TPoS resonator with low anchor loss and high quality factor

Abstract

The invention relates to a TPoS resonator with low anchor loss and high quality factor. The resonator comprises a resonator body, the resonator body comprises a resonance substrate, a resonance body and a supporting beam unit, the supporting beam unit at least comprises two supporting beams distributed on the two sides of the resonance body, and each supporting beam supports a resonance extraction electrode adaptively and electrically connected with the resonance body; the phononic crystal unit comprises at least one one-dimensional phononic crystal used for forming an acoustic reflection area, one one-dimensional phononic crystal is prepared in a supporting beam, and the working frequency of the resonance body is located in an acoustic band gap formed by the one-dimensional phononic crystal; the one-dimensional phonon crystal comprises a plurality of phonon unit cells which are connected in sequence, and the arrangement direction of the phonon unit cells in the one-dimensional phonon crystal is consistent with the direction of the supporting beam pointing to the resonant body; the one-dimensional photonic crystal is adopted, so that the anchor loss and the stray mode can be effectively reduced, and the quality factor of the resonator is effectively improved.

Description

Technical Field

[0001] The present invention relates to a resonator, in particular to a TPoS resonator with low anchor loss and high quality factor. Background Art

[0002] The TPoS resonator is a type of bulk acoustic wave (BAW) resonator, which has the characteristics of small size, low energy consumption, and high frequency. However, it has the problem of low quality factor Q caused by anchor loss and spurious modes, which reduces the performance of the resonator itself or its application in fields such as oscillators.

[0003] In the existing technology, there are many technical means to improve the quality factor Q value of TPoS resonators, including the use of peripheral frame structure, optimization of support beam size, optimization of electrode shape, double convex edge structure, etc. However, for other types of resonators, these technical means are difficult to guarantee the same effect. Therefore, a more widely used method to improve the quality factor Q is needed. The emergence of phononic crystals has brought a solution to improving the quality factor of resonators.

[0004] Phononic crystals, as composite structures that block the propagation of sound waves within a specific frequency range, are often used in applications such as vibration isolation and vibration reduction. However, most research on phononic crystals focuses on two-dimensional phononic crystals. Resonators using two-dimensional phononic crystals have complex preparation processes and still suffer from problems such as severe stray modes and limited improvement in the quality factor (Q), making it difficult to meet actual application needs. Summary of the Invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a TPoS resonator with low anchor loss and high quality factor. The TPoS resonator adopts a one-dimensional phononic crystal, which can effectively reduce the anchor loss and stray modes and effectively improve the quality factor of the resonator.

[0006] According to the technical solution provided by the present invention, a TPoS resonator with low anchor loss and high quality factor comprises:

[0007] The resonator body includes a resonant substrate, a resonant body prepared on the resonant substrate, and a support beam unit for supporting a resonant extraction electrode, wherein:

[0008] The support beam unit includes at least two support beams distributed on both sides of the resonator, and each support beam supports a resonant extraction electrode adapted to be electrically connected to the resonator;

[0009] The phononic crystal unit includes at least one one-dimensional phononic crystal for forming an acoustic reflection region, wherein:

[0010] A one-dimensional phononic crystal is prepared in a support beam, and the operating frequency of the resonator is located within the acoustic band gap formed by the one-dimensional phononic crystal;

[0011] The one-dimensional phononic crystal includes a plurality of phononic unit cells connected in sequence, and the arrangement direction of the phononic unit cells in the one-dimensional phononic crystal is consistent with the direction of the support beam pointing to the resonator.

[0012] A one-dimensional phononic crystal is prepared in each support beam, and the arrangement length of the phononic unit cells in the one-dimensional phononic crystal is no longer than the length of the support beam;

[0013] The shapes of the phonon unit cell include a cross, where

[0014] When the shape of the phonon unit cell is a cross, the phonon unit cell includes a cross-shaped phonon unit cell plate and a unit cell scatterer that penetrates the phonon crystal plate and is in a hollow state.

[0015] The phonon unit cell is connected to the supporting beam via the phonon unit cell plate, and adjacent phonon unit cells are connected into one piece via corresponding phonon unit cell plates.

[0016] The phononic unit cell plate includes four unit cell wings that are evenly and symmetrically distributed, wherein:

[0017] The phonon unit cell is fixedly connected to the support beam via a unit cell wing, and is connected to the unit cell wing of the adjacent phonon unit cell via the corresponding unit cell wing;

[0018] The unit cell scatterer includes a unit cell scattering main hole located in the central area of ​​the phonon unit cell plate and unit cell scattering auxiliary holes uniformly and symmetrically distributed on the outer circle of the unit cell scattering main hole.

[0019] Each unit cell scattering auxiliary hole is distributed in the corresponding unit cell wing, and the unit cell scattering auxiliary holes are connected to the unit cell scattering main hole;

[0020] The aperture of the unit cell scattering main hole is larger than the aperture of the unit cell scattering auxiliary hole.

[0021] It also includes an in-plane acoustic reflection unit arranged on the resonant substrate, wherein,

[0022] The in-plane acoustic reflection unit comprises at least two in-plane acoustic reflection grooves etched and prepared in the resonant substrate, wherein:

[0023] The in-plane acoustic reflection grooves correspond to the support beams one-to-one, and the in-plane acoustic reflection grooves are located outside the corresponding support beams;

[0024] The shape of the in-plane acoustic reflection groove is similar to the shape of the sound wave before it propagates through the resonator to the air interface, so that the sound wave returns to the resonator in the same phase after being reflected by the in-plane acoustic reflection groove.

[0025] The shape of the in-plane acoustic reflection groove is arc-shaped, wherein,

[0026] When the shape of the in-plane acoustic reflection groove is arc-shaped, the arc-shaped openings of the in-plane acoustic reflection groove all point to the resonator, and when the support beam is projected onto the corresponding in-plane acoustic reflection groove, the projection of the support beam is located in the in-plane acoustic reflection groove.

