Surface acoustic wave resonance device, forming method thereof and surface acoustic wave filtering device
By introducing a failure component into the surface acoustic wave resonator, the electromechanical coupling effect outside the resonant region is reduced, the high-order nonlinearity problem of the RF filter is solved, and the passband performance of the filter is improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHANGZHOU CHEMSEMI CO LTD
- Filing Date
- 2025-12-31
- Publication Date
- 2026-04-17
AI Technical Summary
The high-order nonlinearity of RF filters leads to mutual interference between different frequency bands, significantly reducing the passband performance of filters and affecting the use of integrated devices such as duplexers, multiplexers, and RF front-end modules.
By introducing a failure region into the surface acoustic wave resonator, the electromechanical coupling effect outside the resonant region is reduced. The failure region is filled with particle injection or non-piezoelectric materials to suppress high-order nonlinearity.
Without affecting insertion loss, power tolerance, and chip size, it effectively suppresses high-order nonlinearities, such as third-order nonlinearities, thereby improving filter performance.
Smart Images
Figure CN121887147A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of semiconductor technology, and in particular to a surface acoustic wave (SAW) resonator and its formation method, as well as a SAW filter. Background Technology
[0002] Radio frequency (RF) front-end chips in wireless communication devices include devices such as RF power amplifiers, RF switches, RF filters, RF multiplexers (e.g., duplexers, quadplexers, etc.), and low-noise amplifiers. Among these, RF filters include surface-acoustic wave (SAW) filters, bulk-acoustic wave (BAW) filters, microelectromechanical system (MEMS) filters, and integrated passive device (IPD) filters.
[0003] For integrated devices such as duplexers, multiplexers, and RF front-end modules, the high-order nonlinearity of RF filters can cause mutual interference between different frequency bands, significantly reducing the passband performance of the filters. Therefore, solving the high-order nonlinearity problem of filters has become one of the important topics in the research and development of RF filter technology. Summary of the Invention
[0004] This invention provides a surface acoustic wave (SAW) resonator and its formation method, as well as a SAW filter, which can suppress high-order nonlinearity.
[0005] This invention provides a surface acoustic wave resonator, comprising: Substrate, the substrate including a piezoelectric layer; An interdigitated electrode is located on the piezoelectric layer, and the interdigitated electrode sequentially includes a first bus, a first gap, an overlapping portion, a second gap, and a second bus along a first direction; The piezoelectric layer comprises, along the first direction, a first part, a first failed part, an effective part, a second failed part, and a second part in sequence; wherein, the electromechanical coupling effect of the effective part is effective; Wherein, the first bus is located on the first part, the first gap is located on the first failed part, the overlapping part is located on the effective part, the second gap is located on the second failed part, and the second bus is located on the second part.
[0006] Optionally, the interdigitated electrode further includes: a first spurious finger portion and a second spurious finger portion, wherein the first spurious finger portion is located between the first bus and the first gap portion along the first direction, and the second spurious finger portion is located between the second gap portion and the second bus along the first direction.
[0007] Furthermore, the first dummy finger portion is also located on the first portion, and the second dummy finger portion is also located on the second portion; wherein, the electromechanical coupling effect of the first portion is effective, and the electromechanical coupling effect of the second portion is effective.
[0008] Furthermore, the first dummy finger portion is also located on the first failed portion, and the second dummy finger portion is also located on the second failed portion.
[0009] Optionally, it further includes: a first reflective grating and a second reflective grating, wherein the first reflective grating, the overlapping portion and the second reflective grating are placed sequentially along a second direction, the second direction being perpendicular to the first direction; the first reflective grating and the second reflective grating are located on the effective portion.
[0010] Furthermore, the first reflective grating, the first gap portion, and the second reflective grating are arranged sequentially along the second direction; the first reflective grating is also located on the first failure portion and the second failure portion, and the second reflective grating is also located on the first failure portion and the second failure portion.
[0011] Optionally, the substrate further includes: a base and an intermediate layer located on the base, the intermediate layer being located between the base and the piezoelectric layer.
[0012] Optionally, the first failure part and the second failure part include particles.
[0013] Optionally, the first failure portion and the second failure portion comprise non-piezoelectric materials.
[0014] This invention provides a surface acoustic wave (SAW) filtering device, comprising: a SAW resonator as described in any of the above embodiments.
