Surface acoustic wave resonance device and forming method thereof

Abstract

The invention discloses a surface acoustic wave resonance device and a forming method thereof, and the device comprises a piezoelectric substrate which comprises a first side and a second side, and comprises a first device region, an isolation region and a second device region; a first electrode structure on the first side of the first device region; a second electrode structure on the first side of the second device region; the piezoelectric substrate comprises a first part, the first part is located in the isolation region, and doped particles are arranged in the first part. Leaky waves excited by the first electrode structures or the second electrode structures on the adjacent device regions and reflector waves reflected by the leaky waves in the piezoelectric substrate are scattered after passing through the isolation regions and making contact with the first parts, so that the intensity of the reflector waves transmitted to the adjacent device regions can be inhibited; therefore, interference caused by the fact that reflected body waves enter adjacent device areas can be reduced, clutters introduced into a filter passband are reduced, and the performance of the surface acoustic wave resonance device is improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a surface acoustic wave resonance device and a method for forming the same. Background Art

[0002] The RF front-end chips of wireless communication devices include power amplifiers, antenna switches, RF filters, multiplexers, and low-noise amplifiers, etc. Among them, RF filters include piezoelectric surface acoustic wave (SAW) filters, piezoelectric bulk acoustic wave (BAW) filters, micro-electro-mechanical system (MEMS) filters, integrated passive devices (IPD) filters, etc.

[0003] The quality factor (Q value) of the SAW resonator is relatively high. The RF filter made of SAW resonator has low insertion loss and high out-band rejection, that is, SAW filter, which is the mainstream RF filter used in wireless communication devices such as mobile phones and base stations.

[0004] However, there are still many problems with surface acoustic wave resonator devices. Summary of the invention

[0005] The problem solved by the present invention is to provide a surface acoustic wave resonance device and a method for forming the same, so as to improve the performance of the surface acoustic wave resonance device.

[0006] To solve the above problems, the technical solution of the present invention provides a surface acoustic wave resonance device, including: a piezoelectric substrate, the piezoelectric substrate having a first side and a second side opposite to each other, the piezoelectric substrate including a first device region, a second device region and an isolation region arranged along a first direction, the isolation region being located between the first device region and the second device region; a first electrode structure located on the first device region, the first electrode structure being located on the first side; a second electrode structure located on the second device region, the second electrode structure being located on the first side; the piezoelectric substrate including a first portion, the first portion being located in the isolation region, and the first portion having doped particles therein.

[0007] Optionally, the first part includes: a plurality of layers of sub-parts, each layer of the sub-parts contains doped particles, and the doped particles in adjacent sub-parts are different.

[0008] Optionally, the doping particles in adjacent sub-divisions are different includes: the particle radii of the doping particles in adjacent sub-divisions are different.

[0009] Optionally, the piezoelectric substrate further includes a second portion, the second portion is located in the first device region, the second device region and the isolation region, and the first portion is located between the second portion and the first side surface of the piezoelectric substrate.

[0010] Optionally, the second part contains doped particles.

[0011] Optionally, the doping particles in the second portion are different from the doping particles in the first portion.

[0012] Optionally, the doping particles in the second portion are the same as at least part of the doping particles in the first portion.

[0013] Optionally, doping particles in a portion of the first portion adjacent to the second portion are the same as doping particles in the second portion.

[0014] Optionally, the doped particles include hydrogen ions or helium ions.

[0015] Optionally, the second portion is located on a second side surface of the piezoelectric substrate.

[0016] Optionally, the second portion includes an irregular concave-convex structure.

[0017] Optionally, a distance between the first portion and the second side surface of the piezoelectric substrate is 10 microns to 100 microns.

[0018] Optionally, the first electrode structure and the second electrode structure both include: a first bus and a second bus extending along the first direction and arranged in parallel along the second direction, the first direction being perpendicular to the second direction; a plurality of first electrode strips connected to the first bus, and the plurality of first electrode strips are arranged in parallel along the first direction; a plurality of second electrode strips connected to the second bus, and the plurality of second electrode strips are arranged in parallel along the first direction, the first electrode strips and the second electrode strips are alternately placed, and the first electrode strips and the second electrode strips have an overlapping area along the first direction.