[0027] The resonator includes a resonant bottom electrode disposed on a resonant substrate, a resonant piezoelectric layer disposed on the resonant bottom electrode, and a resonant top electrode disposed on the resonant piezoelectric layer, wherein:

[0028] The resonant top electrode includes a current collecting unit and an interdigital electrode unit adapted to be connected to the current collecting unit, wherein:

[0029] The busbar unit includes two resonant busbars.

[0030] The interdigital electrode unit includes interdigital electrodes electrically connected to corresponding resonant bus bars, and each interdigital electrode is configured to have a main mode excitation enhancement state, wherein,

[0031] Based on the main mode excitation enhancement state of each interdigital electrode, the parasitic charges generated by connecting the interdigital electrodes to the resonant bus bar are concentrated in the central area of ​​the current interdigital electrodes.

[0032] Configuring the interdigital electrodes to have a main modal excitation enhancement state at least includes configuring the widths at both ends of the interdigital electrodes to be smaller than the width at the middle of the interdigital electrodes.

[0033] The resonant substrate at least includes an SOI substrate, wherein:

[0034] When the resonant substrate is an SOI substrate, a resonant separation groove is etched in the resonant substrate, and the bottom silicon of the resonant substrate is exposed through the groove bottom of the resonant separation groove, so that the SOI substrate is divided into at least a resonant support region located within the resonant separation groove, a lead connection region located outside the resonant separation groove, and a support beam region for forming a support beam by using the resonant separation groove;

[0035] The resonator is prepared on the functional silicon layer in the resonance support area, and the support beam is formed by the functional silicon layer in the support beam area, and the functional silicon layer in the support beam is connected to the functional silicon layer in the resonance support area.

[0036] When preparing a one-dimensional phononic crystal in a support beam, the functional silicon layer in the support beam is patterned to form a number of phononic crystal cells arranged in sequence after patterning. Thereafter, the crystal cell scatterers in the phononic crystal cell are used to sacrificially release the silicon dioxide layer corresponding to the crystal cell scatterers, and after the sacrificial release of the silicon dioxide layer, a hollow crystal cell scatterer is formed.

[0037] The length of the support beam is n*λ / 4, where n is an odd number and λ is the wavelength of the resonant sound wave when the resonator is working.

[0038] The advantages of the present invention are as follows: a one-dimensional phononic crystal is prepared in each support beam, and the prepared one-dimensional phononic crystal can form an acoustic reflection zone. When the one-dimensional phononic crystal is composed of multiple sequentially connected phononic unit cells, the one-dimensional phononic crystal has a complete acoustic band gap from 10 MHz to 13.31 MHz. Its band gap width is large, and it can effectively block and reflect sound waves within the acoustic band gap frequency range, thereby reducing anchor point loss. In addition, the acoustic reflection interface formed by the in-plane acoustic reflection groove can further improve the sound wave reflection effect, thereby maximizing the storage of main mode energy and improving the quality factor Q of the TPoS resonator.

[0039] By utilizing the characteristics of the complete acoustic band gap of one-dimensional phononic crystals, one-dimensional phononic crystals can be applied to various frequency devices, with a wider range of applications. In addition, each interdigital electrode is configured to have a state of enhanced main mode excitation to effectively reduce the generation of parasitic charges, which can significantly enhance the excitation of the main mode, reduce spurious modes, and further improve the quality factor Q of the TPoS resonator. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a three-dimensional diagram of an embodiment of the TPoS resonator of the present invention.

[0041] Figure 2 FIG. 1 is a schematic structural diagram of an embodiment of a TPoS resonator of the present invention.

[0042] Figure 3 The figure is a schematic diagram of an embodiment of the connection and coordination between the phonon unit cell, the phonon unit cell and the resonant substrate of the present invention.

[0043] Figure 4 Schematic diagram of an embodiment of the phonon unit cell of the present invention.

[0044] Figure 5 Schematic diagram of the acoustic band gap of the one-dimensional phononic crystal of the present invention.

[0045] Figure 6 A schematic diagram comparing the corresponding admittances of a TPoS resonator of the present invention and a conventional TPoS resonator according to an embodiment.

[0046] Explanation of the reference numerals: 1-functional silicon layer, 2-silicon dioxide layer, 3-bottom silicon, 4-lead electrode terminal, 5-ground electrode terminal, 6-middle part of the interdigitated electrode, 7-resonator, 8-resonant lead electrode, 9-bus bar, 10-connecting end of the interdigitated electrode, 11-non-connecting end of the interdigitated electrode, 12-support island, 13-resonant piezoelectric layer, 14-resonant separation groove, 15-support beam, 16-in-plane acoustic reflection groove, 17-one-dimensional phononic crystal, 18-phononic unit cell, 19-unit cell scattering main hole, 20-unit cell wing, 21-unit cell scattering auxiliary hole, 22-scattering transition hole. DETAILED DESCRIPTION

[0047] The present invention will be further described below with reference to specific drawings and embodiments.

[0048] In order to effectively reduce anchor loss and spurious modes and effectively improve the quality factor of the resonator, the present invention provides a TPoS resonator with low anchor loss and high quality factor. Specifically, the TPoS resonator includes:

[0049] The resonator body includes a resonant substrate, a resonant body 7 prepared on the resonant substrate, and a support beam unit for supporting a resonant extraction electrode 8, wherein:

[0050] The support beam unit comprises at least two support beams 15 distributed on both sides of the resonator 7, and each support beam 15 supports a resonant extraction electrode 8 adapted to be electrically connected to the resonator 7;

[0051] The phononic crystal unit includes at least one one-dimensional phononic crystal 17 for forming an acoustic reflection area, wherein:

[0052] A one-dimensional phononic crystal 17 is prepared in a support beam 15, and the operating frequency of the resonator 7 is located within the acoustic band gap formed by the one-dimensional phononic crystal 17;

[0053] The one-dimensional phononic crystal 17 includes a plurality of phononic unit cells 18 connected in sequence, and the arrangement direction of the phononic unit cells 18 in the one-dimensional phononic crystal 17 is consistent with the direction of the support beam 15 pointing to the resonator 7 .