[0015] This invention provides a method for forming a surface acoustic wave resonator, comprising: Forming a substrate, including forming a piezoelectric layer; An interdigitated electrode is formed on the piezoelectric layer, and the interdigitated electrode sequentially includes a first bus, a first gap, an overlapping portion, a second gap, and a second bus along a first direction. The piezoelectric layer includes, in sequence along the first direction, a first part, a first failed part, an effective part, a second failed part, and a second part, wherein the electromechanical coupling effect of the effective part is effective; Wherein, the first bus is located on the first part, the first gap is located on the first failed part, the overlapping part is located on the effective part, the second gap is located on the second failed part, and the second bus is located on the second part.
[0016] Optionally, the interdigitated electrode further includes: a first pseudo-finger portion and a second pseudo-finger portion, wherein the first pseudo-finger portion is located between the first bus and the first gap portion along the first direction, and the second pseudo-finger portion is located between the second gap portion and the second bus along the first direction.
[0017] Furthermore, the first dummy finger portion is also located on the first portion, and the second dummy finger portion is also located on the second portion; wherein, the electromechanical coupling effect of the first portion is effective, and the electromechanical coupling effect of the second portion is effective.
[0018] Furthermore, the first dummy finger portion is also located on the first failed portion, and the second dummy finger portion is also located on the second failed portion.
[0019] Optionally, forming the substrate includes: implanting particles into a predetermined area on the surface of the piezoelectric layer to form the first failure portion and the second failure portion.
[0020] Optionally, forming the substrate includes: slotting a predetermined area on the surface of the piezoelectric layer to form a first groove and a second groove; forming a non-piezoelectric material in the first groove and the second groove to form the first failure portion and the second failure portion.
[0021] The beneficial effects of this invention are: it effectively suppresses high-order nonlinearities, such as third-order nonlinearities, caused by electromechanical coupling outside the resonant region without significantly affecting insertion loss, power tolerance, and chip size. Furthermore, extending the failure region to the bus can also effectively suppress gap modes. Attached Figure Description
[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0023] Figure 1 This is a top view of an interdigitated electrode structure. Figure 2 This is a top view of another type of interdigitated electrode structure; Figure 3 This is a top view schematic diagram of a surface acoustic wave resonator provided in an embodiment of the present invention; Figure 4This is a top view schematic diagram of a surface acoustic wave resonator provided in another embodiment of the present invention; Figure 5 This is a top view schematic diagram of a surface acoustic wave resonator provided in another embodiment of the present invention; Figure 6 This is a top view schematic diagram of a surface acoustic wave resonator provided in another embodiment of the present invention; Figure 7 This is a top view schematic diagram of a surface acoustic wave resonator provided in another embodiment of the present invention; Figure 8 This is a schematic diagram of the cross-sectional structure of a surface acoustic wave resonator provided in an embodiment of the present invention; Figure 9 This is a schematic diagram of the cross-sectional structure of a surface acoustic wave resonator provided in another embodiment of the present invention; Figure 10 This is a schematic flowchart of a method for forming a surface acoustic wave resonator according to an embodiment of the present invention. Detailed Implementation
[0024] Any feature disclosed in this specification (including any appended claims, abstract, and drawings) may be replaced by other equivalent or similar features, unless specifically stated otherwise. That is, unless specifically stated otherwise, each feature is merely one example of a series of equivalent or similar features.
[0025] All features disclosed in this specification, or all steps in all disclosed methods or processes, may be combined in any way, except for mutually exclusive features and / or steps.
[0026] The high-order nonlinearity (such as second-order and third-order nonlinearity) of radio frequency filters (such as surface acoustic wave filters and bulk acoustic wave filters) is prominent. It can cause mutual interference between different frequency bands, significantly reduce the passband performance of the filter, and affect the use of integrated devices such as duplexers, multiplexers and radio frequency front-end modules.
[0027] Research indicates that the primary cause of second-order nonlinearity is the asymmetry of the filter. Therefore, for surface acoustic wave (SAW) filters, splitting an interdigital transducer into two axisymmetric, parallel interdigital transducers can effectively suppress second-order nonlinearity, but this requires more space. Furthermore, the suppression effect on third-order nonlinearity is not significant. Other studies have shown that one cause of higher-order nonlinearity is the electromechanical coupling effect generated outside the resonant region. Therefore, reducing the electromechanical coupling effect outside the resonant region can effectively suppress higher-order nonlinearity (e.g., third-order nonlinearity).