[0019] Correspondingly, the technical solution of the present invention also provides a method for forming a surface acoustic wave resonator device, including: providing a piezoelectric substrate, the piezoelectric substrate having a first side and a second side opposite to each other, the piezoelectric substrate including a first device region, a second device region and an isolation region arranged along a first direction, the isolation region being located between the first device region and the second device region; forming a first portion in the piezoelectric substrate, the first portion being located in the isolation region, and the first portion having doped particles therein; forming a first electrode structure on the first device region, the first electrode structure being located on the first side; and forming a second electrode structure on the second device region, the second electrode structure being located on the first side.

[0020] Optionally, the method for forming the first portion includes: performing an implantation process of doping particles from the second side of the isolation region to the first side to form the first portion.

[0021] Optionally, the first part includes: a plurality of layers of sub-parts, each layer of the sub-parts contains doped particles, and the doped particles in adjacent sub-parts are different.

[0022] Optionally, the implantation depths of the doping particles in the sub-portions of different layers are different.

[0023] Optionally, after forming the first electrode structure and the second electrode structure, the method further includes: forming a second portion in the piezoelectric substrate, the second portion being located in the first device region, the second device region and the isolation region, and the first portion being located between the second portion and a first side surface of the piezoelectric substrate.

[0024] Optionally, the method for forming the second portion includes: performing an implantation process of doping particles from the first device region, the second device region, and the second side of the isolation region toward the first side to form the second portion.

[0025] Optionally, the method for forming the second portion includes: roughening the second side surface of the piezoelectric substrate to form an irregular concave-convex structure.

[0026] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0027] In the surface acoustic wave resonant device of the technical solution of the present invention, the piezoelectric substrate includes the first part located in the isolation area and having doped particles. The leakage wave excited by the first electrode structure or the second electrode structure on the adjacent device area and the reflected body wave reflected by the leakage wave in the piezoelectric substrate will be scattered after passing through the isolation area and contacting the first part, which can suppress the intensity of the reflected body wave transmitted to the adjacent device area, and further reduce the interference caused by the reflected body wave entering the adjacent device area, thereby reducing the clutter introduced into the filter passband, reducing the influence of body wave radiation on the Q value of the resonant device, and improving the performance of the surface acoustic wave resonant device.

[0028] Furthermore, the first part is a multi-layer structure; the first part includes: a plurality of layers of sub-parts, each layer of the sub-parts has doped particles, and the doped particles in adjacent sub-parts are different. By forming the sub-parts with different doped particles, the selection range of the reflected body wave frequency can be increased, the effect of scattering the reflected body wave can be improved, the interference caused by the reflected body wave entering the adjacent device area can be further reduced, and the influence of the body wave radiation on the Q value of the resonant device can be reduced.

[0029] Furthermore, the piezoelectric substrate further includes a second portion, the second portion is located in the first device region, the second device region and the isolation region, and the first portion is located between the second portion and the first side surface of the piezoelectric substrate. The second portion can scatter or diffusely reflect leakage waves excited by the first electrode structure and the second electrode structure, thereby reducing the influence of body wave radiation on the Q value of the resonant device.

[0030] Furthermore, the spacing between the first part and the surface of the piezoelectric substrate located on the second side is 10 microns to 100 microns. When the spacing is greater than 100 microns, the injection depth of the first part is large, requiring greater particle injection energy to complete, making the particle injection process more difficult; when the spacing is less than 10 microns, the injection depth of the first part is small, which is easy to cause structural defects (such as lattice fracture) of the first part, thereby affecting the effect of the scattering body wave of the first part.

[0031] In the method for forming a surface acoustic wave resonant device of the technical solution of the present invention, the piezoelectric substrate includes the first part located in the isolation region and having doped particles. The leakage wave excited by the first electrode structure or the second electrode structure on the adjacent device region and the reflected body wave reflected by the leakage wave in the piezoelectric substrate will be scattered after passing through the isolation region and contacting the first part, which can suppress the intensity of the reflected body wave transmitted to the adjacent device region, and further reduce the interference caused by the reflected body wave entering the adjacent device region, thereby reducing the clutter introduced into the filter passband, reducing the influence of body wave radiation on the Q value of the resonant device, and improving the performance of the surface acoustic wave resonant device.

[0032] Furthermore, the first part is a multi-layer structure; the first part includes: a plurality of layers of sub-parts, each layer of the sub-parts has doped particles, and the doped particles in adjacent sub-parts are different. By forming the sub-parts with different doped particles, the selection range of the reflected body wave frequency can be increased, the effect of scattering the reflected body wave can be improved, the interference caused by the reflected body wave entering the adjacent device area can be further reduced, and the influence of the body wave radiation on the Q value of the resonant device can be reduced.

