0024] Embodiments of the present application also provide a surface acoustic wave resonator substrate, which comprises an electrode finger region and a gap region; the electrode finger region comprises an electrode finger main region and electrode finger edge regions located on both sides of the electrode finger main region along a first direction; on both sides of the electrode finger region along the first direction, the gap region is arranged.

[0025] The surface acoustic wave resonator substrate comprises:

[0026] The substrate has a substrate upper surface; and

[0027] The velocity tuning medium is arranged on the substrate upper surface, and comprises a first velocity tuning medium arranged corresponding to the electrode finger main region, and / or a second velocity tuning medium arranged in the gap region, so as to make the surface acoustic wave propagation speed of the electrode finger main region greater than the surface acoustic wave propagation speed of the electrode finger edge region.

[0028] In some embodiments, the material of the first velocity tuning medium is AlN, doped AlN, Si3N4, doped Si3N4, Al2O3, doped Al2O3, Qz, doped Qz, DLC, doped DLC, SiC or doped SiC.

[0029] In some embodiments, the substrate upper surface is provided with a first groove arranged corresponding to the electrode finger main region; the first velocity tuning medium is arranged in the first groove.

[0030] The substrate comprises a POI substrate; the first groove is arranged on the POI substrate.

[0031] Or, the substrate comprises a POI substrate and a Bragg reflector; the first groove is arranged on the Bragg reflector and located on the surface of the Bragg reflector facing away from the POI substrate.

[0032] In some embodiments, the material of the second velocity tuning medium is copper or aluminum.

[0033] In some embodiments, the substrate upper surface is provided with a second groove, and the second velocity tuning medium is at least partially arranged in the second groove.

[0034] The substrate comprises a POI substrate; the second groove is arranged on the POI substrate;

[0035] Alternatively, the substrate comprises a POI substrate and a Bragg reflector; the second groove is arranged on the Bragg reflector and is located on a surface of the Bragg reflector facing away from the POI substrate.

[0036] Embodiments of the present application also provide an electronic component comprising one or more surface acoustic wave resonators provided by embodiments of the present application.

[0037] Embodiments of the present application also provide an electronic device comprising:

[0038] A transceiver for receiving or transmitting a signal, the transceiver comprising an electronic component provided by embodiments of the present application;

[0039] A processor for signal processing of the signal, wherein the processor is coupled to the transceiver.

[0040] Embodiments of the present application also provide a method for manufacturing a surface acoustic wave resonator. The surface acoustic wave resonator comprises an electrode finger region and a gap region; the electrode finger region comprises an electrode finger main region and electrode finger edge regions located on both sides of the electrode finger main region along a first direction; along the first direction, the electrode finger region is provided with the gap region on both sides;

[0041] The method comprises:

[0042] Providing a substrate preliminary body;

[0043] Forming a first groove corresponding to the electrode finger main region on the upper surface of the substrate preliminary body, and forming a first speed-adjusting medium in the first groove; and / or forming a second speed-adjusting medium on the upper surface of the substrate preliminary body; the substrate has a substrate upper surface provided with the first speed-adjusting medium and / or the second speed-adjusting medium;

[0044] Forming a piezoelectric layer on the substrate upper surface; the piezoelectric layer has a piezoelectric layer upper surface facing away from the substrate; and

[0045] Forming an interdigital transducer on the piezoelectric layer upper surface, the interdigital transducer comprising two interdigital electrodes arranged opposite to each other along the first direction; each interdigital electrode comprises a bus bar and a plurality of electrode fingers extending along the first direction; the electrode fingers of the two interdigital electrodes overlap along the first direction in the electrode finger region; the region between the electrode fingers of one interdigital electrode and the bus bar of the other interdigital electrode is the gap region;

[0046] The first speed-adjusting medium is configured to make the surface acoustic wave propagation speed of the electrode finger main region greater than the surface acoustic wave propagation speed of the electrode finger edge region; and the second speed-adjusting medium is configured to make the surface acoustic wave propagation speed of the electrode finger main region greater than the surface acoustic wave propagation speed of the electrode finger edge region.

[0047] In some embodiments, the method further comprises:

[0048] forming a second groove on the upper surface of the substrate bulk; the second groove is located in the gap region;

[0049] the second speed-adjusting medium is at least partially arranged in the second groove.

[0050] In some embodiments, the speed-adjusting medium is arranged on the main region of the electrode finger and on the side of the piezoelectric layer facing the substrate, so that the propagation speed of the surface acoustic wave in the main region of the electrode finger is greater than the propagation speed of the surface acoustic wave in the edge region of the electrode finger, thereby inducing the piston mode in the main region of the electrode finger and suppressing the propagation of the transverse spurious wave, and thereby suppressing the transverse spurious phenomenon. BRIEF DESCRIPTION OF DRAWINGS

[0051] Fig. 1 shows a top view of a surface acoustic wave resonator according to an embodiment of the present application.

[0052] Fig. 2 shows a cross-sectional view along the M-M direction of the surface acoustic wave resonator shown in Fig. 1 and a corresponding distribution of the propagation speed of the acoustic wave.

[0053] Fig. 3 shows a cross-sectional view along the N-N direction of the surface acoustic wave resonator shown in Fig. 1.

[0054] Fig. 4 shows the effect of the change of the conductance with frequency when the thickness of the first speed-adjusting medium of the surface acoustic wave resonator shown in Fig. 1 is changed.

[0055] Fig. 5 shows the admittance characteristic curves when the thickness of the first speed-adjusting medium of the surface acoustic wave resonator shown in Fig. 1 is 0 and 20 nm.

[0056] Fig. 6 shows the effect of the change of the conductance with frequency when the width of the edge region of the electrode finger of the surface acoustic wave resonator shown in Fig. 1 is changed.

[0057] Fig. 7 shows the admittance characteristic curves when the width of the edge region of the electrode finger of the surface acoustic wave resonator shown in Fig. 1 is 0.2λ and 0.8λ, respectively.

[0058] Fig. 8 shows another cross-sectional view of a surface acoustic wave resonator according to an embodiment of the present application.

[0059] Fig. 9 shows another cross-sectional view of a surface acoustic wave resonator according to an embodiment of the present application.

[0060] Fig. 10 shows the effect of the change of the conductance with frequency when the thickness of the second speed-adjusting medium of the surface acoustic wave resonator shown in Fig. 9 is changed.

[0061] Fig. 11 shows the admittance characteristic curves of the SAW resonator shown in Fig. 8 when the thickness of the second velocity-modulating medium is 0 and 180 nm.

[0062] Fig. 12 shows another cross-sectional view of a SAW resonator according to an embodiment of the present application.

[0063] Fig. 13 shows another cross-sectional view of a SAW resonator according to an embodiment of the present application.

[0064] Fig. 14 shows another cross-sectional view of a SAW resonator according to an embodiment of the present application.

[0065] Fig. 15 shows the effect of the change of the conductance with frequency when the thickness of the second velocity-modulating medium is different in the SAW resonator shown in Fig. 14.

[0066] Fig. 16 shows the admittance characteristic curves of the SAW resonator shown in Fig. 14 when the thickness of the second velocity-modulating medium is 1 nm, 100 nm and 200 nm, respectively.

[0067] Fig. 17 shows the effect of the change of the conductance with frequency when the width of the second velocity-modulating medium is different in the SAW resonator shown in Fig. 14.

[0068] Fig. 18 shows a cross-sectional view of a SAW resonator substrate according to an embodiment of the present application.

[0069] Fig. 19 shows another cross-sectional view of a SAW resonator substrate according to an embodiment of the present application.

[0070] Fig. 20 shows another cross-sectional view of a SAW resonator substrate according to an embodiment of the present application.

[0071] Fig. 21 shows another cross-sectional view of a SAW resonator substrate according to an embodiment of the present application.

[0072] Fig. 22 shows a flowchart of a method for manufacturing a SAW resonator according to an embodiment of the present application.