[0054] It should be noted that the working mechanism of the TPoS resonator of the present invention is consistent with the working mechanism of the existing TPoS resonator. Therefore, in order to meet the working application requirements, the TPoS resonator of the present invention should include a resonator body, which is also the functional body of the TPoS resonator. Figure 1 and Figure 2An embodiment of the TPoS resonator of the present invention is shown in FIG. As can be seen from the figure, the resonator body generally includes a resonant substrate, a resonant body 7, and a support beam unit. The resonant substrate can adopt an existing commonly used substrate form, such as an SOI (Silicon-on-Insulator) substrate. Of course, the resonant substrate can also adopt other substrate forms, which can be selected according to needs. The specific description will be given below. The resonant body 7 is prepared on the resonant substrate and is generally located in the center area of ​​the resonant substrate. In order to facilitate the control of the working state of the resonant body 7, the resonant body 7 can be led out by two resonant lead-out electrodes 8, and the resonant lead-out electrodes 8 can be supported by the support beam unit.

[0055] Generally, the support beam unit should include at least two support beams 15, and the two support beams 15 are generally symmetrically distributed on both sides of the resonator 7. In specific implementation, two support beams 15 are preferably provided in the support beam unit. At this time, the two support beams 15 are coaxially distributed, and one support beam 15 is used to support one resonant extraction electrode 8. Figure 1 and Figure 2 In order to lead out the resonator 7, the resonance lead-out electrode 8 should be electrically connected to the resonator 7. For the specific electrical connection and the lead-out method adopted, please refer to the corresponding description below.

[0056] In order to reduce the anchor loss and improve the quality factor of the TPoS resonator, the present invention also includes a phononic crystal unit. Specifically, the phononic crystal unit includes at least one one-dimensional phononic crystal 17, wherein the one-dimensional phononic crystal 17 specifically refers to a phononic crystal in a one-dimensional state. An acoustic reflection area can be formed by the one-dimensional phononic crystal. The acoustic reflection area formed can reflect the sound waves leaked from the support beam 15 back into the resonator 7, so that the resonator 7 can store the main mode energy to the greatest extent, thereby reducing the anchor loss and improving the quality factor of the TPoS resonator.

[0057] In a specific implementation, the number of one-dimensional phononic crystals 17 in the phononic crystal unit is preferably two, and the two one-dimensional phononic crystals 17 in the phononic crystal unit are respectively prepared in the corresponding support beams 15, that is, two support beams 15 are preferably used, and a one-dimensional phononic crystal 17 is prepared in each support beam 15, such as Figure 1 and Figure 2 As shown; specifically, when preparing a one-dimensional phononic crystal 17 in each support beam 15, the one-dimensional phononic crystal 17 is located on one side of the support beam 15, and after the one-dimensional phononic crystal 17 is prepared, it should not affect the support of the corresponding resonant extraction electrode 8 by the support beam 15.

[0058] From the above description, it can be seen that the one-dimensional phononic crystal 17 is located on one side of the support beam 15. In specific implementation, two one-dimensional phononic crystals 17 can be located on the same side of the corresponding support beam 15, such as Figure 1 and Figure 2 In the embodiment, the two one-dimensional phononic crystals 17 are both located on the right side of the corresponding support beam 15. Of course, the two one-dimensional phononic crystals 17 can also be located on different sides of the two support beams 15. For example, one one-dimensional phononic crystal 17 can be located on the right side of the corresponding support beam 15. Figure 1 and Figure 2 On the right side of a support beam 15, another one-dimensional phononic crystal 17 is placed Figure 1 and Figure 2 The left side of the other support beam 15 can be selected according to needs.

[0059] It should be noted that in order to achieve effective reflection of sound waves, the operating frequency of the resonator 7 should be within the acoustic band gap of the one-dimensional phononic crystal 17. Therefore, the acoustic band gap corresponding to the one-dimensional phononic crystal 17 can be set according to the operating frequency of the resonator 7. In specific implementation, the one-dimensional phononic crystal 17 should include a plurality of phononic unit cells 18 connected in sequence. Figure 1 、 Figure 2 and Figure 3 An embodiment of a one-dimensional phononic crystal 17 including multiple phononic unit cells 18 is shown, wherein the phononic unit cell 18 is the smallest repeating unit in the one-dimensional phononic crystal 17, and the arrangement direction of the phononic unit cell 18 in the one-dimensional phononic crystal 17 is consistent with the length direction of the support beam 15, and is consistent with the direction of the support beam 15 pointing to the resonator 7.

[0060] In one embodiment of the present invention, a one-dimensional phononic crystal 17 is prepared in each support beam 15, and the arrangement length of the phononic unit cells 18 in the one-dimensional phononic crystal 17 is not greater than the length of the support beam 15;

[0061] The 18 shapes of the phononic unit cell include a cross shape, wherein,

[0062] When the shape of the phonon unit cell 18 is a cross, the phonon unit cell 18 includes a cross-shaped phonon unit cell plate and a unit cell scatterer that penetrates the phonon unit cell plate and is in a hollow state.

[0063] The phonon unit cells 18 are connected to the support beam 15 via the phonon unit cell plates, and adjacent phonon unit cells 18 are connected into one piece via corresponding phonon unit cell plates.

[0064] From the above description, it can be seen that in order to effectively improve the quality factor Q of the TPoS resonator, it is preferred to prepare a one-dimensional phononic crystal 17 in each support beam 15, and the phononic unit cells 18 in each one-dimensional phononic crystal 17 are arranged along the length direction of the support beam 15. However, the arrangement length of the phononic unit cells 18 in each one-dimensional phononic crystal 17 should not be greater than the length of the support beam 15 in which they are located, so as to improve the support strength of the support beam 15 for the resonant extraction electrode 18 while being able to reflect the sound waves. Specifically, the arrangement length of the phononic unit cells 18 in the one-dimensional phononic crystal 17 is the length of the one-dimensional phononic crystal 17 in which the phononic unit cells 18 are located. Figure 1 and Figure 2 FIG shows an embodiment in which the length of each one-dimensional phononic crystal 17 is smaller than the supporting beam 15 where it is located. Figure 1 and Figure 2 Also shown is an embodiment in which the width of the one-dimensional phononic crystal 17 is smaller than the width of the supporting beam 15 in which it is located.