[0033] Furthermore, the piezoelectric substrate further includes a second portion, the second portion is located in the first device region, the second device region and the isolation region, and the first portion is located between the second portion and the first side surface of the piezoelectric substrate. The second portion can scatter or diffusely reflect leakage waves excited by the first electrode structure and the second electrode structure, thereby reducing the influence of body wave radiation on the Q value of the resonant device. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 and Figure 2 It is a schematic diagram of the structure of a surface acoustic wave resonance device;

[0035] Figures 3 to 6 is a structural schematic diagram of each step of a method for forming a surface acoustic wave resonator device in an embodiment of the present invention;

[0036] Figure 7 is a schematic structural diagram of a surface acoustic wave resonance device in another embodiment of the present invention;

[0037] Figure 8 is a schematic structural diagram of a surface acoustic wave resonance device in another embodiment of the present invention;

[0038] Fig. 9 It is a schematic structural diagram of a surface acoustic wave resonance device in another embodiment of the present invention. DETAILED DESCRIPTION

[0039] As described in the background art, there are still many problems with the surface acoustic wave resonance device, which will be described in detail below with reference to the accompanying drawings.

[0040] Figure 1 and Figure 2 It is a structural schematic diagram of a surface acoustic wave resonance device.

[0041] Please refer to Figure 1 and Figure 2 , Figure 2 yes Figure 1A schematic cross-sectional view along line AA in FIG. 1 shows a surface acoustic wave resonance device, comprising: a piezoelectric substrate 100, wherein the piezoelectric substrate 100 has a first side 100a and a second side 100b opposite to each other, wherein the piezoelectric substrate 100 comprises a first device region A1, a second device region A2 and an isolation region B1 arranged along a first direction X, wherein the isolation region B1 is located between the first device region A1 and the second device region A2; a surface of the piezoelectric substrate 100 located at the second side 100b is a rough surface 104, wherein the rough surface 104 has an irregular concave-convex arrangement; a first electrode structure 101 located on the first device region A1, wherein the first electrode structure 101 is located at the first side 100a; and a second electrode structure 102 located on the second device region A2, wherein the second electrode structure 102 is located at the first side 100a.

[0042] Currently, the rough surface 104 is generally formed on the surface of the piezoelectric substrate 100 located on the second side 100b through roughening and grinding. The rough surface 104 enhances the scattering of energy leaked from the first side 100a to the second side 100b by the first electrode structure 101 and the second electrode structure 102, thereby reducing the influence of body wave radiation on the Q value of the resonant device.

[0043] However, when the two resonators formed by the first electrode structure 101 and the second electrode structure 102 are close to each other, their diffuse reflected body wave radiation will interfere with each other, which will cause the filter passband to have clutter, affecting the performance of the surface acoustic wave resonance device.

[0044] On this basis, the present invention provides a surface acoustic wave resonance device and a method for forming the same, wherein the piezoelectric substrate includes the first portion located in the isolation region and having doped particles, and the leakage wave excited by the first electrode structure or the second electrode structure on the adjacent device region and the reflected body wave reflected by the leakage wave in the piezoelectric substrate will be scattered after passing through the isolation region and contacting the first portion, thereby suppressing the intensity of the reflected body wave transmitted to the adjacent device region, and further reducing the interference caused by the reflected body wave entering the adjacent device region, thereby reducing the clutter introduced into the filter passband, reducing the influence of body wave radiation on the Q value of the resonance device, and improving the performance of the surface acoustic wave resonance device.

[0045] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0046] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0047] Figures 3 to 6 It is a structural schematic diagram of each step of the method for forming a surface acoustic wave resonance device in an embodiment of the present invention.

[0048] Please refer to Figure 3 A piezoelectric substrate 200 is provided, wherein the piezoelectric substrate 200 has a first side 200a and a second side 200b opposite to each other, and the piezoelectric substrate 200 includes a first device region A1, a second device region A2 and an isolation region B1 arranged along a first direction X, and the isolation region B1 is located between the first device region A1 and the second device region A2.

[0049] The material of the piezoelectric substrate 200 includes: lithium tantalate, lithium niobate, lead zirconate titanate, lead magnesium niobate-lead titanate, aluminum nitride, aluminum nitride alloy, gallium nitride or zinc oxide.