[0073] Figs. 23a-23e show the structure of a SAW resonator at different stages of the manufacturing process according to an embodiment of the present application.

[0074] Reference signs: 100 / 200 / 300 / 400 / 500 / 600, surface acoustic wave resonator; 110m / 100n / 100p / 100q, surface acoustic wave resonator substrate; 110, substrate; 110a, POI substrate; 110b, Bragg reflector; 111, semiconductor layer; 1111, single crystal silicon layer; 1113, polycrystalline silicon layer; 113, insulating layer; 113a, insulating layer initial layer; 1131, substrate upper surface; 112, first groove; 114, second groove; 120, piezoelectric layer; 121, third groove; 122, piezoelectric layer upper surface; 124, piezoelectric layer lower surface; 130, interdigital transducer; 131, interdigital electrode; 132, busbar; 134, electrode finger; 136, dummy finger; 140, velocity tuning medium; 141, first velocity tuning medium; 142, second velocity tuning medium; m-m, first direction; n-n, second direction; a, busbar region; b, gap region; c, electrode finger region; d, electrode finger main region; e, electrode finger edge region; 01, substrate initial body. DETAILED DESCRIPTION

[0075] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments.

[0076] The meaning of "on" in the present application should be interpreted in the broadest way, so that "on" not only means "directly on", but also means "on" including the presence of intermediate components or layers between them.

[0077] The orientations or positional relationships indicated by "center", "longitudinal", "lateral", "length", "width", "thickness", "height", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like in the present application are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of simplifying the present application, and cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, that is, cannot be understood as a limitation on the present application.

[0078] The "first", "second" in the present application are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the present application, the meaning of "several", "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0079] As used herein, the term "layer" refers to a portion of material that includes a region having a thickness. A layer can extend over an entire underlying or overlying structure, or can have an area less than the area of the underlying or overlying structure. Further, a layer can be a region of a homogenous or inhomogenous continuous structure that has a thickness less than the thickness of the continuous structure. For example, a layer can be between the top surface and the bottom surface of a continuous structure or between any pair of horizontal planes within the same. Layers can extend horizontally, vertically, and / or along a tapered surface. Layers can include multiple layers. For example, a semiconductor layer can include one or more doped or undoped semiconductor layers and can be of the same or different materials.

[0080] In the related art, the inventors found that part of the surface acoustic wave has a certain angle between the wave vector and the main propagation direction in the actual propagation, which also means that the surface acoustic wave not only propagates along the main direction, but also propagates in the transverse direction, by analyzing the cause of the transverse mode surface acoustic wave. Based on the above analysis, the inventors propose a surface acoustic wave resonator capable of effectively suppressing the transverse propagation of the surface acoustic wave in the resonator.

[0081] Specifically, a speed adjustment medium is arranged below the electrode finger main area of the piezoelectric layer, so that the surface acoustic wave propagation speed of the electrode finger main area is greater than the surface acoustic wave propagation speed of the electrode finger edge area, so as to induce a piston mode in the electrode finger main area, realize the suppression of the propagation of the transverse stray wave, and suppress the transverse stray phenomenon.

[0082] Referring to FIGS. 1-3, a surface acoustic wave resonator 100 according to an embodiment of the present application is shown. The surface acoustic wave resonator 100 includes a substrate 110, a piezoelectric layer 120 disposed on the substrate 110, an interdigital transducer 130, and a speed adjustment medium 140.

[0083] Specifically, the piezoelectric layer 120 has a piezoelectric layer upper surface 122 facing away from the substrate 110. The interdigital transducer 130 is located on the piezoelectric layer upper surface 122. The interdigital transducer 130 includes two interdigital electrodes 131 disposed on the piezoelectric layer 120 opposite each other along a first direction m-m. Each interdigital electrode 131 includes a bus bar 132 and a plurality of electrode fingers 134 extending along the first direction m-m. It can be understood that FIG. 1 only schematically shows that each interdigital electrode 131 includes one electrode finger 134. In a specific implementation, each interdigital electrode 131 can include a plurality of electrode fingers 134. The overlapping area of the electrode fingers 134 of the two interdigital electrodes 131 along the first direction m-m is an electrode finger area c.

[0084] It can be understood that, referring to FIG. 1 to FIG. 3, the electrode finger region c corresponds to a portion where the electrode fingers 134 of the two interdigital electrodes 131 overlap along the first direction m-m. Moreover, the electrode finger region c of the surface acoustic wave resonator extends along the second direction n-n, and the extension length is at least equal to the length of the interdigital transducer 130 along the second direction n-n. The second direction n-n is the direction in which the electrode fingers 134 of the interdigital transducer 130 are arranged. The second direction n-n intersects the first direction m-m.

[0085] The electrode finger region c includes an electrode finger main region d and electrode finger edge regions e located on both sides of the electrode finger main region d along the first direction m-m. It can be understood that the electrode finger region c extends along the second direction n-n, and the extension length is at least equal to the length of the interdigital transducer 130 along the second direction n-n. It can be understood that the extension length of the electrode finger main region d and the electrode finger edge regions e in the electrode finger region c along the second direction n-n is at least equal to the length of the interdigital transducer 130 along the second direction n-n.

[0086] The region between the electrode fingers 134 of one interdigital electrode 131 and the bus bar 132 of the other interdigital electrode 131 is a gap region b. It can be understood that the gap region b is provided on both sides of the electrode finger region c. Similarly, the extension length of the gap region b along the second direction n-n is also at least equal to the length of the interdigital transducer 130 along the second direction n-n.

[0087] The speed adjustment medium 140 is located on the side of the piezoelectric layer 120 facing the substrate 110. The speed adjustment medium 140 includes a first speed adjustment medium 141 arranged corresponding to the electrode finger main region d, for making the surface acoustic wave propagation speed of the electrode finger main region greater than the surface acoustic wave propagation speed of the electrode finger edge region.

[0088] The speed adjustment medium 140 is used to make the surface acoustic wave propagation speed of the electrode finger main region d greater than the surface acoustic wave propagation speed of the electrode finger edge region e, so as to induce a piston mode in the electrode finger main region d, to suppress the propagation of the transverse spurious wave, suppress the transverse spurious phenomenon, and thus improve the frequency selectivity of the surface acoustic wave resonator, reduce the insertion loss, increase the signal purity, and facilitate signal processing and filtering effect in the communication system and other applications.

[0089] The first speed adjustment medium 141 is located on the bottom side of the piezoelectric layer 120. The first speed adjustment medium 141 and the interdigital transducer 130 are respectively located on both sides of the piezoelectric layer 120, so the arrangement of the first speed adjustment medium 141 has no effect on the structure of the interdigital transducer 130, that is, the suppression of the transverse spurious phenomenon is achieved without changing the structure of the interdigital transducer 130.

[0090] The interdigital electrodes 131 can be, but are not limited to, composed of Ti, Al, Cu, Au, Pt, Ag, Pd, Ni, or an alloy thereof, or a laminate of these metals or alloys.

[0091] Optionally, the piezoelectric layer 120 can be, but is not limited to, a 50YX° lithium tantalate layer, a lithium niobate layer, a lithium tantalate layer, a quartz layer, an aluminum nitride layer, or a zinc oxide layer.

[0092] Referring to FIG. 1, the first direction m-m is perpendicular to the second direction n-n. It can be understood that in another possible embodiment, the first direction m-m and the second direction n-n are not limited to be perpendicular, but can be intersected.

[0093] It can be understood that the surface acoustic wave resonator is not limited to include one interdigital transducer. When the surface acoustic wave resonator includes a plurality of interdigital transducers, each interdigital transducer corresponds to a set of gap regions b, electrode finger edge regions e, electrode finger main regions d, electrode finger edge regions e, and gap regions b arranged in the first direction m-m in sequence.