[0065] It should be noted that when the one-dimensional phononic crystal 17 is in a one-dimensional state, it specifically means that each phonon unit cell 18 in the one-dimensional phononic crystal 17 is in a one-dimensional state. When the phonon unit cell 18 is in a one-dimensional state, the shape of the phonon unit cell 18 may include a cross shape. Of course, the phonon unit cell 18 can also adopt other shapes. The shape of the phonon unit cell 18 can be selected according to needs and will not be listed one by one here.

[0066] When the phononic unit cell 18 is cross-shaped, each phononic unit cell 18 may include a cross-shaped phononic unit cell plate and a unit cell scatterer penetrating the phononic crystal plate. Figure 3 and Figure 4 An embodiment in which the phonon unit cell 18 is cross-shaped is shown. The shape of the phonon unit cell 18 can be determined by the phonon unit cell plate. When the one-dimensional phononic crystal 17 is prepared in the corresponding support beam 15, it is connected to the side wall of the support beam 15 through the phonon unit cell plate, and adjacent phonon unit cells 18 are also connected into one through the corresponding phonon unit cell plate.

[0067] In one embodiment of the present invention, the phononic unit cell plate includes four unit cell fins 20 that are evenly and symmetrically distributed, wherein:

[0068] The phonon unit cell 18 is fixedly connected to the support beam 15 via a unit cell fin 20 , and is also connected to the unit cell fin 20 of the adjacent phonon unit cell 18 via the corresponding unit cell fin 20 ;

[0069] The unit cell scatterer includes a unit cell scattering main hole 19 located in the center of the phonon unit cell plate and unit cell scattering auxiliary holes 21 uniformly and symmetrically distributed on the outer circle of the unit cell scattering main hole 19.

[0070] Each unit cell scattering auxiliary hole 21 is distributed in the corresponding unit cell wing 20, and the unit cell scattering auxiliary holes 21 are connected to the unit cell scattering main hole 19;

[0071] The aperture of the unit cell scattering main hole 19 is larger than the aperture of the unit cell scattering auxiliary hole 21 .

[0072] Figure 3 and Figure 4 FIG1 shows an embodiment in which the phononic unit cell 18 is in a cross shape. As can be seen from the figure, the phononic unit cell plate includes four evenly distributed unit cell fins 20. Generally, the four unit cell fins 20 can be exactly the same. A cross-shaped phononic unit cell plate can be formed by using four evenly distributed unit cell fins 20. When the phononic unit cell 18 is connected to the support beam 15 and the adjacent phononic unit cell 18, it specifically refers to connecting the unit cell fins 20 to the support beam 15 and the adjacent phononic unit cell 18 through one unit cell fin 20. Figure 3 shown.

[0073] During specific implementation, the support beam 15 is generally in the shape of a straight block. Therefore, the arrangement direction of the phonon unit cells 18 prepared in the support beam 15 is also in a straight line. At this time, the one-dimensional phononic crystal 17 includes phonon unit cells 18 located at the end and phonon unit cells 18 located at the non-end. Among them, the phonon unit cells 18 located at the non-end are also the phonon unit cells 18 arranged in the middle position. For the phonon unit cells 18 located at the non-end, the unit cell fins 20 connected to the support beam 15 are used as support connecting fins, and the unit cell fins 20 connected to the unit cell fins 20 of the adjacent phonon unit cells 18 are used as unit cell connecting fins. At this time, the unit cell connecting fins and the support connecting fins are perpendicular to each other.

[0074] As shown in Figure 3, for the phononic unit cell 18 located at a non-end portion, a unit cell wing 20 in the phononic unit cell 18 forms a supporting connecting wing. At the same time, two corresponding unit cell wing pieces 20 in the phononic unit cell 18 serve as unit cell connecting wing pieces. In addition, there is a unit cell wing piece 20 in a suspended state, and the unit cell wing piece 20 in the suspended state corresponds to the supporting connecting wing piece. When the phononic unit cell 18 is located at the end portion of the one-dimensional phononic crystal 17, a unit cell wing piece 20 in the phononic unit cell 18 is in a suspended state, a unit cell wing piece 29 forms a unit cell connecting wing piece, and two unit cell wing pieces 20 form supporting connecting wing pieces. At this time, the two unit cell wing pieces 20 forming the supporting connecting wing pieces are perpendicular to each other, specifically so as to satisfy the connection between the phononic unit cell 18 and the adjacent phononic unit cell 18 and the support beam 15 in which the phononic unit cell 18 is located.

[0075] Figure 4An embodiment of the unit cell scatterer of the present invention is shown in the figure. As can be seen from the figure, the unit cell scatterer includes a unit cell scattering main hole 19 and unit cell scattering auxiliary holes 21 uniformly and symmetrically distributed on the outer circle of the unit cell scattering main hole 19. As can be seen from the above description, the unit cell scattering main hole 19 and the unit cell scattering auxiliary holes 21 all pass through the phonon unit cell plate, wherein the unit cell scattering main hole 19 is located at the center of the phonon unit cell plate, that is, the center of the unit cell scattering main hole 19 is concentric with the center of the phonon unit cell plate, and the unit cell scattering auxiliary holes 21 are distributed in a unit cell wing 20. Therefore, there are four unit cell scattering auxiliary holes 21 in the outer circle of the unit cell scattering main hole 19, and the unit cell scattering auxiliary holes 21 are connected to the unit cell scattering main hole 19 through the scattering transition hole 22, as shown in FIG. Figure 4 shown.

[0076] In one embodiment of the present invention, the unit cell scattering main hole 19 and the unit cell scattering auxiliary hole 21 are both circular holes, and the scattering transition hole 22 can be a rectangular hole. The aperture of the unit cell scattering main hole 19 is larger than the aperture of the unit cell scattering auxiliary hole 21. For the unit cell scattering auxiliary holes 21 corresponding to the two sides of the unit cell scattering main hole 19, the center of the unit cell scattering auxiliary hole 21 is collinear with the corresponding center of the unit cell scattering main hole 19.