[0028] Figure 1 This is a top view of the structure of an interdigitated electrode.
[0029] See Figure 1 A surface acoustic wave resonator includes a piezoelectric layer 1 and an interdigital transducer located on the piezoelectric layer 1. The interdigital transducer includes: a first bus 2a and a second bus 2b placed parallel to a first direction X; a plurality of first interdigits 3a and a plurality of second interdigits 3b placed parallel to a second direction Y, wherein the first direction X is perpendicular to the second direction Y, the plurality of first interdigits 3a are connected to the first bus 2a, and the plurality of second interdigits 3b are connected to the second bus 2b. The plurality of first interdigits 3a and the plurality of second interdigits 3b are alternately arranged between the first bus 2a and the second bus 2b and have an overlapping area (within the dashed box); and a first gap 4a located between the ends of the first bus 2a and the second interdigits 3b and a second gap 4b located between the ends of the second bus 2b and the first interdigits 3a.
[0030] Figure 2 This is a top view of another type of interdigitated electrode structure.
[0031] See Figure 2 Another surface acoustic wave resonator includes a piezoelectric layer 1 and an interdigital transducer located on the piezoelectric layer 1. The interdigital transducer includes: a first bus 2a and a second bus 2b placed parallel to a first direction X; a plurality of first interdigits 3a and a plurality of second interdigits 3b placed parallel to a second direction Y, wherein the first direction X is perpendicular to the second direction Y, the plurality of first interdigits 3a are connected to the first bus 2a, and the plurality of second interdigits 3b are connected to the second bus 2b. The plurality of first interdigits 3a and the plurality of second interdigits 3b are alternately arranged between the first bus 2a and the second bus 2b and have an overlapping area (within the dashed box); a plurality of first pseudo-fingers 5a and a plurality of second pseudo-fingers 5b, wherein the plurality of first pseudo-fingers 5a and the plurality of second pseudo-fingers 5b are arranged parallel to the first bus 2a and the second bus 2b. A first bus 2a is connected, and a plurality of second prosthetic fingers 5b are connected to the second bus 2b. Along the first direction X, the plurality of first prosthetic fingers 5a are respectively aligned with a plurality of second interdigitates 3b, and the plurality of second prosthetic fingers 5b are respectively aligned with a plurality of first interdigitates 3a. A first gap 4a is located between the end of the first prosthetic finger 5a and the end of the second interdigitate 3b, and a second gap 4b is located between the end of the second prosthetic finger 5b and the end of the first interdigitate 3a. A reflective grating 6 is located on both sides of the plurality of alternately arranged first interdigitates 3a and the plurality of second interdigitates 3b along the second direction Y. The reflective grating 6 is located between the first bus 2a and the second bus 2b, and is connected to the first bus 2a and the second bus 2b respectively.
[0032] It should be noted that by applying electrical signals of opposite polarity to the first interdigitate finger 3a and the second interdigitate finger 3b respectively, an alternating electric field is formed in the overlapping region, which excites the electromechanical coupling effect of the piezoelectric layer 1 to convert the electrical signal into a surface acoustic wave. Furthermore, the first pseudo-finger 5a and the second pseudo-finger 5b are used to suppress the radiation of the surface acoustic wave towards the two bus directions. In addition, the reflective grating 6 is used to reflect the generated surface acoustic wave and suppress acoustic leakage.
[0033] Figure 3 This is a top view schematic diagram of a surface acoustic wave resonator provided in an embodiment of the present invention.
[0034] See Figure 3 This invention provides a surface acoustic wave resonator, comprising: Substrate, the substrate including a piezoelectric layer 1; Interdigitated electrode 2, located on the piezoelectric layer 1, includes, along the first direction X, a first bus 201, a first gap 203, an overlapping portion 205, a second gap 207, and a second bus 209. The overlapping portion 205 corresponds to the part in the interdigitated transducer where multiple first interdigitates and multiple second interdigitates intersect and overlap. The first gap 203 corresponds to the part in the interdigitated transducer where the first gap is located, and the second gap 207 corresponds to the part in the interdigitated transducer where the second gap is located. The piezoelectric layer 1 includes, along the first direction X, a first part 101, a first failure part 103, an effective part 105, a second failure part 107, and a second part 109 in sequence; wherein the electromechanical coupling effect of the effective part 105 is effective, and the electromechanical coupling effect of the first failure part 103 and the second failure part 107 is ineffective. Wherein, the first bus 201 is located on the first part 101, the second bus 209 is located on the second part 109, the first gap part 203 is located on the first failure part 103, the second gap part 207 is located on the second failure part 107, and the overlapping part 205 is located on the effective part 105.