[0094] It should be noted that in the present application, the first direction m-m refers to the direction of arrangement of the two interdigital electrodes 131 in the corresponding interdigital transducer 130. If the surface acoustic wave resonator includes a plurality of interdigital transducers 130, the first direction m-m corresponding to different interdigital transducers 130 can be different.

[0095] In the present embodiment, the substrate 110 has a substrate upper surface 1131 facing the piezoelectric layer 120, and the substrate upper surface 1131 is provided with a first recess 112 corresponding to the electrode finger main regions d; the first velocity adjustment medium 141 is arranged in the first recess 112.

[0096] It can be understood that the first velocity adjustment medium 141 is filled in the first recess 112 and is attached to the piezoelectric layer 120. The thickness of the first velocity adjustment medium 141 is equal to the depth of the first recess 112.

[0097] The first velocity adjustment medium 141 is arranged in the first recess 112 of the substrate 110, so that the arrangement of the first velocity adjustment medium 141 does not increase the thickness of the surface acoustic wave resonator, i.e., does not change the size of the surface acoustic wave resonator. That is, the suppression of the transverse dispersion phenomenon is achieved without increasing the thickness of the surface acoustic wave.

[0098] In this embodiment, the acoustic impedance of the first speed adjustment medium 141 is greater than the acoustic impedance of the piezoelectric layer 120. Thus, the acoustic surface wave propagation speed of the first speed adjustment medium 141 is greater than the acoustic surface wave propagation speed of the piezoelectric layer 120. Because the first speed adjustment medium 141 is in direct mechanical contact with the piezoelectric layer 120, multiple reflections generated from the first speed adjustment medium 141 increase the speed of the acoustic surface wave in the piezoelectric layer 120, and further increase the propagation speed of the electrode finger main region d, and further make the acoustic surface wave propagation speed of the electrode finger main region d greater than the acoustic surface wave propagation speed of the electrode finger edge region e.

[0099] The material of the first speed adjustment medium 141 can be, but is not limited to, AlN, doped AlN, Si3N4, doped Si3N4, Al2O3, doped Al2O3, Qz (Quartz mineral), doped Qz, DLC (Diamond-like Carbon), doped DLC, SiC, or doped SiC.

[0100] Optionally, the thickness h1 of the first speed adjustment medium 141 is in the range of 10 nm to 40 nm, which can better suppress the propagation of the transverse spurious wave, suppress the transverse spurious phenomenon, and make the acoustic surface wave resonator have a larger bandwidth, so as to be able to maintain a relatively high energy transmission efficiency in a wider frequency range. For example, the thickness h1 of the first speed adjustment medium 141 can be 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, or 40 nm.

[0101] Referring to FIG. 4, the effect of the change of the conductance with the frequency is different when the thickness h1 of the first speed adjustment medium 141 is different. Therefore, the thickness h1 of the first speed adjustment medium 141 affects the effect of the change of the conductance with the frequency of the acoustic surface wave resonator, i.e., can affect the admittance characteristics of the acoustic surface wave resonator, and the suppression effect of the transverse spurious is different.

[0102] Specifically, referring to FIG. 4, in the acoustic surface wave resonator 100, the material of the piezoelectric layer 120 is 50°YX LT (50°YX lithium tantalate), and the material of the first speed adjustment medium 141 is AlN. That is, in the case where other parameters are the same, only the thickness h1 of the first speed adjustment medium 141 is changed. According to the curve in FIG. 4, when the thickness h1 of the first speed adjustment medium 141 is in the range of 10 nm to 40 nm, the resonance peak is relatively sharp, and the curve is relatively smooth, and the suppression effect of the transverse spurious is better.

[0103] Optionally, the thickness h1 of the first speed-adjusting medium 141 is 20 nm. Referring to FIG. 5, the curve L1 is the admittance curve when the thickness h1 of the first speed-adjusting medium 141 is 20 nm, and the curve L2 is the admittance curve when the thickness h1 of the first speed-adjusting medium 141 is 0. As shown in FIG. 5, when the thickness h1 of the first speed-adjusting medium 141 is 0, the curve between the resonance point and the anti-resonance point is relatively not smooth, and there are more resonance peaks, and the suppression effect on the transverse stray mode is poor. When the thickness h1 of the first speed-adjusting medium 141 is 20 nm, the curve between the resonance point and the anti-resonance point is relatively smooth, and there are fewer resonance peaks, and the suppression effect on the transverse stray mode is good, so that the surface acoustic wave resonator can have a larger bandwidth, thereby being able to maintain a relatively high energy transmission efficiency in a wider frequency range.

[0104] Optionally, the width w1 of the electrode finger edge region e along the first direction m-m is in the range of 0.2λ-2λ, where λ is the wavelength of the surface acoustic wave resonator, so that the propagation of the transverse stray wave can be better suppressed, and the transverse stray phenomenon can be better suppressed. For example, the width w1 of the electrode finger edge region e along the first direction m-m is 0.2λ, 0.5λ, 0.7λ, 1λ, 1.2λ, 1.5λ, 1.7λ or 2λ.

[0105] Referring to FIG. 6, the effect of the conductance changing with the frequency is different when the width w1 of the electrode finger edge region e is different. Therefore, the width w1 of the electrode finger edge region e affects the effect of the conductance of the surface acoustic wave resonator changing with the frequency, that is, affects the admittance characteristics of the surface acoustic wave resonator, and the suppression effect on the transverse stray is different.

[0106] Specifically, referring to FIG. 6, in the surface acoustic wave resonator, the material of the first speed-adjusting medium 141 is AlN, the material of the piezoelectric layer 120 is 50°YX lithium tantalate, and the thickness h1 of the first speed-adjusting medium 141 is 20 nm. That is, in the case where other parameters are the same, only the width w1 of the electrode finger edge region e is changed. As shown in the curve in FIG. 6, when the width w1 of the electrode finger edge region e is 0.8λ, the resonance peak is relatively sharp, and the curve is relatively smooth, and the suppression effect on the transverse stray is good.

[0107] Optionally, the width w1 of the electrode finger edge region e along the first direction m-m is 0.8λ. Referring to FIG. 7, the curve L1 is the admittance curve when the width w1 of the electrode finger edge region e is 0.2λ, and the curve L2 is the admittance curve when the width w1 of the electrode finger edge region e is 0.8λ. As shown in FIG. 7, when the width w1 of the electrode finger edge region e is 0.2λ, the curve between the resonance point and the anti-resonance point is relatively not smooth, and there are more resonance peaks, and the suppression effect on the transverse spurious mode is poor. When the width w1 of the electrode finger edge region e is 0.8λ, the curve between the resonance point and the anti-resonance point is relatively smooth, and there are fewer resonance peaks, and the suppression effect on the transverse spurious mode is good, so that the surface acoustic wave resonator can have a larger bandwidth, thereby being able to maintain a relatively high energy transmission efficiency in a wider frequency range.

[0108] Referring to FIGS. 2 and 3, the substrate 110 includes a POI substrate 110a. The first groove 112 is arranged on the POI substrate 110a. Specifically, the POI substrate 110a includes a semiconductor layer 111 and an insulating layer 113 arranged on the semiconductor layer 111. The upper surface 1131 of the substrate is the surface of the insulating layer 113 facing away from the semiconductor layer 111. It can be understood that the insulating layer 113 is used to separate the piezoelectric layer 120 from the semiconductor layer 111 to ensure good electrical insulation performance, so the depth of the first groove 112 is less than the depth of the insulating layer 113.

[0109] Optionally, the insulating layer 113 is a SiO2 layer. Of course, it can be understood that in another feasible embodiment, the insulating layer 113 is not limited to the SiO2 layer, but is formed of other insulating materials.

[0110] Referring to FIGS. 2 and 3, in this embodiment, the semiconductor layer 111 includes a single crystal silicon layer 1111 and a polycrystalline silicon layer 1113 arranged on the single crystal silicon layer 1111. Of course, it can be understood that in another embodiment, the structure of the semiconductor layer is not limited thereto, and can be set according to conventional selection in the art.