[0050] In this embodiment, the material of the piezoelectric substrate 200 is lithium niobate.

[0051] It should be noted that, in this embodiment, the first device area A1 and the second device area A2 are adjacent device areas. In subsequent processes, a first resonant device is formed on the first device area A1, and a second resonant device is formed on the second device area A2.

[0052] Please refer to Figure 4 A first portion 201 is formed in the piezoelectric substrate 200 , wherein the first portion 201 is located in the isolation region B1 , and the first portion 201 has doped particles therein.

[0053] In this embodiment, the method for forming the first portion 201 includes: performing an implantation process of doping particles from the second side 200 b of the isolation region B1 to the first side 200 a to form the first portion 201 .

[0054] In other embodiments, the method for forming the first portion 201 further includes: implanting doping particles from the first side 200 a of the isolation region B1 toward the second side 200 b to form the first portion 201 .

[0055] In this embodiment, the first portion 201 is a single-layer structure.

[0056] In this embodiment, the doping particles include hydrogen ions or helium ions.

[0057] In this embodiment, the spacing dimension d1 between the first portion 201 and the surface of the piezoelectric substrate 200 located at the second side 200b is 10 microns to 100 microns. When the spacing dimension d1 is greater than 100 microns, the injection depth of the first portion 201 is large, and a larger particle injection energy is required to complete the injection, which increases the difficulty of the particle injection process; when the spacing dimension d1 is less than 10 microns, the injection depth of the first portion 201 is small, which is easy to cause structural defects (such as lattice fracture) of the first portion 201, thereby affecting the effect of the scattering body wave of the first portion 201.

[0058] Please refer to Figure 5 and Figure 6 , Figure 6 yes Figure 5 In the cross-sectional diagram along line AA, a first electrode structure 202 is formed on the first device area A1, and the first electrode structure 202 is located on the first side 200a; a second electrode structure 203 is formed on the second device area A2, and the second electrode structure 203 is located on the first side 200a.

[0059] The piezoelectric substrate 200 includes the first part 201 located in the isolation area B1 and having doped particles. The leakage wave excited by the first electrode structure 202 or the second electrode structure 203 on the adjacent device area and the reflected body wave reflected by the leakage wave in the piezoelectric substrate 200 will be scattered after passing through the isolation area B1 and contacting the first part 201, which can suppress the intensity of the reflected body wave transmitted to the adjacent device area, and further reduce the interference caused by the reflected body wave entering the adjacent device area, thereby reducing the clutter introduced into the filter passband, reducing the influence of body wave radiation on the Q value of the resonance device, and improving the performance of the surface acoustic wave resonance device.

[0060] In this embodiment, the first electrode structure 202 and the second electrode structure 203 both include: a first bus 2021 and a second bus 2022 extending along the first direction X and arranged in parallel along the second direction Y, the first direction X being perpendicular to the second direction Y; a plurality of first electrode strips 2023 connected to the first bus 2021, the plurality of first electrode strips 2023 being arranged in parallel along the first direction X; a plurality of second electrode strips 2024 connected to the second bus 2022, the plurality of second electrode strips 2024 being arranged in parallel along the first direction X, the first electrode strips 2023 and the second electrode strips 2024 being staggered, and the first electrode strips 2023 and the second electrode strips 2024 having overlapping areas along the first direction X.

[0061] In this embodiment, the material of the first electrode structure 202 and the second electrode structure 203 includes but is not limited to one of the following: molybdenum, tungsten, copper, platinum, rhenium, osmium, iridium, tantalum, gold, and hafnium.

[0062] Please continue to refer to Figure 5 and Figure 6 In this embodiment, after the first electrode structure 202 and the second electrode structure 203 are formed, a metal layer 204 is formed on the first bus 2021 and the second bus 2022, and the metal layer 204 is located on the first side 200a.

[0063] By adding the metal layer 204 on the first bus 2021 and the second bus 2022 , the resistance of the bus bars of the first electrode structure 202 and the second electrode structure 203 can be effectively reduced, thereby further improving the electrical performance of the surface acoustic wave resonator device.

[0064] In this embodiment, the material of the metal layer 204 includes but is not limited to one of the following: copper, aluminum and gold.