[0077] It should be noted that when the phononic unit cell 18 of the present invention adopts the above-mentioned structural form, the one-dimensional phononic crystal 17 can have the required acoustic band gap. As can be seen from the following description, within the frequency range of 10 MHz to 13.31 MHz, the one-dimensional phononic crystal 17 of the present invention has a complete acoustic band gap, thereby effectively blocking and reflecting the sound waves leaked from the support beam 15; in addition, when the current one-dimensional phononic crystal 17 is adopted, the phononic crystal preparation process can be simplified and the processing cost of the resonator can be reduced.

[0078] In one embodiment of the present invention, the resonant substrate comprises at least an SOI substrate, wherein:

[0079] When the resonant substrate is an SOI substrate, a resonant separation groove 14 is etched in the resonant substrate, and the bottom silicon 3 in the resonant substrate is exposed through the groove bottom of the resonant separation groove 14. The resonant separation groove 14 is used to divide the SOI substrate into at least a resonant support region located in the resonant separation groove 14, a lead connection region located outside the resonant separation groove 14, and a support beam region for forming a support beam 15.

[0080] The resonator 7 is prepared on the functional silicon layer 1 in the resonance support area, and the support beam 15 is formed by the functional silicon layer 1 in the support beam area, and the functional silicon layer 1 in the support beam 15 is connected to the functional silicon layer 1 in the resonance support area.

[0081] From the above description, it can be seen that the resonant substrate can be an SOI substrate, and the SOI substrate used is consistent with the existing technology. Therefore, the resonant substrate may include an underlying silicon 3, a silicon dioxide layer 2 located on the underlying silicon 3, and a functional silicon layer 1 located on the silicon dioxide layer 2. The situation of forming the SOI substrate by the underlying silicon 3, the silicon dioxide layer 2 and the functional silicon layer 1 can be consistent with the existing technology. At this time, the front side of the resonant substrate can be formed by the functional silicon layer, and the corresponding back side of the resonant substrate can be formed by the underlying silicon 3. The resonator body and the phononic crystal unit of the present invention are both prepared on the front side of the resonant substrate.

[0082] In order to prepare the above-mentioned resonator body and phononic crystal unit, the front surface of the resonant substrate can be etched to form a resonant separation groove 14. Figure 1 and Figure 2 , an embodiment of etching the front side of the resonant substrate and forming a resonant separation groove 14 on the front side of the resonant substrate is shown. Specifically, when etching to form the resonant separation groove 14, the etching depth is at least the thickness of the functional silicon layer 1 and the silicon dioxide layer 2, that is, the bottom of the resonant separation groove 14 is the underlying silicon 3. At this time, the underlying silicon 3 corresponding to the resonant separation groove 14 can be exposed through the resonant separation groove 14.

[0083] like Figure 1 and Figure 2 As shown, the resonance separation groove 14 formed by etching may be rectangular, and the resonance separation groove 14 may include two corresponding sub-grooves, which are isolated by a support beam 15 and a resonator 7. The resonance support area is located in the central area of ​​the resonance separation groove 14. It should be understood that the resonance support area includes a complete SOI substrate structure, and a support island 12 can be formed by the functional silicon layer 1 in the resonance support area, and the resonator 7 is prepared on the support island 12. When the resonator 7 is prepared on the support island 12, it specifically means that the resonator 7 is prepared on the functional silicon layer 1 of the support island 12. In a specific implementation, the silicon dioxide layer 2 directly below the support island 12 is sacrificially released, so that the resonator 7 is suspended above the underlying silicon 3.

[0084] To form support beams 15, when etching the front surface of the resonant substrate, the etched area should not include the support beam region. This means that the support beam region also includes the complete SOI substrate structure. In this case, support beams 15 can be formed by the functional silicon layer 1 within the support beam region. In specific implementations, support beams 15 are interconnected with support islands 12. This means that the functional silicon layer 1 forming support beams 15 is correspondingly connected to the functional silicon layer 1 forming support islands 12. In this case, support beams 15 are also suspended.

[0085] In specific implementations, the portion outside the resonant separation groove 14 serves as the lead-out connection region. As can be seen from the above description, the lead-out connection region also includes the structure of the complete SOI substrate. It should be noted that the front surface of the resonant substrate can be etched using commonly used techniques in the art. The specific etching method and process conditions can be selected as needed to form the resonant separation groove 14 and the aforementioned resonant support region, lead-out connection region, and support beam region. When etching the resonant substrate, ensure that the support beam 15 is connected to the lead-out connection region. This will not affect the connection of the resonant lead-out electrode 8 to the lead-out connection region.

[0086] In the prior art, the energy of the resonator mainly leaks to the resonant substrate through the support beam 15. Therefore, the width and length of the support beam 15 will affect the quality factor Q of the resonator. In one embodiment of the present invention, in order to minimize the substrate impedance, the length of the support beam 15 is set to n*λ / 4, where n is an odd number and λ is the wavelength of the resonant sound wave when the resonator 7 is working.

[0087] As can be seen from the above description, the length of the support beam 15 specifically refers to the length between the support island 12 and the lead-out connection area. Figure 1 and Figure 2 In specific implementation, the length of the support beam 15 can be set according to the operating frequency of the resonator 7, thereby determining the condition parameters for etching the front surface of the resonant substrate, specifically based on forming the required support beam 15.

[0088] In one embodiment of the present invention, when preparing a one-dimensional phononic crystal 17 in a support beam 15, the functional silicon layer 1 in the support beam 15 is patterned to form a plurality of sequentially arranged phononic unit cells 18 after patterning. Thereafter, the unit cell scatterers in the phononic unit cell 18 are used to sacrificially release the silicon dioxide layer 2 corresponding to the unit cell scatterers, and after the sacrificial release of the silicon dioxide layer 2, a hollow unit cell scatterer is formed.