[0111] Referring to FIG. 1, the interdigital electrode 131 further includes a plurality of dummy fingers 136. The dummy fingers 136 are connected with the bus bar 132 and extend along the first direction m-m. The plurality of electrode fingers 134 and the plurality of dummy fingers 136 in the same interdigital electrode 131 are alternately arranged along the second direction n-n. The dummy fingers 136 of one interdigital electrode 131 are arranged opposite to the electrode fingers 134 of another interdigital electrode 131 with a gap. The arrangement of the dummy fingers 136 can also suppress the propagation of the transverse spurious wave to a certain extent, thereby better suppressing the transverse spurious phenomenon. Of course, it can be understood that in another embodiment, the interdigital electrode can also not be provided with the dummy fingers.

[0112] Referring to FIG. 8, the SAW resonator 200 is provided according to another embodiment of the present application. Different from the SAW resonator 100, the substrate 110 includes a POI substrate 110a and a Bragg reflector 110b, the Bragg reflector is located between the POI substrate and the piezoelectric layer 120, and the first recess 112 is arranged on the Bragg reflector 110b. Similarly, the first velocity-modifying medium 141 is located in the first recess 112 and is attached to the piezoelectric layer 120, i.e., is embedded in the Bragg reflector 110b, so that the arrangement of the first velocity-modifying medium 141 does not increase the thickness of the SAW resonator, i.e., does not change the size of the SAW resonator. That is, the suppression of the lateral spurious phenomenon is achieved without increasing the thickness of the SAW resonator.

[0113] Referring to FIG. 9, the SAW resonator 300 is provided according to another embodiment of the present application. Different from the SAW resonator 100, the velocity-modifying medium 140 further includes a second velocity-modifying medium 142 located in the gap region b.

[0114] The first velocity-modifying medium 141 and the second velocity-modifying medium 142 jointly act to more greatly adjust the SAW propagation speed of the electrode finger main region and the SAW propagation speed of the electrode finger edge region, and thus more effectively suppress the propagation of the spurious wave and the lateral spurious phenomenon.

[0115] Optionally, the density of the second velocity-modifying medium 142 is greater than the density of the piezoelectric layer 120. Thus, the second velocity-modifying medium 142 can form a mass load of the piezoelectric layer 120, and thus reduce the SAW speed of the gap region b. And, affected by the second velocity-modifying medium 142, the SAW speed of the electrode finger edge region e adjacent to the gap region b is also reduced. Thus, the SAW propagation speed of the electrode finger main region d is more effectively ensured to be greater than the SAW propagation speed of the electrode finger edge region e, and thus the piston mode is induced in the electrode finger main region d, the propagation of the lateral spurious wave is suppressed, the lateral spurious phenomenon is suppressed, the frequency selectivity of the SAW resonator is improved, the insertion loss is reduced, the signal purity is increased, and the signal processing and filtering effect in the communication system and other applications is facilitated.

[0116] Optionally, the material of the second velocity-modifying medium 142 can be, but is not limited to, copper or aluminum, and the density of the second velocity-modifying medium 142 is only required to be greater than the density of the piezoelectric layer 120.

[0117] Optionally, the thickness h2 of the second velocity-tuning medium 142 is in the range of 20nm to 200nm, which can better suppress the propagation of the transverse spurious wave, suppress the transverse spurious phenomenon, and make the SAW resonator have a larger bandwidth, so as to maintain a relatively high energy transmission efficiency in a wider frequency range. For example, the thickness h2 of the second velocity-tuning medium 142 can be 20nm, 30nm, 50nm, 70nm, 90nm, 100nm, 120nm, 140nm, 150nm, 170nm, 190nm or 200nm.

[0118] Referring to FIG. 10, the effect of the change of the conductance with frequency is different when the thickness h2 of the second velocity-tuning medium 142 is different. Therefore, the thickness of the second velocity-tuning medium 142 affects the effect of the change of the conductance with frequency of the SAW resonator 300, i.e. affects the admittance characteristics of the SAW resonator 300, and the suppression effect on the transverse spurious is different. Optionally, the thickness h2 of the second velocity-tuning medium 142 is 180nm.

[0119] Referring to FIG. 11, the curve L1 is the admittance curve when the thickness h2 of the second velocity-tuning medium 142 is 0nm, and the curve L2 is the admittance curve when the thickness h2 of the second velocity-tuning medium 142 is 180nm. As can be seen from FIG. 11, when the thickness h2 of the second velocity-tuning medium 142 is 0nm, the curve between the resonance point and the anti-resonance point is relatively not smooth, there are more resonance peaks, and the suppression effect on the transverse spurious mode is poor. When the thickness h2 of the second velocity-tuning medium 142 is 180nm, the curve between the resonance point and the anti-resonance point is relatively smooth, there are fewer resonance peaks, and the suppression effect on the transverse spurious mode is good, so that the SAW resonator can have a larger bandwidth, so as to maintain a relatively high energy transmission efficiency in a wider frequency range.

[0120] Specifically, referring to FIG. 9, the substrate 110 has a substrate upper surface 1131 facing the piezoelectric layer 120, and the substrate upper surface 1131 of the substrate 110 is provided with a second groove 114, and the second velocity-tuning medium 142 is arranged in the second groove 114. Therefore, the arrangement of the second velocity-tuning medium 142 also does not increase the thickness of the SAW resonator and does not change the size of the SAW resonator.

[0121] More specifically, the second groove 114 is arranged on the insulating layer 113 of the substrate 110. Obviously, the depth of the second groove 114 is less than the thickness of the insulating layer 113.

[0122] In the embodiment shown in FIG. 9, the width of the second velocity-tuning medium 142 along the first direction m-m is equal to the width of the gap region b. It should be noted that in another embodiment, the width of the second velocity-tuning medium 142 along the first direction m-m can also be less than the width of the gap region b.

[0123] Referring to FIG. 12, the surface acoustic wave resonator 400 provided by another embodiment of the present application is different from the surface acoustic wave resonator 300 in that the piezoelectric layer 120 has a piezoelectric layer lower surface 124 facing the substrate 110, and the piezoelectric layer lower surface 124 is provided with a third groove 121, and the second velocity-adjusting medium 142 is arranged in the third groove 121. Thus, the arrangement of the second velocity-adjusting medium 142 does not increase the thickness of the surface acoustic wave resonator 400, nor change the size of the surface acoustic wave resonator 400.

[0124] It can be understood that the depth of the third groove 121 is not limited to being less than the thickness of the piezoelectric layer 120, but can also be equal to the thickness of the piezoelectric layer 120.

[0125] It can be understood that in another embodiment, a second groove can be arranged on the substrate upper surface of the substrate, and a third groove can be arranged on the piezoelectric layer lower surface of the piezoelectric layer. The second velocity-adjusting medium is partially arranged in the second groove and partially arranged in the third groove. It can be understood that the sum of the depth of the second groove and the depth of the third groove is equal to the thickness of the second velocity-adjusting medium.

[0126] Referring to FIG. 13, the surface acoustic wave resonator 500 provided by another embodiment of the present application is different from the surface acoustic wave resonator 400 in that each gap region b has a plurality of second velocity-adjusting media 142, and the plurality of second velocity-adjusting media 142 are arranged at intervals along the first direction m-m.

[0127] Among the plurality of second velocity-adjusting media 142, the width of different second velocity-adjusting media 142 along the first direction m-m can be the same or different. Similarly, the thickness h2 of different second velocity-adjusting media 142 can be the same or different.

[0128] It can be understood that the number of second velocity-adjusting media 142 in different gap regions b can be the same or different.

[0129] In addition, in the present embodiment, when each gap region b includes three or more second velocity-adjusting media 142, the distance between adjacent second velocity-adjusting media 142 can be the same or different.

[0130] Furthermore, the materials of different second velocity-adjusting media 142 can be the same or different.