[0065] Correspondingly, the present invention also provides a surface acoustic wave resonance device in the embodiment, please continue to refer to Figure 6 , comprising: a piezoelectric substrate 200, the piezoelectric substrate 200 having a first side 200a and a second side 200b opposite to each other, the piezoelectric substrate 200 comprising a first device region A1, a second device region A2 and an isolation region B1 arranged along a first direction X, the isolation region B1 being located between the first device region A1 and the second device region A2; a first electrode structure 202 located on the first device region A1, the first electrode structure 202 being located on the first side 200a; a second electrode structure 203 located on the second device region A2, the second electrode structure 203 being located on the first side 200a; the piezoelectric substrate 200 comprising a first portion 201, the first portion 201 being located in the isolation region B1, and the first portion 201 having doped particles therein.

[0066] The piezoelectric substrate 200 includes the first part 201 located in the isolation area B1 and having doped particles. The leakage wave excited by the first electrode structure 202 or the second electrode structure 203 on the adjacent device area and the reflected body wave reflected by the leakage wave in the piezoelectric substrate 200 will be scattered after passing through the isolation area B1 and contacting the first part 201, which can suppress the intensity of the reflected body wave transmitted to the adjacent device area, and further reduce the interference caused by the reflected body wave entering the adjacent device area, thereby reducing the clutter introduced into the filter passband, reducing the influence of body wave radiation on the Q value of the resonance device, and improving the performance of the surface acoustic wave resonance device.

[0067] In this embodiment, the first portion 201 is a single-layer structure.

[0068] In this embodiment, the doping particles include hydrogen ions or helium ions.

[0069] Please continue to refer to Figure 4 In this embodiment, the spacing dimension between the first portion 201 and the surface of the piezoelectric substrate 200 located at the second side 200b is 10 microns to 100 microns. When the spacing dimension d1 is greater than 100 microns, the injection depth of the first portion 201 is large, and a larger particle injection energy is required to complete the injection, which increases the difficulty of the particle injection process; when the spacing dimension d1 is less than 10 microns, the injection depth of the first portion 201 is small, which is easy to cause structural defects (such as lattice fracture) of the first portion 201, thereby affecting the effect of the scattering body wave of the first portion 201.

[0070] Please continue to refer to Figure 5 In this embodiment, the first electrode structure 202 and the second electrode structure 203 both include: a first bus 2021 and a second bus 2022 extending along the first direction X and arranged in parallel along the second direction Y, the first direction X being perpendicular to the second direction Y; a plurality of first electrode strips 2023 connected to the first bus 2021, the plurality of first electrode strips 2023 being arranged in parallel along the first direction X; a plurality of second electrode strips 2024 connected to the second bus 2022, the plurality of second electrode strips 2024 being arranged in parallel along the first direction X, the first electrode strips 2023 and the second electrode strips 2024 being arranged in an alternating manner, and the first electrode strips 2023 and the second electrode strips 2024 having an overlapping area along the first direction X.

[0071] Please continue to refer to Figure 6 In this embodiment, it further includes: a metal layer 204 located on the first bus 2021 and the second bus 2022, and the metal layer 204 is located on the first side 200a. By adding the metal layer 204 on the first bus 2021 and the second bus 2022, the resistance of the bus bars of the first electrode structure 202 and the second electrode structure 203 can be effectively reduced, thereby further improving the electrical performance of the surface acoustic wave resonator device.

[0072] Figure 7 It is a schematic structural diagram of a surface acoustic wave resonance device in another embodiment of the present invention.

[0073] This embodiment is based on the above embodiment ( Figure 3) is used to continue to describe the method for forming a surface acoustic wave resonator device, and the rest is the same as the above embodiment, except that: the first part 301 is a multi-layer structure. The following will be described in detail with reference to the accompanying drawings.

[0074] Please refer to Figure 7 A first portion 301 is formed in the piezoelectric substrate 200 , wherein the first portion 301 is located in the isolation region B1 , and the first portion 301 has doped particles therein.

[0075] In this embodiment, the first part 301 is a multi-layer structure. Specifically, the first part 301 includes: several layers of sub-parts (301a, 301b), each layer of the sub-parts (301a, 301b) has doped particles, and the doped particles in adjacent sub-parts (301a, 301b) are different.