[0035] It should be noted that the first gap 203 is located on the first failure part 103, and the second gap 207 is located on the second failure part 107. The parasitic electric fields of the first gap 203 and the second gap 207 will not excite the electromechanical coupling effect of the piezoelectric layer 1, thereby effectively suppressing the high-order nonlinearity caused by electromechanical coupling outside the resonant region, such as the third nonlinearity.
[0036] In this embodiment, the material of the piezoelectric layer 1 includes lithium tantalate. In another embodiment, the material of the piezoelectric layer 1 includes one of the following: lithium niobate, quartz, and aluminum nitride.
[0037] See Figure 8 In this embodiment, the substrate is a single-layer structure, consisting only of the piezoelectric layer 1.
[0038] In this embodiment, the first failure section 103 and the second failure section 107 include injected particles, wherein the particles include charged particles, and the charged particles include at least one of the following: helium ions, argon ions, phosphorus ions, and boron ions. It should be noted that when charged particles such as helium ions and argon ions are injected with high energy into the predetermined region of the piezoelectric layer 1, the particles will collide violently with the atoms in the crystal lattice, resulting in atomic displacement, vacancies, or dislocations and other lattice defects. These defects will disrupt the orderly arrangement of atoms, hinder the directional migration of charges and the cooperative deformation of atoms, making the region unable to effectively respond to electrical signals to generate effective surface acoustic waves, and unable to effectively convert acoustic energy into electrical energy. Ultimately, the electromechanical coupling effect is greatly weakened or even failed, thereby reducing the high-order nonlinearity caused by parasitic electromechanical coupling outside the resonant region.
[0039] Figure 4 and Figure 5 This is a top view schematic diagram of a surface acoustic wave resonator provided in another embodiment of the present invention.
[0040] See Figure 4 and Figure 5 This embodiment provides a surface acoustic wave resonator, comprising: Substrate, the substrate including a piezoelectric layer 1; Interdigitated electrode 2 is located on the piezoelectric layer 1. The interdigitated electrode 2 includes, in sequence along the first direction X, a first bus 201, a first gap 203, an overlapping portion 205, a second gap 207, and a second bus 209. The piezoelectric layer 1 includes, along the first direction X, a first part 101, a first failure part 103, an effective part 105, a second failure part 107, and a second part 109 in sequence; wherein the electromechanical coupling effect of the effective part 105 is effective, and the electromechanical coupling effect of the first failure part 103 and the second failure part 107 is ineffective. Wherein, the first bus 201 is located on the first part 101, the second bus 209 is located on the second part 109, the first gap part 203 is located on the first failure part 103, the second gap part 207 is located on the second failure part 107, and the overlapping part 205 is located on the effective part 105.
[0041] It should be noted that the first gap 203 is located on the first failure part 103, and the second gap 207 is located on the second failure part 107. The parasitic electric fields of the first gap 203 and the second gap 207 will not excite the electromechanical coupling effect of the piezoelectric layer 1, thereby effectively suppressing the high-order nonlinearity caused by electromechanical coupling outside the resonant region, such as the third nonlinearity.
[0042] In this embodiment, the interdigital electrode 2 further includes: a first pseudo-finger portion 202 and a second pseudo-finger portion 208. The first pseudo-finger portion 202 is located between the first bus 201 and the first gap portion 203 along the first direction X. The second pseudo-finger portion 208 is located between the second gap portion 207 and the second bus 209 along the first direction X. The first pseudo-finger portion 202 corresponds to the part of the interdigital transducer where the first pseudo-finger is located, and the second pseudo-finger portion 208 corresponds to the part of the interdigital transducer where the second pseudo-finger is located. In this embodiment, the first pseudo-finger portion 202 is also located on the first portion 101, and the second pseudo-finger portion 208 is also located on the second portion 109; wherein, the electromechanical coupling effect of the first portion 101 is effective, and the electromechanical coupling effect of the second portion 109 is effective.