[0131] Referring to FIG. 14, the SAW resonator 600 provided by another embodiment of the present application is different from the SAW resonator 300 in that the velocity-adjusting medium 140 only includes the second velocity-adjusting medium 142, the propagation velocity of the SAW at the electrode finger edge region e is reduced by the second velocity-adjusting medium 142, and then the propagation velocity of the SAW at the electrode finger main region d is greater than the propagation velocity of the SAW at the electrode finger edge region e, so as to induce the piston mode in the electrode finger main region d, to realize the suppression of the propagation of the transverse spurious wave, to suppress the transverse spurious phenomenon, to further improve the frequency selectivity of the SAW resonator, to reduce the insertion loss, to increase the signal purity, and to be beneficial to the signal processing and filtering effect in the communication system and other applications.

[0132] The position of the second velocity-adjusting medium 142 is set as described above with reference to the setting of the second velocity-adjusting medium 142 in the SAW resonator 300, and will not be described herein again.

[0133] Optionally, the thickness h2 of the second velocity-adjusting medium 142 is within the range of 20 nm to 200 nm, which can better suppress the propagation of the transverse spurious wave, suppress the transverse spurious phenomenon, and make the SAW resonator have a larger bandwidth, so as to be able to maintain a relatively high energy transmission efficiency within a wider frequency range. For example, the thickness h2 of the second velocity-adjusting medium 142 can be 20 nm, 30 nm, 50 nm, 70 nm, 90 nm, 100 nm, 120 nm, 140 nm, 150 nm, 160 nm, 170 nm, 180 nm, 190 nm, or 200 nm.

[0134] Referring to FIG. 15, the thickness h2 of the second velocity-adjusting medium 142 is m2_h in FIG. 15, and the arrangement order of the multiple conductance curves from the upper right to the lower left is consistent with the arrangement order of the thickness from the upper right to the lower left in FIG. 15. When the thickness h2 of the second velocity-adjusting medium 142 is different, the effect of the change of the conductance with the frequency is different. Therefore, the thickness of the second velocity-adjusting medium 142 affects the effect of the change of the conductance with the frequency of the SAW resonator 300, that is, affects the conductance characteristics of the SAW resonator 300, and the suppression effect on the transverse spurious is different. Optionally, the thickness h2 of the second velocity-adjusting medium 142 is 100 nm.

[0135] Specifically, referring to FIG. 15, in the SAW resonator, the material of the second velocity-adjusting medium 142 is Cu. That is, under the condition that other parameters are the same, only the thickness h2 of the second velocity-adjusting medium 142 is changed. According to the curve in FIG. 15, when the thickness h2 of the second velocity-adjusting medium 142 is within the range of 20 nm to 200 nm, the resonance peak is relatively sharp, the curve is relatively smooth, and the suppression effect on the transverse spurious is better.

[0136] Referring to FIG. 16, curve L1 is a conductance curve when the thickness h2 of the second speed adjustment medium 142 is 1 nm, curve L2 is a conductance curve when the thickness h2 of the second speed adjustment medium 142 is 100 nm, and curve L3 is a conductance curve when the thickness h2 of the second speed adjustment medium 142 is 200 nm. As can be seen from FIG. 16, when the thickness h2 of the second speed adjustment medium 142 is 1 nm and 200 nm, the curve between the resonance point and the anti-resonance point is relatively not smooth, there are many resonance peaks, and the suppression effect on the transverse stray mode is poor. When the thickness h2 of the second speed adjustment medium 142 is 100 nm, the curve between the resonance point and the anti-resonance point is relatively smooth, there are fewer resonance peaks, and the suppression effect on the transverse stray mode is good, so that the surface acoustic wave resonator can have a large bandwidth, thereby being able to maintain a relatively high energy transmission efficiency in a relatively wide frequency range.

[0137] Optionally, the width W2 of the second speed adjustment medium 142 along the first direction m-m is in the range of 0.4λ-1λ, which can better suppress the propagation of the transverse stray wave, suppress the transverse stray phenomenon, and make the surface acoustic wave resonator have a large bandwidth, thereby being able to maintain a relatively high energy transmission efficiency in a relatively wide frequency range. Wherein λ is the wavelength of the surface acoustic wave resonator. For example, the width W2 of the second speed adjustment medium 142 can be 0.4λ, 0.45λ, 0.5λ, 0.55λ, 0.60λ, 0.65λ, 0.7λ, 0.75λ, 0.8λ, 0.85λ, 0.9λ, 0.95λ or 1λ. Optionally, the width W2 of the second speed adjustment medium 142 is 0.6λ.

[0138] Referring to FIG. 17, the width W2 of the second speed adjustment medium 142 is m2_l in FIG. 17, and the arrangement order of the plurality of conductance curves from the upper right to the lower left is consistent with the arrangement order of the widths listed from the upper right to the lower left of the figure. When the width W2 of the second speed adjustment medium 142 is different, the effect of the conductance changing with the frequency is different. Therefore, the width W2 of the second speed adjustment medium 142 affects the effect of the conductance of the surface acoustic wave resonator changing with the frequency, that is, affects the conductance characteristics of the surface acoustic wave resonator, and the suppression effect on the transverse stray is different.

[0139] Specifically, referring to FIG. 17, in the surface acoustic wave resonator, the material of the second speed adjustment medium 142 is copper, and the thickness h1 of the second speed adjustment medium 142 is 100 nm. That is, under the condition that other parameters are the same, only the width W2 of the second speed adjustment medium 142 is changed. As can be seen from the curves in FIG. 17, when the width W2 of the second speed adjustment medium 142 is 0.6λ, the resonance peak is relatively sharp, and the curve is relatively smooth, and the suppression effect on the transverse stray is good.

[0140] It can be understood that, in another possible embodiment, in the case that the speed-adjusting medium comprises the second speed-adjusting medium but not the first speed-adjusting medium, the arrangement of the second speed-adjusting medium is not limited to this, and the second speed-adjusting medium can also be embedded in the piezoelectric layer, and the arrangement of the second speed-adjusting medium in the surface acoustic wave resonator 400 can be referred to. A plurality of spaced second speed-adjusting media can also be arranged in each gap region, and the arrangement of the second speed-adjusting medium in the surface acoustic wave resonator 500 can be referred to.

[0141] Referring to FIG. 18, the surface acoustic wave resonator substrate 110m provided by an embodiment of the present application is shown. The surface acoustic wave resonator substrate 110m comprises an electrode finger region c and a gap region b; the electrode finger region c comprises an electrode finger main region d and electrode finger edge regions e located on both sides of the electrode finger main region d along a first direction m-m; the gap region b is arranged on both sides of the electrode finger region c along the first direction m-m.

[0142] The surface acoustic wave resonator substrate 100m comprises a substrate 110 and a speed-adjusting medium 140. The substrate 110 has a substrate upper surface 1131. The speed-adjusting medium 140 is arranged on the substrate upper surface 1131, and the speed-adjusting medium 140 comprises a first speed-adjusting medium 141 arranged corresponding to the electrode finger main region d, for making the surface acoustic wave propagation speed of the electrode finger main region d greater than the surface acoustic wave propagation speed of the electrode finger edge region e.

[0143] The surface acoustic wave resonator substrate 110m described above, the speed-adjusting medium 140 is used to make the surface acoustic wave propagation speed of the electrode finger main region d greater than the surface acoustic wave propagation speed of the electrode finger edge region e, so as to induce a piston mode in the electrode finger main region d, to realize the suppression of the propagation of the transverse spurious wave, to suppress the transverse spurious phenomenon, and to further improve the frequency selectivity of the surface acoustic wave resonator, to reduce the insertion loss, to increase the signal purity, and to be beneficial to the signal processing and filtering effect in the communication system and other applications.