[0089] As can be seen from the above description, the one-dimensional phononic crystal 17 is prepared in the corresponding support beam 15. When preparing the one-dimensional phononic crystal 17, it is necessary to first pattern the functional silicon layer 1 in the support beam 15 so that a plurality of sequentially arranged phononic unit cells 18 can be formed after patterning. The formation of the phononic unit cells 18 can refer to the corresponding description above and will not be repeated here. In specific implementation, the functional silicon layer 1 in the support beam 15 can be etched using commonly used technical means in this technical field, that is, the functional silicon layer 1 can be patterned through an etching process.

[0090] Generally, when the functional silicon layer 1 within the support beam 15 is patterned using an etching process, the silicon dioxide layer 2 generally serves as a process stop layer. Subsequently, a sacrificial release process commonly used in the art can be used to sacrificially release the silicon dioxide layer 2 corresponding to the unit cell scatterer. After sacrificial release of the silicon dioxide layer 2, a hollowed-out unit cell scatterer is formed. Therefore, the hollowed-out state here specifically refers to a gap between the formed phonon unit cell 18 and the underlying silicon substrate 3. In specific implementations, when sacrificially releasing the silicon dioxide layer 2, the silicon dioxide layer 2 corresponding to the support island 12 can also be sacrificially released.

[0091] In addition, it can be seen from the above description that when the functional silicon layer 1 in the support beam 15 is patterned by etching or other methods, the length of the one-dimensional phononic crystal 17 formed should be smaller than the length of the support beam 15, and the width of the one-dimensional phononic crystal 17 should also be smaller than the width of the support beam 15.

[0092] In a specific implementation, the radius of the unit cell scattering primary aperture 19 can be 11-13 μm, and the radius of the unit cell scattering secondary aperture 21 can be 4-6.5 μm. The lattice constant of the phononic unit cell 18 can be fixed at 70 μm, and the thickness of the phononic unit cell plate within the phononic unit cell 18 can be 2 μm. As can be seen from the above description, the phononic unit cell plate is formed by the functional silicon layer 1. When the phononic unit cell 18 is configured with the current parameters, the one-dimensional phononic crystal 17 can have a complete acoustic band gap.

[0093] In one embodiment of the present invention, an in-plane acoustic reflection unit is further provided on the resonant substrate, wherein:

[0094] The in-plane acoustic reflection unit comprises at least two in-plane acoustic reflection grooves 16 etched and prepared in the resonant substrate, wherein:

[0095] The in-plane acoustic reflection grooves 16 correspond one to one with the support beams 15 , and the in-plane acoustic reflection grooves 16 are located outside the corresponding support beams 15 ;

[0096] The shape of the in-plane acoustic reflection groove 16 is similar to the shape of the sound wave before propagating through the resonator 7 to the air interface, so that the sound wave returns to the resonator 7 in the same phase after being reflected by the in-plane acoustic reflection groove 16 .

[0097] In order to further reduce the anchor loss and improve the quality factor Q of the resonator, an in-plane acoustic reflection unit can be set on the resonant substrate. Figure 1 and Figure 2FIG1 shows an embodiment of providing an in-plane acoustic reflection unit. As can be seen from the figure, the in-plane acoustic reflection unit may include two in-plane acoustic reflection grooves 16. When the in-plane acoustic reflection unit includes two in-plane acoustic reflection grooves 16, the in-plane acoustic reflection grooves 16 correspond to the support beams 15 in a one-to-one manner, and each in-plane acoustic reflection groove 16 is located on the outer side of the corresponding support beam 15. Figure 1 and Figure 2 In the embodiment, the in-plane acoustic reflection groove 16 is provided in the lead-out connection area.

[0098] In specific implementation, the in-plane acoustic reflection groove 16 can provide an additional air interface for the sound waves leaked through the support beam 15. The acoustic impedance of the air interface is approximately zero, so that when the sound waves propagate to the air interface, the sound waves can be reflected back into the resonator 7. That is, the in-plane acoustic reflection groove 16 and the corresponding support beam 15 can provide an impedance adaptation interface, and the provided impedance adaptation interface can be used to further realize the reflection of the leaked sound waves.

[0099] In one embodiment of the present invention, the shape of the in-plane acoustic reflection groove 16 is similar to the shape of the sound wave before it propagates through the resonator 7 to the air interface, so that the sound wave returns to the resonator 7 in the same phase after being reflected by the in-plane acoustic reflection groove 16; it can be understood that when the sound wave is reflected and returned to the resonator 7 in the same phase, the main modal capability can be further improved, thereby further reducing the anchor loss, thereby improving the quality factor Q of the resonator.

[0100] In one embodiment of the present invention, the in-plane acoustic reflection groove 16 is in an arc shape, wherein:

[0101] When the shape of the in-plane acoustic reflection groove 16 is arc-shaped, the arc-shaped openings of the in-plane acoustic reflection groove 16 all point to the resonator 7, and when the support beam 15 is projected onto the corresponding in-plane acoustic reflection groove 16, the projection of the support beam 15 is located in the in-plane acoustic reflection groove 16.

[0102] Figure 1 and Figure 2 An embodiment in which the in-plane acoustic reflection groove 16 is in the shape of an arc is shown. When the in-plane acoustic reflection groove 16 is an arc-shaped groove, the shape of the in-plane acoustic reflection groove 16 can be made similar to the shape of the sound wave before propagating through the resonator 7 to the air interface. The arc-shaped opening of the in-plane acoustic reflection groove 16 points to the resonator 7, and the width of the in-plane acoustic reflection groove 16 should be set to be larger than the width of the support beam 15, so that when the support beam 15 is projected onto the corresponding in-plane acoustic reflection groove 16, the projection of the support beam 15 is located within the in-plane acoustic reflection groove 16. In a specific implementation, the distance between the in-plane acoustic reflection groove 16 and the support beam anchor point can be 170μm, wherein the support beam anchor point specifically refers to the junction of the support beam 15 and the lead-out connection area.

[0103] When preparing the above-mentioned in-plane acoustic reflection groove 16, the functional silicon layer 1 in the lead-out connection area can be etched, wherein the etching depth is consistent with the thickness of the functional silicon layer 1. After the functional silicon layer 1 is etched, the silicon dioxide layer 2 in the etched area is sacrificially released using a silicon dioxide sacrificial release process, so that the in-plane acoustic reflection groove 16 can be formed after the sacrificial release.