[0043] In this embodiment, the interdigitated electrode 2 further includes: a first reflective grid 204 and a second reflective grid 206. The first reflective grid 204, the overlapping portion 205 and the second reflective grid 206 are placed sequentially along a second direction Y, which is perpendicular to the first direction X. The first reflective grid 204 and the second reflective grid 206 are located on the effective portion 105.
[0044] In this embodiment, the first reflective grating 204, the first gap portion 203, and the second reflective grating 206 are placed sequentially along the second direction Y, and the first reflective grating 204, the second gap portion 207, and the second reflective grating 206 are placed sequentially along the second direction Y; the first reflective grating 204 is also located on the first failure portion 103 and the second failure portion 107, and the second reflective grating 206 is also located on the first failure portion 103 and the second failure portion 107.
[0045] In this embodiment, the material of the piezoelectric layer 1 includes lithium tantalate. In another embodiment, the material of the piezoelectric layer 1 includes one of the following: lithium niobate, quartz, and aluminum nitride.
[0046] See Figure 9 In this embodiment, the substrate further includes: a substrate 3 (such as a sapphire, silicon, or silicon carbide substrate) and an intermediate layer 4 (such as silicon dioxide or aluminum nitride) located on the substrate, wherein the intermediate layer is located between the substrate 3 and the piezoelectric layer 1.
[0047] In this embodiment, the first failure portion 103 and the second failure portion 107 comprise non-piezoelectric materials. It should be noted that the first void portion 203 and the second void portion 207 are located on the piezoelectric material.
[0048] Figure 6 and Figure 7 This is a top view schematic diagram of a surface acoustic wave resonator provided in another embodiment of the present invention.
[0049] See Figure 6 and Figure 7 This embodiment provides a surface acoustic wave resonator, comprising: Substrate, the substrate including a piezoelectric layer 1; Interdigitated electrode 2 is located on the piezoelectric layer 1. The interdigitated electrode 2 includes, in sequence along the first direction X, a first bus 201, a first gap 203, an overlapping portion 205, a second gap 207, and a second bus 209. The piezoelectric layer 1 includes, along the first direction X, a first part 101, a first failure part 103, an effective part 105, a second failure part 107, and a second part 109 in sequence; wherein the electromechanical coupling effect of the effective part 105 is effective, and the electromechanical coupling effect of the first failure part 103 and the second failure part 107 is ineffective. Wherein, the first bus 201 is located on the first part 101, the first gap part 203 is located on the first failure part 103, the overlapping part 205 is located on the effective part 105, the second gap part 207 is located on the second failure part 107, and the second bus 209 is located on the second part 109.
[0050] It should be noted that the first gap 203 is located on the first failure part 103, and the second gap 207 is located on the second failure part 107. The parasitic electric fields of the first gap 203 and the second gap 207 will not excite the electromechanical coupling effect of the piezoelectric layer 1, thereby effectively suppressing the high-order nonlinearity caused by electromechanical coupling outside the resonant region, such as the third nonlinearity.
[0051] In this embodiment, the interdigital electrode 2 further includes: a first pseudo-finger portion 202 and a second pseudo-finger portion 208. The first pseudo-finger portion 202 is located between the first bus 201 and the first gap portion 203 along the first direction X, and the second pseudo-finger portion 208 is located between the second gap portion 207 and the second bus 209 along the first direction X.
[0052] In this embodiment, the first pseudo-finger portion 202 is also located on the first failure portion 103, and the second pseudo-finger portion 208 is also located on the second failure portion 107. It should be noted that the first pseudo-finger portion 202 and the second pseudo-finger portion 208 introduce parasitic electric fields, excite electromechanical coupling effects, and in particular, excite the generation of gap modes. Therefore, the fact that the first pseudo-finger portion 202 is also located on the first failure portion 103 and the second pseudo-finger portion 208 is also located on the second failure portion 107 can further suppress high-order nonlinearity and also suppress gap modes.
[0053] In this embodiment, the interdigitated electrode 2 further includes: a first reflective grid 204 and a second reflective grid 206. The first reflective grid 204, the overlapping portion 205 and the second reflective grid 206 are placed sequentially along a second direction Y, which is perpendicular to the first direction X. The first reflective grid 204 and the second reflective grid 206 are located on the effective portion 105.
[0054] In this embodiment, the first reflective grating 204, the first gap portion 203, and the second reflective grating 206 are placed sequentially along the second direction Y, and the first reflective grating 204, the second gap portion 207, and the second reflective grating 206 are placed sequentially along the second direction Y; the first reflective grating 204 is also located on the first failure portion 103 and the second failure portion 107, and the second reflective grating 206 is also located on the first failure portion 103 and the second failure portion 107.