[0144] Optionally, the material of the first speed-adjusting medium 141 can be, but is not limited to, AlN, doped AlN, Si3N4, doped Si3N4, Al2O3, doped Al2O3, Qz, doped Qz, DLC, doped DLC, SiC or doped SiC. The first speed-adjusting medium 141 has a relatively large acoustic impedance, and can be matched with a piezoelectric layer formed by a piezoelectric material with a relatively small acoustic impedance, so as to make the surface acoustic wave propagation speed of the first speed-adjusting medium 141 greater than the surface acoustic wave propagation speed of the piezoelectric layer.

[0145] In the embodiment, the substrate upper surface 1131 is provided with a first recess 112 arranged corresponding to the electrode finger main region d; and the first speed-adjusting medium 141 is arranged in the first recess 112.

[0146] More specifically, the substrate 110 comprises a POI substrate 110a; and the first recess 112 is arranged on the POI substrate 110a.

[0147] It can be understood that the surface of the POI substrate 110a on which the first recess 112 is arranged, i.e., the upper surface 1131 of the substrate, is used to form a piezoelectric layer, so that the first speed adjustment medium 141 is in mechanical contact with the piezoelectric layer. Multiple reflections generated from the first speed adjustment medium 141 make the speed of the surface acoustic wave increase in the piezoelectric layer, thereby increasing the propagation speed of the electrode finger main region d, and thereby making the surface acoustic wave propagation speed of the electrode finger main region d greater than the surface acoustic wave propagation speed of the electrode finger edge region e.

[0148] Specifically, the POI substrate 110a, referring to the arrangement of the POI substrate 110a in the surface acoustic wave resonator 100, will not be described here.

[0149] Referring to FIG. 19, the surface acoustic wave resonator substrate 110n provided by an embodiment of the present application is different from the surface acoustic wave resonator substrate 110m in that the surface acoustic wave resonator substrate 110n includes a POI substrate 110a and a Bragg reflector 110b; the first recess 112 is arranged on the Bragg reflector 110b and is located on the surface of the Bragg reflector 110b facing away from the POI substrate 110a.

[0150] It can be understood that the surface of the Bragg reflector 110b facing away from the POI substrate 110a, i.e., the upper surface 1131 of the substrate, is used to form a piezoelectric layer, so that the first speed adjustment medium 141 is in mechanical contact with the piezoelectric layer. Multiple reflections generated from the first speed adjustment medium 141 make the speed of the surface acoustic wave increase in the piezoelectric layer, thereby increasing the propagation speed of the electrode finger main region d, and thereby making the surface acoustic wave propagation speed of the electrode finger main region d greater than the surface acoustic wave propagation speed of the electrode finger edge region e.

[0151] Referring to FIG. 20, the surface acoustic wave resonator substrate 110p provided by an embodiment of the present application is different from the surface acoustic wave resonator substrate 110m in that the speed adjustment medium 140 includes a second speed adjustment medium 142 located in the gap region b, which is used to make the surface acoustic wave propagation speed of the electrode finger main region d greater than the surface acoustic wave propagation speed of the electrode finger edge region e.

[0152] Optionally, the material of the second speed adjustment medium 142 is copper or aluminum.

[0153] The second velocity tuning medium 142 has a large density, and can be matched with the piezoelectric layer formed by the piezoelectric material with a small density, so that the surface acoustic wave propagation speed of the second velocity tuning medium 142 is greater than the surface acoustic wave propagation speed of the piezoelectric layer. Specifically, the second velocity tuning medium 142 can form a mass load of the piezoelectric layer, thereby reducing the surface acoustic wave speed of the gap region b. And, affected by the second velocity tuning medium 142, the surface acoustic wave speed of the electrode finger edge region e adjacent to the gap region b is also reduced, so that the surface acoustic wave propagation speed of the electrode finger main region d is greater than the surface acoustic wave propagation speed of the electrode finger edge region e, thereby inducing a piston mode in the electrode finger main region d, suppressing the propagation of the transverse spurious wave, suppressing the transverse spurious phenomenon, thereby improving the frequency selectivity of the surface acoustic wave resonator, reducing the insertion loss, increasing the signal purity, and facilitating signal processing and filtering effect in the communication system and other applications.

[0154] In the embodiment, the second groove 114 is arranged on the upper surface 1131 of the substrate, and the second velocity tuning medium 142 is arranged in the second groove 114.

[0155] More specifically, in the embodiment, the substrate 110 includes a POI substrate 110a, and the second groove 114 is arranged on the POI substrate 110a. Similarly, the POI substrate 110a is arranged as described above with reference to the POI substrate 110a in the surface acoustic wave resonator 100, and details are not repeated here.

[0156] It can be understood that the surface of the POI substrate 110a on which the second groove 114 is arranged, i.e., the upper surface 1131 of the substrate, is used to form a piezoelectric layer, so that the second velocity tuning medium 142 is in mechanical contact with the piezoelectric layer, and the second velocity tuning medium 142 can form a mass load of the piezoelectric layer, thereby reducing the surface acoustic wave speed of the gap region.

[0157] In the embodiment, the second velocity tuning medium 142 is arranged in the second groove 114. And, along the thickness direction of the substrate 110, i.e., the up-down direction in FIG. 20, the height of the second velocity tuning medium 142 is equal to the depth of the second groove 114. It can be understood that in another feasible embodiment, the height of the second velocity tuning medium 142 can also be greater than the depth of the second groove 114, i.e., the second velocity tuning medium 142 is arranged in the second groove 114 and protrudes from the upper surface 1131 of the substrate.

[0158] In the embodiment, one second velocity tuning medium 142 is arranged corresponding to each gap region b. It can be understood that in another feasible embodiment, two or more second velocity tuning media 142 can also be arranged corresponding to each gap region b, and the second velocity tuning media 142 are arranged along the first direction m-m, as described above with reference to the arrangement of the second velocity tuning medium 142 in the surface acoustic wave resonator 500.

[0159] Referring to FIG. 21, the SAW resonator substrate 110q provided by an embodiment of the present application is different from the SAW resonator substrate 110p in that the substrate 110 includes a POI substrate 110a and a Bragg reflector 110b; and the second recess 114 is arranged on the Bragg reflector 110b and located on a surface of the Bragg reflector 110b facing away from the POI substrate 110a.

[0160] It can be understood that the surface 110b of the Bragg reflector 110b facing away from the POI substrate, i.e., the upper surface 1131 of the substrate, is used to form a piezoelectric layer, so that the second velocity-adjusting medium 142 is in mechanical contact with the piezoelectric layer, and the second velocity-adjusting medium 142 can form a mass load of the piezoelectric layer, thereby reducing the surface acoustic wave velocity in the gap region.

[0161] It can be understood that in another possible embodiment, the position of the substrate 110 where the second velocity-adjusting medium 142 is arranged can also not be provided with the second recess 114, i.e., the second velocity-adjusting medium 142 is directly arranged on the upper surface 1131 of the substrate.

[0162] It can be understood that in another possible embodiment, the velocity-adjusting medium can also include the first velocity-adjusting medium and the second velocity-adjusting medium at the same time.

[0163] An electronic component is provided by an embodiment of the present application, which includes the SAW resonator provided by the present application.

[0164] The SAW resonator of the electronic component described above is configured to set the velocity-adjusting medium on the electrode finger main region and on the side of the piezoelectric layer facing the substrate, so that the surface acoustic wave propagation velocity of the electrode finger main region is greater than the surface acoustic wave propagation velocity of the electrode finger edge region, to induce the piston mode in the electrode finger main region, to suppress the propagation of the transverse spurious wave, to suppress the transverse spurious phenomenon, and to further improve the frequency selectivity of the SAW resonator, to reduce the insertion loss, to increase the signal purity, and to be beneficial to the signal processing and filtering effect in the communication system and other applications.

[0165] The electronic component can be, but is not limited to, a filter, a duplexer, a delay line, a frequency discriminator, or a modulator.