[0104] In one embodiment of the present invention, the resonator 7 includes a resonant bottom electrode disposed on a resonant substrate, a resonant piezoelectric layer 12 disposed on the resonant bottom electrode, and a resonant top electrode disposed on the resonant piezoelectric layer 12, wherein:

[0105] The resonant top electrode includes a current collecting unit and an interdigital electrode unit adapted to be connected to the current collecting unit, wherein:

[0106] The busbar unit includes two resonant busbars 9,

[0107] The interdigital electrode unit includes interdigital electrodes electrically connected to the corresponding resonant bus bar 9, and each interdigital electrode is configured to have a main mode excitation enhancement state, wherein,

[0108] Based on the main modal excitation enhancement state of each interdigital electrode, the parasitic charges generated by connecting the interdigital electrode to the resonant bus bar 9 are concentrated in the central area of ​​the current interdigital electrode.

[0109] Specifically, the resonant body 7 is disposed on the resonant substrate, specifically, the resonant body 7 is disposed on the supporting island 12. The resonant body 7 may include a resonant bottom electrode, a resonant piezoelectric layer 12, and a resonant top electrode, wherein the resonant bottom electrode may be disposed on the functional silicon layer 1 of the supporting island 12, and the resonant bottom electrode may be made of an existing commonly used metal material, such as metal molybdenum. The resonant bottom electrode may be prepared on the functional silicon layer 1 using commonly used technical means in the art, and the resonant bottom electrode covers the functional silicon layer 1.

[0110] A resonant piezoelectric layer 12 is provided on the resonant bottom electrode. The resonant piezoelectric layer 12 can be made of commonly used materials, such as aluminum nitride. The resonant piezoelectric layer 12 covers the resonant bottom electrode. Figure 1 and Figure 2 Only the resonant piezoelectric layer 12 is shown in the figure, and the resonant bottom electrode is not shown. The resonant top electrode is arranged on the resonant piezoelectric layer 12, and the resonant top electrode is insulated and isolated from the resonant bottom electrode by the resonant piezoelectric layer 12.

[0111] In one embodiment of the present invention, the resonant top electrode should include a busbar unit and an interdigital electrode unit. Figure 1 and Figure 2FIG shows an embodiment in which the busbar unit includes two resonant busbars 9, the two resonant busbars 9 are parallel to each other, and the length direction of the resonant busbar 9 is perpendicular to the length direction of the support beam 15. In addition, Figure 1 and Figure 2 , an embodiment of an interdigital electrode unit is also shown. In the figure, the interdigital electrode unit includes three interdigital electrodes, which are located between two resonant bus bars 9. The two interdigital electrodes are electrically connected to the lower resonant bus bar 9 in the figure, and the middle interdigital electrode is electrically connected to the upper resonant bus bar 9 in the figure, forming an interdigitated state. Generally, the middle interdigital electrode can be coaxially distributed with the support beam 15.

[0112] It should be noted that when the interdigital electrodes are electrically connected to the corresponding resonant bus bar 9, when the interdigital electrodes use traditional rectangular electrodes, the interdigital electrodes are close to the two ends of the resonant bus bar 9, and parasitic charges are easily generated between the interdigital electrodes and the bus bar 9 due to the tip effect of the charge, thereby increasing the occurrence of stray modes. In order to effectively reduce stray modes, the present invention configures each interdigital electrode to have a state of enhanced main mode excitation. Specifically, based on the enhanced main mode excitation state of each interdigital electrode, the parasitic charges formed by the connection between the interdigital electrodes and the corresponding connected resonant bus bar 9 can be configured to be concentrated in the central area of ​​the current interdigital electrode. At this time, the excitation of the Lame mode can be enhanced, and the charge of the Lame mode should be mainly concentrated in the central area of ​​the resonant body 7, thereby reducing stray modes.

[0113] In one embodiment of the present invention, configuring the interdigital electrodes to have a main modal excitation enhancement state at least includes configuring the widths of both ends of the interdigital electrodes to be smaller than the width of the middle position of the interdigital electrodes.

[0114] Figure 1 and Figure 2 , an embodiment of configuring the interdigitated electrode to have a main modal excitation enhancement state is shown in the figure. As can be seen from the figure, the interdigitated electrode is divided into three parts: the interdigitated electrode connecting end 10, the interdigitated electrode middle part 6 and the interdigitated electrode non-connecting end 11, wherein the interdigitated electrode connecting end 10 is electrically connected to the corresponding resonant bus bar 9, the interdigitated electrode non-connecting end 11 is close to another resonant bus bar 9, and the interdigitated electrode connecting end 10 and the interdigitated electrode non-connecting end 11 are respectively located at the two ends of the interdigitated electrode middle part 6, and the corresponding widths of the interdigitated electrode connecting end 10 and the interdigitated electrode non-connecting end 11 are smaller than the width of the interdigitated electrode middle part 6, so that the corresponding interdigitated electrode can be configured to have a main modal excitation enhancement state.

[0115] In a specific implementation, the width of the middle portion 6 of the interdigital electrode can be 160 μm to 320 μm, the corresponding widths of the interdigital electrode connecting end 10 and the interdigital electrode non-connecting end 11 can be 80 μm to 160 μm, and the length of each interdigital electrode can be 1600 μm. Of course, the width and length of the interdigital electrode can also be set to other values, which can be selected according to needs and will not be given as examples here.

[0116] As can be seen from the above description, the resonant bus bar 9 in the bus unit and the interdigital electrodes of the interdigital electrode unit can be formed by the top electrode layer provided on the resonant piezoelectric layer 12. Specifically, after the top electrode layer is provided on the resonant piezoelectric layer 12, the etching process commonly used in the art can be used to etch and form the corresponding bus unit and interdigital electrode unit. The conditions of the formed bus unit and interdigital electrode unit can be referred to. Figure 1 、 Figure 2 As described above, I will not repeat them here.