[0076] By forming the sub-sections (301a, 301b) with different doped particles, the selection range of the reflected body wave frequency can be increased, the effect of scattering the reflected body wave can be improved, the interference caused by the reflected body wave entering the adjacent device area can be further reduced, and the influence of the body wave radiation on the Q value of the resonance device can be reduced.

[0077] In other embodiments, the first portion 301 may include more than two layers of sub-portions.

[0078] In this embodiment, the method for forming the first portion 301 includes: performing several implantation processes of different doping particles from the second side 200 b of the isolation region B1 to the first side 200 a , with each implantation depth of the doping particles being different, to form the first portion 301 .

[0079] In this embodiment, the implantation depth of the sub-portion 301 b is greater than the implantation depth of the sub-portion 301 a .

[0080] In this embodiment, the doping particles in the adjacent sub-portions (301a, 301b) are different, including: the particle radii of the doping particles in the adjacent sub-portions (301a, 301b) are different.

[0081] In this embodiment, the doping particles include hydrogen ions or helium ions.

[0082] In this embodiment, the specific structure formation methods of the first electrode structure 202 and the second electrode structure 203 are the same as those in the above embodiment. Figures 5 and 6 As well as the related instructions, they will not be repeated here.

[0083] Correspondingly, the present invention also provides a surface acoustic wave resonance device in the embodiment, please continue to refer to Figure 7The rest of the structure is the same as the surface acoustic wave resonance device described in the above embodiment, except that: the first part 301 is a multi-layer structure.

[0084] In this embodiment, the first portion 301 includes: a plurality of layers of sub-portions (301a, 301b), each layer of the sub-portions (301a, 301b) has doped particles, and the doped particles in adjacent sub-portions (301a, 301b) are different.

[0085] By forming the sub-sections (301a, 301b) with different doped particles, the selection range of the reflected body wave frequency can be increased, the effect of scattering the reflected body wave can be improved, the interference caused by the reflected body wave entering the adjacent device area can be further reduced, and the influence of the body wave radiation on the Q value of the resonance device can be reduced.

[0086] In other embodiments, the first portion 301 may include more than two layers of sub-portions.

[0087] In this embodiment, the doping particles in the adjacent sub-portions (301a, 301b) are different, including: the particle radii of the doping particles in the adjacent sub-portions (301a, 301b) are different.

[0088] In this embodiment, the doping particles include hydrogen ions or helium ions.

[0089] Figure 8 It is a schematic structural diagram of a surface acoustic wave resonance device in another embodiment of the present invention.

[0090] This embodiment is based on the above embodiment ( Figure 6 and Figure 7 ), the method for forming a surface acoustic wave resonator device is further described based on the above embodiment, and the rest is the same as the above embodiment, except that: a second portion is formed in the piezoelectric substrate 200, and the second portion includes an irregular concave-convex structure. The following will be described in detail with reference to the accompanying drawings.

[0091] Please refer to Figure 8 After forming the first electrode structure 202 and the second electrode structure 203, a second portion 401 is formed in the piezoelectric substrate 200, the second portion 401 is located in the first device area A1, the second device area A2 and the isolation area B1, and the first portion 201 is located between the second portion 401 and the surface of the first side 200a of the piezoelectric substrate 200.

[0092] The second portion 401 can diffusely reflect the leakage waves excited by the first electrode structure 202 and the second electrode structure 203, thereby reducing the influence of body wave radiation on the Q value of the resonance device.

[0093] In this embodiment, the second portion 401 is located on the surface of the second side 200 b of the piezoelectric substrate 200 .

[0094] In this embodiment, the method for forming the second portion 401 includes: roughening the surface of the second side 200 b of the piezoelectric substrate 200 to form an irregular concave-convex structure.

[0095] In this embodiment, the method of roughening the surface of the second side 200 b of the piezoelectric substrate 200 includes: grinding the surface of the second side 200 b of the piezoelectric substrate 200 .

[0096] Correspondingly, the present invention also provides a surface acoustic wave resonance device in the embodiment, please continue to refer to Figure 8 The rest of the structure is the same as the surface acoustic wave resonator device described in the above embodiment, except that: the piezoelectric substrate 200 further includes a second portion 401, and the second portion 401 includes an irregular concave-convex structure.

[0097] In this embodiment, the second portion 401 is located in the first device region A1 , the second device region A2 , and the isolation region B1 , and the first portion 201 is located between the second portion 401 and the surface of the first side 200 a of the piezoelectric substrate 200 .