[0166] An electronic device is provided by an embodiment of the present application, which includes a transceiver and a processor. Specifically, the transceiver is configured to receive or send a signal. The transceiver includes the electronic component provided by the present application. The processor is configured to perform signal processing on the signal. The processor is coupled to the transceiver.

[0167] The electronic device includes the electronic component provided by the application, and the electronic component includes the surface acoustic wave resonator provided by the application. The speed adjustment medium is arranged on the electrode finger main area and on the side of the piezoelectric layer facing the substrate, so that the surface acoustic wave propagation speed of the electrode finger main area is greater than the surface acoustic wave propagation speed of the electrode finger edge area, to induce a piston mode in the electrode finger main area, inhibit the propagation of the transverse stray wave, inhibit the transverse stray phenomenon, and further improve the frequency selectivity of the surface acoustic wave resonator, reduce the insertion loss, increase the signal purity, and facilitate signal processing and filtering effect in the communication system and other applications.

[0168] The electronic device can be a terminal device, which can also be referred to as a user equipment (UE), an access terminal, a subscriber unit, a subscriber station, a mobile station, a mobile, a remote station, a remote terminal, a mobile device, a user terminal, a terminal, a wireless communication device, a user agent, or a user device. As examples and not limitation, the terminal device can be a mobile phone, a Pad, a computer with wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, and the like.

[0169] The electronic device 410 can also be a network device, which can be any kind of device with wireless transceiver function, including but not limited to: an evolved node B (eNB), a radio network controller (RNC), a node B (NB), a base station controller (BSC), a base transceiver station (BTS), a home base station (e.g., a home evolved node B or a home node B, HNB), a building base band unit (BBU), an access point (AP) in a wireless fidelity (WIFI) system, a wireless relay node, a wireless backhaul node, a transmission point (TP), a transmission and reception point (TRP), and the like, and can also be a gNB or a TP in a 5G (e.g., a NR) system, one or a group of antenna panels (including multiple antenna panels) of a base station in a 5G system, or a network node constituting a gNB or a TP, such as a BBU or a distributed unit (DU), and the like.

[0170] Referring to FIGS. 22-23e, an embodiment of the present application provides a method for preparing a surface acoustic wave resonator. The surface acoustic wave resonator includes an electrode finger region c and a gap region b. The electrode finger region c includes an electrode finger main region d and electrode finger edge regions e located on both sides of the electrode finger main region d along a first direction m-m. Along the first direction m-m, the electrode finger region c is provided with the gap region b on both sides.

[0171] Specifically, the above preparation method includes:

[0172] S01, providing a substrate initial body.

[0173] S02, forming a first recess corresponding to the electrode finger main region on the upper surface of the substrate initial body, and forming a first speed adjustment medium in the first recess; and / or forming a second speed adjustment medium on the upper surface of the substrate initial body; the substrate has a substrate upper surface provided with the first speed adjustment medium and / or the second speed adjustment medium.

[0174] It can be understood that the way of forming the first recess can be, but is not limited to, etching. The way of forming the first speed adjustment medium and / or the second speed adjustment medium can be, but is not limited to, chemical vapor deposition.

[0175] S03, forming a piezoelectric layer on the upper surface of the substrate; the piezoelectric layer has an upper surface of the piezoelectric layer facing away from the substrate.

[0176] It can be understood that the piezoelectric layer can be formed by chemical vapor deposition, but is not limited thereto.

[0177] It can be understood that the upper surface of the substrate is the surface of the substrate on which the first speed adjustment medium and / or the second speed adjustment medium is arranged.

[0178] S04, forming an interdigital transducer on the upper surface of the piezoelectric layer, the interdigital transducer comprising two interdigital electrodes arranged opposite each other in a first direction; each interdigital electrode comprises a bus bar and a plurality of electrode fingers extending in the first direction; the electrode fingers of the two interdigital electrodes overlap in the first direction in an electrode finger region, and the region between the electrode fingers of one interdigital electrode and the bus bar of the other interdigital electrode is a gap region.

[0179] The first speed adjustment medium is configured to make the surface acoustic wave propagation speed in the main region of the electrode fingers greater than the surface acoustic wave propagation speed in the edge region of the electrode fingers; and the second speed adjustment medium is configured to make the surface acoustic wave propagation speed in the main region of the electrode fingers greater than the surface acoustic wave propagation speed in the edge region of the electrode fingers.

[0180] The surface acoustic wave resonator formed by the above method, the first speed adjustment medium and / or the second speed adjustment medium makes the surface acoustic wave propagation speed in the main region of the electrode fingers greater than the surface acoustic wave propagation speed in the edge region of the electrode fingers, so as to induce a piston mode in the main region of the electrode fingers, and to suppress the propagation of the transverse spurious wave and the transverse spurious phenomenon.

[0181] It can be understood that the surface acoustic wave resonator provided by any of the embodiments of the present application can be formed by the above method.

[0182] Optionally, the method further comprises:

[0183] forming a second groove on the upper surface of the substrate initial body; the second groove is located in the gap region.

[0184] The second speed adjustment medium is at least partially arranged in the second groove.

[0185] Of course, it can be understood that in some feasible embodiments, the substrate can not have a second groove, and accordingly, the step of forming a second groove on the upper surface of the substrate initial body need not be performed.

[0186] In order to more clearly understand the preparation method of the above-mentioned surface acoustic wave resonator, the preparation method of the surface acoustic wave resonator 100 will be described in detail below, which specifically comprises:

[0187] S01, providing a substrate initial body 01, as shown in FIG. 23a.

[0188] Specifically, in this embodiment, the base initial body 01 includes a semiconductor layer 111 and an insulating layer initial layer 113a; wherein the semiconductor layer 111 includes a single crystal silicon layer 1111 and a polycrystalline silicon layer 1113. The insulating layer initial layer 113a is a SiO2 layer. It can be understood that in another feasible embodiment, the structure of the base initial body is not limited to this, and the structure of the base of the surface acoustic wave resonator prepared is adjusted accordingly.

[0189] S02, a first groove 112 corresponding to the electrode finger main area d is formed on the upper surface of the base initial body 01, and a base 110 is obtained, as shown in FIG. 23b; and a first speed regulating medium 141 is formed in the first groove 112, as shown in FIG. 23c. The base 110 has a base upper surface 1131 on which the first groove 112 is arranged.

[0190] S03, a piezoelectric layer 120 is formed on the base upper surface 1131, as shown in FIG. 23d; the piezoelectric layer 120 has a piezoelectric layer upper surface 122 facing away from the base 110.

[0191] S04, an interdigital transducer is formed on the piezoelectric layer upper surface 122, the interdigital transducer includes two interdigital electrodes 131 arranged opposite to each other along a first direction m-m; each interdigital electrode 131 includes a bus bar 132, a plurality of electrode fingers 134 extending along the first direction m-m, and a dummy finger 136; the electrode fingers 134 of the two interdigital electrodes 131 overlap along the first direction m-m in the electrode finger area c, and the area between the electrode fingers 134 of one interdigital electrode 131 and the bus bar 132 of the other interdigital electrode 131 is the gap area b; as shown in FIG. 23e.

[0192] It can be understood that in another feasible embodiment, if there is no dummy finger in the interdigital electrode, the structure of the interdigital electrode formed in the corresponding step S04 can be used.

[0193] Each of the embodiments in the present application focuses on the part different from other embodiments, and each embodiment can be explained by referring to each other. Any combination of the embodiments in the present application is covered by the disclosure of the present application based on the general technical knowledge of the person skilled in the art.

[0194] Each technical feature of the above embodiments can be combined arbitrarily, and in order to make the description simple, not all possible combinations of each technical feature in the above embodiments are described, however, as long as the combination of these technical features does not exist contradictory, it should be considered as the range disclosed in the present application.

[0195] The above is only part of the embodiments in the present application, and does not limit the present application, any modification, equivalent replacement, etc. made within the spirit and principles of the present application should be included in the disclosure range of the present application.