[0055] See Figure 9 In this embodiment, the substrate further includes: a substrate 3 (such as a sapphire, silicon, or silicon carbide substrate) and an intermediate layer 4 (such as silicon dioxide or aluminum nitride) located on the substrate, wherein the intermediate layer is located between the substrate 3 and the piezoelectric layer 1.
[0056] In this embodiment, the first failure section 103 and the second failure section 107 include injected particles, wherein the particles include charged particles, and the charged particles include at least one of the following: helium ions, argon ions, phosphorus ions, and boron ions.
[0057] This invention also provides a surface acoustic wave (SAW) filtering device, comprising: a SAW resonator as described in any of the above embodiments.
[0058] Figure 10 This is a schematic flowchart of a method for forming a surface acoustic wave resonator according to an embodiment of the present invention.
[0059] See Figure 10 This embodiment provides a method for forming a surface acoustic wave resonator, including: Step 1.1, forming a substrate, including forming a piezoelectric layer; The piezoelectric layer includes, along the first direction X, a first part, a first failed part, an effective part, a second failed part, and a second part in sequence, and the electromechanical coupling effect of the effective part is effective; Step 1.2: Form interdigitated electrodes on the piezoelectric layer; The interdigitated electrode includes, along the first direction X, a first bus, a first gap, an overlapping portion 205, a second gap, and a second bus. The first bus is located on the first portion, the first gap is located on the first failure portion, the overlapping portion 205 is located on the effective portion, the second gap is located on the second failure portion, and the second bus is located on the second portion.
[0060] It should be noted that the first void is located on the first failure part, and the second void is located on the second failure part. The parasitic electric fields of the first void and the second void will not excite the electromechanical coupling effect of the piezoelectric layer, thereby effectively suppressing the high-order nonlinearity, such as the third nonlinearity, caused by electromechanical coupling outside the resonant region.
[0061] In this embodiment, the interdigitated electrode further includes: a first pseudo-finger portion and a second pseudo-finger portion, wherein the first pseudo-finger portion is located between the first bus and the first gap portion along the first direction X, and the second pseudo-finger portion is located between the second gap portion and the second bus along the first direction X.
[0062] In this embodiment, the first dummy finger portion is also located on the first portion, and the second dummy finger portion is also located on the second portion; wherein, the electromechanical coupling effect of the first portion is effective, and the electromechanical coupling effect of the second portion is effective.
[0063] In another embodiment, the first pseudo-finger portion is also located on the first failure portion, and the second pseudo-finger portion is also located on the second failure portion. It should be noted that the first and second pseudo-finger portions introduce parasitic electric fields, exciting electromechanical coupling effects, and in particular, exciting the generation of gap modes. Therefore, the fact that the first and second pseudo-finger portions are located on the first and second failure portions can further suppress higher-order nonlinearities and also suppress gap modes.
[0064] In this embodiment, step 1.1 includes: step 1.11, providing a substrate; forming an intermediate layer on the substrate; bonding the intermediate layer to the piezoelectric layer, wherein the intermediate layer is located between the substrate and the piezoelectric layer. In this embodiment, a bonding process is used to bond the intermediate layer and the piezoelectric layer. In another embodiment, an adhesive method can be used to bond the substrate and the piezoelectric layer.
[0065] In this embodiment, step 1.1 further includes: step 1.12, performing high-energy particle implantation on a predetermined area of the piezoelectric layer surface to form the first failure portion and the second failure portion. It should be noted that high-energy particle implantation will destroy the piezoelectric crystal lattice structure of the predetermined area, significantly reducing or even eliminating piezoelectricity, thus forming the first failure portion and the second failure portion with electromechanical coupling failure.
[0066] In another embodiment, forming the substrate includes: etching a predetermined area on the surface of the piezoelectric layer to form a first groove and a second groove; filling the first groove and the second groove with a non-piezoelectric material to form the first failure portion and the second failure portion. It should be noted that chemical vapor deposition (CVD) or physical vapor deposition (PVD) processes can be used to fill the first groove and the second groove with a non-piezoelectric material (such as silicon dioxide, silicon nitride, or polymer), and after planarization, the first failure portion and the second failure portion are formed flush with the surface of the piezoelectric layer.