[0098] The second portion 401 can diffusely reflect the leakage waves excited by the first electrode structure 202 and the second electrode structure 203, thereby reducing the influence of body wave radiation on the Q value of the resonance device.

[0099] In this embodiment, the second portion 401 is located on the surface of the second side 200 b of the piezoelectric substrate 200 .

[0100] Fig. 9 It is a schematic structural diagram of a surface acoustic wave resonance device in another embodiment of the present invention.

[0101] This embodiment is based on the above embodiment ( Figure 6 and Figure 7 ), the method for forming a surface acoustic wave resonator device is further described based on the above embodiment, and the rest is the same as the above embodiment, except that: a second portion is formed in the piezoelectric substrate 200, and the second portion has doped particles. The following will be described in detail with reference to the accompanying drawings.

[0102] Please refer to Fig. 9 , doping particles are implanted from the first device region A1 , the second device region A2 , and the second side 200 b of the isolation region B1 toward the first side 200 a to form the second portion 501 .

[0103] In this embodiment, the second portion 501 is exposed on the surface of the second side 200 b of the piezoelectric substrate 200 .

[0104] In other embodiments, the second portion 501 may also be completely located within the piezoelectric substrate 200 .

[0105] Since the particle-doped second portion 501 can scatter the leakage waves excited by the first electrode structure 202 and the second electrode structure 203, the influence of the body wave radiation on the Q value of the resonant device is reduced. In addition, by directly forming the second portion 501 in the piezoelectric substrate 200, the process step of roughening the surface of the second side 200b of the piezoelectric substrate 200 is omitted, thereby improving the efficiency of the process.

[0106] In this embodiment, the doping particles in the second portion 501 are the same as at least part of the doping particles in the first portion 201 (301). Specifically, when the first portion 201 is a single-layer structure, the doping particles in the second portion 501 are the same as the doping particles in the first portion 201; when the first portion 301 is a multi-layer structure, the doping particles in the portion (301a) adjacent to the first portion 301 and the second portion 501 are the same as the doping particles in the second portion 501. Therefore, it is not necessary to replace ions when forming the second portion 501, further improving the efficiency of the process.

[0107] In other embodiments, the doping particles in the second portion 501 are different from the doping particles in the first portion 201 ( 301 ).

[0108] In this embodiment, the doping particles include hydrogen ions or helium ions.

[0109] Correspondingly, the present invention also provides a surface acoustic wave resonance device in the embodiment, please continue to refer to Fig. 9 The rest of the structure is the same as the surface acoustic wave resonator device described in the above embodiment, except that: the piezoelectric substrate 200 includes a second portion 501, and the second portion 501 has doped particles therein.

[0110] Since the particle-doped second portion 501 can scatter the leakage waves excited by the first electrode structure 202 and the second electrode structure 203, the influence of the body wave radiation on the Q value of the resonant device is reduced. In addition, by directly forming the second portion 501 on the surface of the piezoelectric substrate 200 located on the second side 200b, the process step of roughening the surface of the piezoelectric substrate 200 located on the second side 200b is omitted, thereby improving the efficiency of the process.

[0111] In this embodiment, the doping particles in the second portion 501 are the same as at least part of the doping particles in the first portion 201 (301). Specifically, when the first portion 201 is a single-layer structure, the doping particles in the second portion 501 are the same as the doping particles in the first portion 201; when the first portion 301 is a multi-layer structure, the doping particles in the portion (301a) adjacent to the first portion 301 and the second portion 501 are the same as the doping particles in the second portion 501. Therefore, it is not necessary to replace ions when forming the second portion 501, further improving the efficiency of the process.

[0112] In other embodiments, the doping particles in the second portion 501 are different from the doping particles in the first portion 201 ( 301 ).

[0113] In this embodiment, the doping particles include hydrogen ions or helium ions.

[0114] It should be understood that the examples and embodiments herein are merely illustrative and that various modifications and corrections may be made by those skilled in the art without departing from the spirit and scope of the present invention as defined in this application and the appended claims.

Claims

1. A surface acoustic wave resonance device, characterized in that: include: A piezoelectric substrate having a first side and a second side opposite to each other, the piezoelectric substrate comprising a first device region, a second device region and an isolation region arranged along a first direction, the isolation region being located between the first device region and the second device region; a first electrode structure located on the first device region, the first electrode structure being located on the first side; a second electrode structure located on the second device region, the second electrode structure being located on the first side; The piezoelectric substrate includes a first portion, the first portion is located in the isolation region, and the first portion has doping particles therein.