Claims

1. A surface acoustic wave resonator, characterized in that, include: Base; A piezoelectric layer is disposed on the substrate, the piezoelectric layer having an upper surface facing away from the substrate; Interdigitated transducers are located on the upper surface of the piezoelectric layer; The interdigital transducer includes two interdigital electrodes arranged opposite each other along a first direction. Each interdigital electrode includes a busbar and a plurality of electrode fingers extending along the first direction. The area where the electrode fingers of the two interdigital electrodes overlap along the first direction is an electrode finger region. The electrode finger region includes a main electrode finger region and electrode finger edge regions located on both sides of the main electrode finger region along the first direction. The area where the electrode fingers of one interdigital electrode are separated from the busbar of the other interdigital electrode is a gap region. as well as A speed-regulating medium is located on the side of the piezoelectric layer facing the substrate; the speed-regulating medium includes a first speed-regulating medium disposed corresponding to the main region of the electrode finger and / or a second speed-regulating medium located in the gap region, for making the surface acoustic wave propagation speed of the main region of the electrode finger greater than the surface acoustic wave propagation speed of the edge region of the electrode finger.

2. The surface acoustic wave resonator according to claim 1, characterized in that, The substrate has an upper surface facing the piezoelectric layer, and the upper surface of the substrate is provided with a first groove corresponding to the electrode finger region; the first speed regulating medium is disposed in the first groove; the acoustic impedance of the first speed regulating medium is greater than the acoustic impedance of the piezoelectric layer.

3. The surface acoustic wave resonator according to claim 2, characterized in that, The thickness of the first speed regulating medium is in the range of 10nm to 40nm.

4. The surface acoustic wave resonator according to claim 2 or 3, characterized in that, The width of the electrode edge region along the first direction is in the range of 0.2λ to 2.0λ, where λ is the wavelength of the surface acoustic wave resonator.

5. The surface acoustic wave resonator according to any one of claims 2 to 4, characterized in that, The substrate includes a POI substrate; the first groove is disposed on the POI substrate.

6. The surface acoustic wave resonator according to any one of claims 2 to 4, characterized in that, The substrate includes a POI substrate and a Bragg reflector; the Bragg reflector is located between the POI substrate and the piezoelectric layer; the first groove is disposed on the Bragg reflector.

7. The surface acoustic wave resonator according to any one of claims 1 to 6, characterized in that, The density of the second speed-regulating medium is greater than the density of the piezoelectric layer.

8. The surface acoustic wave resonator according to claim 7, characterized in that, The thickness of the second speed regulating medium is in the range of 10nm to 160nm.

9. The surface acoustic wave resonator according to claim 7 or 8, characterized in that, The width of the second speed regulating medium along the first direction is in the range of 0.4λ to 1λ, where λ is the wavelength of the surface acoustic wave resonator.

10. The surface acoustic wave resonator according to claim 7, characterized in that, Each of the gap regions has a plurality of second speed regulating media; the plurality of second speed regulating media are spaced apart along the first direction.

11. The surface acoustic wave resonator according to claim 7 or 10, characterized in that, The substrate has an upper surface facing the piezoelectric layer, and the upper surface of the substrate is provided with a second groove, wherein the second speed regulating medium is at least partially disposed in the second groove.

12. The surface acoustic wave resonator according to claim 7 or 10, characterized in that, The piezoelectric layer has a lower surface facing the substrate, and the lower surface of the piezoelectric layer is provided with a third groove, wherein the second speed regulating medium is at least partially disposed in the third groove.

13. The surface acoustic wave resonator according to claim 11, characterized in that, The substrate includes a POI substrate; the second groove is disposed on the POI substrate.

14. The surface acoustic wave resonator according to claim 11, characterized in that, The substrate includes a POI substrate and a Bragg reflector; the Bragg reflector is located between the POI substrate and the piezoelectric layer; the second groove is disposed on the Bragg reflector.

15. A surface acoustic wave resonator substrate, characterized in that, The surface acoustic wave resonator substrate includes an electrode finger region and a gap region; the electrode finger region includes a main electrode finger region and electrode finger edge regions located on both sides of the main electrode finger region along a first direction; Along the first direction, the gap region is provided on both sides of the electrode finger region; The surface acoustic wave resonator substrate includes: The substrate has an upper surface; as well as A speed-regulating medium is located on the upper surface of the substrate. The speed-regulating medium includes a first speed-regulating medium disposed corresponding to the main region of the electrode finger and / or a second speed-regulating medium disposed in the gap region, for making the surface acoustic wave propagation speed of the main region of the electrode finger greater than the surface acoustic wave propagation speed of the edge region of the electrode finger.

16. The surface acoustic wave resonator substrate according to claim 15, characterized in that, The upper surface of the substrate is provided with a first groove corresponding to the main area of ​​the electrode finger; the first speed regulating medium is disposed in the first groove.

17. The surface acoustic wave resonator substrate according to claim 16, characterized in that, The substrate includes a POI substrate; the first groove is disposed on the POI substrate.

18. The surface acoustic wave resonator substrate according to claim 16, characterized in that, The substrate includes a POI substrate and a Bragg reflector; the first groove is disposed on the Bragg reflector and is located on the surface of the Bragg reflector opposite to the POI substrate.

19. The surface acoustic wave resonator substrate according to any one of claims 15 to 18, characterized in that, The upper surface of the substrate is provided with a second groove, and the second speed regulating medium is at least partially disposed in the second groove.

20. The surface acoustic wave resonator substrate according to claim 19, characterized in that, The substrate includes a POI substrate; the second groove is disposed on the POI substrate.

21. The surface acoustic wave resonator substrate according to claim 19, characterized in that, The substrate includes a POI substrate and a Bragg reflector; the second groove is disposed on the Bragg reflector and is located on the surface of the Bragg reflector opposite to the POI substrate.

22. An electronic component, characterized in that, Includes one or more surface acoustic wave resonators as described in any one of claims 1 to 14.

23. An electronic device, characterized in that, include: A transceiver for receiving or transmitting signals, the transceiver comprising the electronic components as described in claim 22; A processor for processing the signal, wherein the processor is coupled to the transceiver.

24. A method for fabricating a surface acoustic wave resonator, characterized in that, The surface acoustic wave resonator includes an electrode finger region and a gap region; the electrode finger region includes a main electrode finger region and electrode finger edge regions located on both sides of the main electrode finger region along a first direction; Along the first direction, the gap region is provided on both sides of the electrode finger region; The preparation method includes: Provide the base prototype; A first groove corresponding to the electrode finger region is formed on the upper surface of the substrate, and a first speed regulating medium is formed in the first groove; and / or, a second speed regulating medium is formed on the upper surface of the substrate; the substrate has an upper surface on which the first speed regulating medium and / or the second speed regulating medium are disposed; A piezoelectric layer is formed on the upper surface of the substrate; the piezoelectric layer has an upper surface facing away from the substrate; and An interdigital transducer is formed on the upper surface of the piezoelectric layer. The interdigital transducer includes two interdigital electrodes disposed opposite to each other along the first direction. Each interdigital electrode includes a busbar and a plurality of electrode fingers extending along the first direction. The electrode fingers of the two interdigital electrodes overlap in the electrode finger region along the first direction. The region between the electrode finger of one interdigital electrode and the busbar of the other interdigital electrode is a gap region. Wherein, the first speed-regulating medium is used to make the surface acoustic wave propagation speed of the main region of the electrode finger greater than the surface acoustic wave propagation speed of the edge region of the electrode finger; the second speed-regulating medium is used to make the surface acoustic wave propagation speed of the main region of the electrode finger greater than the surface acoustic wave propagation speed of the edge region of the electrode finger.

25. The preparation method according to claim 24, characterized in that, Also includes: A second groove is formed on the upper surface of the substrate; the second groove is located in the gap region. in The second speed regulating medium is at least partially disposed within the second groove.

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