[0067] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.
Claims
1. A surface acoustic wave resonator device, characterized by, include: Substrate, the substrate including a piezoelectric layer; An interdigitated electrode is located on the piezoelectric layer, and the interdigitated electrode sequentially includes a first bus, a first gap, an overlapping portion, a second gap, and a second bus along a first direction; The piezoelectric layer comprises, along the first direction, a first part, a first failed part, an effective part, a second failed part, and a second part in sequence; wherein, the electromechanical coupling effect of the effective part is effective; Wherein, the first bus is located on the first part, the first gap is located on the first failed part, the overlapping part is located on the effective part, the second gap is located on the second failed part, and the second bus is located on the second part.
2. The surface acoustic wave resonator as described in claim 1, characterized in that, The interdigitated electrode further includes: a first pseudo-finger portion and a second pseudo-finger portion, wherein the first pseudo-finger portion is located between the first bus and the first gap portion along the first direction, and the second pseudo-finger portion is located between the second gap portion and the second bus along the first direction.
3. The surface acoustic wave resonator as described in claim 2, characterized in that, The first pseudo-finger portion is also located on the first part, and the second pseudo-finger portion is also located on the second part; wherein, the electromechanical coupling effect of the first part is effective, and the electromechanical coupling effect of the second part is effective.
4. The surface acoustic wave resonator as described in claim 2, characterized in that, The first dummy finger is also located on the first failed part, and the second dummy finger is also located on the second failed part.
5. The surface acoustic wave resonator as described in claim 1, characterized in that, Also includes: A first reflective grating and a second reflective grating are arranged sequentially along a second direction, which is perpendicular to the first direction; the first reflective grating and the second reflective grating are located on the effective portion.
6. The surface acoustic wave resonator as described in claim 5, characterized in that, The first reflective grating, the first gap portion, and the second reflective grating are placed sequentially along the second direction; the first reflective grating is also located on the first failure portion and the second failure portion, and the second reflective grating is also located on the first failure portion and the second failure portion.
7. The surface acoustic wave resonator as described in claim 1, characterized in that, The substrate further includes: a base and an intermediate layer located on the base, the intermediate layer being located between the base and the piezoelectric layer.
8. The surface acoustic wave resonator as described in claim 1, characterized in that, The first failure part and the second failure part include particles.
9. The surface acoustic wave resonator as described in claim 1, characterized in that, The first failure portion and the second failure portion comprise non-piezoelectric materials.
10. A surface acoustic wave (SAW) filtering device, characterized in that, include: The surface acoustic wave resonator as described in any one of claims 1 to 9.
11. A method for forming a surface acoustic wave resonator, characterized in that, include: Forming a substrate, including forming a piezoelectric layer; An interdigitated electrode is formed on the piezoelectric layer, and the interdigitated electrode sequentially includes a first bus, a first gap, an overlapping portion, a second gap, and a second bus along a first direction. The piezoelectric layer comprises, along the first direction, a first part, a first failed part, an effective part, a second failed part, and a second part, wherein the electromechanical coupling effect of the effective part is effective; Wherein, the first bus is located on the first part, the first gap is located on the first failed part, the overlapping part is located on the effective part, the second gap is located on the second failed part, and the second bus is located on the second part.
12. The method as described in claim 11, characterized in that, The interdigitated electrode further includes: a first pseudo-finger portion and a second pseudo-finger portion, wherein the first pseudo-finger portion is located between the first bus and the first gap portion along the first direction, and the second pseudo-finger portion is located between the second gap portion and the second bus along the first direction.
13. The method as described in claim 12, characterized in that, The first pseudo-finger portion is also located on the first part, and the second pseudo-finger portion is also located on the second part; wherein, the electromechanical coupling effect of the first part is effective, and the electromechanical coupling effect of the second part is effective.
14. The method as described in claim 12, characterized in that, The first dummy finger is also located on the first failed part, and the second dummy finger is also located on the second failed part.
15. The method as described in claim 11, characterized in that, The substrate formation includes: performing particle implantation on a predetermined area of the piezoelectric layer surface to form the first failure portion and the second failure portion.
16. The method as described in claim 11, characterized in that, The substrate formation includes: slotting a predetermined area on the surface of the piezoelectric layer to form a first groove and a second groove; forming a non-piezoelectric material in the first groove and the second groove to form the first failure portion and the second failure portion.