2. The surface acoustic wave resonator device according to claim 1, characterized in that: The first part includes: a plurality of layers of sub-parts, each layer of the sub-parts has doped particles therein, and the doped particles in adjacent sub-parts are different.

3. The surface acoustic wave resonator device according to claim 2, characterized in that: The doping particles in adjacent sub-divisions are different includes: the particle radii of the doping particles in adjacent sub-divisions are different.

4. The surface acoustic wave resonator device according to claim 1, characterized in that: The piezoelectric substrate further includes a second portion located in the first device region, the second device region, and the isolation region, and the first portion is located between the second portion and a first side surface of the piezoelectric substrate.

5. The surface acoustic wave resonator device according to claim 4, characterized in that: The second portion has doping particles therein.

6. The surface acoustic wave resonator device according to claim 5, characterized in that: The doping particles in the second portion are different from the doping particles in the first portion.

7. The surface acoustic wave resonator device according to claim 5, characterized in that: The doping particles in the second portion are the same as at least some of the doping particles in the first portion.

8. The surface acoustic wave resonator device according to claim 7, characterized in that: Doping particles in a portion of the first portion adjacent to the second portion are the same as doping particles in the second portion.

9. The surface acoustic wave resonator device according to claim 1, 2 or 5, characterized in that: The doping particles include hydrogen ions or helium ions.

10. The surface acoustic wave resonator device according to claim 4, characterized in that: The second portion is located on a second side surface of the piezoelectric substrate.

11. The surface acoustic wave resonator device according to claim 10, characterized in that: The second portion includes an irregular concave-convex structure.

12. The surface acoustic wave resonator device according to claim 1, characterized in that: The distance between the first portion and the second side surface of the piezoelectric substrate is 10 micrometers to 100 micrometers.

13. The surface acoustic wave resonator device according to claim 1, characterized in that: The first electrode structure and the second electrode structure both include: a first bus and a second bus extending along the first direction and arranged in parallel along the second direction, the first direction being perpendicular to the second direction; a plurality of first electrode strips connected to the first bus, the plurality of first electrode strips being arranged in parallel along the first direction; a plurality of second electrode strips connected to the second bus, the plurality of second electrode strips being arranged in parallel along the first direction, the first electrode strips and the second electrode strips being arranged alternately, and the first electrode strips and the second electrode strips having an overlapping area along the first direction.

14. A method for forming a surface acoustic wave resonator device, characterized in that: include: Providing a piezoelectric substrate, the piezoelectric substrate having a first side and a second side opposite to each other, the piezoelectric substrate comprising a first device region, a second device region and an isolation region arranged along a first direction, the isolation region being located between the first device region and the second device region; forming a first portion in the piezoelectric substrate, the first portion being located in the isolation region and having doped particles therein; forming a first electrode structure on the first device region, wherein the first electrode structure is located on the first side; A second electrode structure is formed on the second device region, wherein the second electrode structure is located on the first side.

15. The method for forming a surface acoustic wave resonator device according to claim 14, wherein: The method for forming the first portion includes: performing an implantation process of doping particles from the second side of the isolation region to the first side to form the first portion.

16. The method for forming a surface acoustic wave resonator device according to claim 15, wherein: The first part includes: a plurality of layers of sub-parts, each layer of the sub-parts has doped particles therein, and the doped particles in adjacent sub-parts are different.

17. The method for forming a surface acoustic wave resonator device according to claim 16, wherein: The implantation depths of the doping particles in the sub-portions of different layers are different.

18. The method for forming a surface acoustic wave resonator device according to claim 15, wherein: After forming the first electrode structure and the second electrode structure, the method further includes: forming a second portion in the piezoelectric substrate, the second portion being located in the first device region, the second device region and the isolation region, and the first portion being located between the second portion and a first side surface of the piezoelectric substrate.

19. The method for forming a surface acoustic wave resonator device according to claim 18, wherein: The method for forming the second portion includes: performing an implantation process of doping particles from the first device region, the second device region, and the second side of the isolation region toward the first side to form the second portion.

20. The method for forming a surface acoustic wave resonator device according to claim 18, wherein: The method for forming the second portion includes: roughening the second side surface of the piezoelectric substrate to form an irregular concave-convex structure.

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