[0117] Specifically, after the interdigital electrodes in the interdigital electrode unit are electrically connected to the corresponding resonant bus bar 9, one resonant bus bar 9 and the corresponding electrically connected interdigital electrodes can be configured as the resonant input electrode of the resonator 7, and the other resonant bus bar 9 and the corresponding electrically connected interdigital electrodes can be configured as the resonant output electrode of the resonator 7. Figure 1 The resonant bus bar 9 in the upper region and the corresponding electrically connected interdigitated electrodes are configured as resonant input electrodes. Figure 1 The resonant bus bar 9 in the lower region and the corresponding electrically connected interdigitated electrodes are configured as resonant output electrodes.

[0118] After forming the resonant input electrode and the resonant output electrode, a resonant extraction electrode 8 should be provided to facilitate the control of the resonant body 7. In one embodiment of the present invention, two resonant extraction electrodes 8 should be provided, so that the resonant input electrode can be extracted by one resonant extraction electrode 8, and the resonant output electrode can be extracted by the other resonant extraction electrode 8. Figure 1 and Figure 2 FIG. 3 shows an embodiment of using two resonance extraction electrodes to connect the resonance input electrode and the resonance output electrode respectively.

[0119] Specifically, the resonant extraction electrode 8 can adopt the same structural form as the resonant body 7. In this case, the resonant extraction electrode 8 can include an extraction bottom electrode, an extraction piezoelectric layer, and an extraction top electrode. The extraction bottom electrode can be prepared using the same process steps as the resonant bottom electrode. Similarly, the extraction piezoelectric layer can be prepared using the same process steps as the resonant piezoelectric layer 12. The extraction top electrode can be prepared using the same process steps as the above-mentioned resonant top electrode. For example, a bottom electrode layer, a piezoelectric film, and a top electrode layer are sequentially prepared on the functional silicon layer 1. Thereafter, when etching is used to form a resonant separation groove, the resonant bottom electrode, the resonant piezoelectric layer, and the resonant top electrode of the resonant body 7 can be formed, and the extraction bottom electrode, the extraction piezoelectric layer, and the extraction top electrode in the resonant extraction electrode 8 can be formed at the same time. Unlike the above-mentioned resonant top electrode, the extraction top electrode can be a whole.

[0120] In one embodiment of the present invention, the resonant extraction electrode 8 may include a first extraction portion located on the support beam 15 and a second extraction portion located on the extraction connection area. Figure 1 and Figure 2 The figure shows an embodiment in which the resonant extraction electrode 8 is L-shaped. As can be seen from the above description, the first extraction portion is supported on the functional silicon layer 1 within the support beam 15, and the second extraction portion is supported on the functional silicon layer 1 in the extraction connection area. In specific implementations, the resonant extraction electrode 8 should be insulated and isolated from both the support beam 15 and the corresponding functional silicon layer 1 within the extraction connection layer.

[0121] In addition, an extraction electrode terminal 4 should be provided in the extraction connection region. The extraction electrode unit 4 should be electrically connected to the extraction top electrode. The extraction electrode terminal 4 should be relatively large in area to facilitate electrical connection between the extraction electrode terminal 4 and the corresponding resonant extraction electrode 8. The extraction bottom electrode within the resonant extraction electrode 8 should generally be grounded. Therefore, a grounding electrode terminal 5 should also be provided in the extraction connection region and electrically connected to the extraction bottom electrode. In a specific implementation, the extraction bottom electrode and the extraction piezoelectric layer within the extraction connection region can be extended to the region where the grounding electrode terminal 5 is located. Thereafter, the extraction piezoelectric layer is etched to expose the extraction bottom electrode and form the grounding electrode terminal 5.

[0122] As can be seen from the above description, the TPoS resonator of the present invention has the same working mechanism as the existing resonator, and both operate in the Lamb wave mode. In the Lamb wave mode excitation mode, positive and negative voltages are generally applied alternately to the resonant input electrode. At this time, the electric fields formed by the two adjacent interdigital electrodes and the resonant bottom electrode are in opposite directions. Due to the inverse piezoelectric effect, strains are generated in the X and Z directions. According to the characteristics of the piezoelectric material, the strains in the X and Z directions generate electrical signals through the direct piezoelectric effect. When the frequency of the input signal is the same as the designed operating frequency of the TPoS resonator, resonance will occur. At this time, the output signal from the resonant output electrode is the largest. Specifically, the X direction refers to the width direction of the resonant body 7, the direction from the resonant input electrode to the resonant output electrode can form the Y direction, and the Z direction can generally be the thickness direction of the resonant substrate.

[0123] It should be noted that when the TPoS resonator of the present invention operates in the Lamb wave mode, the main modal energy in the present invention specifically refers to the energy of the resonator 7 caused by the propagation of the Lamb wave in the resonator 7 to cause the resonator 7 to vibrate.

[0124] In one embodiment of the present invention, when the one-dimensional phononic crystal 17 is formed by sequentially connecting a plurality of phononic unit cells 18, the band gap characteristics of the one-dimensional phononic crystal 17 can be used to reflect the acoustic waves leaked from the support beam 15. In a specific implementation, by scanning the wave vector k of the first irreducible Brillouin zone of the one-dimensional phononic crystal 17, the following is obtained: Figure 5 The acoustic band gap diagram shown in the figure shows that in the frequency range of 10MHz to 13.31MHz, the one-dimensional phononic crystal 17 has a complete acoustic band gap. When the operating frequency of the TPoS resonator is within the complete acoustic band gap of the one-dimensional phononic crystal 17, the sound waves leaked from the support beam 15 can be best suppressed, thereby effectively reducing the anchor point loss and significantly improving the quality factor Q of the TPoS resonator.

[0125] In order to characterize the improvement effect of the present invention on the quality factor Q of the TPoS resonator, Figure 6 FIG. 1 is a schematic diagram showing a comparison of the corresponding admittance diagrams of the TPoS resonator of the present invention and the existing TPoS resonator. Figure 6 In the figure, the horizontal axis is frequency and the vertical axis is admittance. In the figure, the curve where the dots are located represents the admittance of the TPoS resonator of the present invention, and the curve where the diamonds are located represents the admittance of the existing TPoS resonator. Among them, the existing TPoS resonator specifically refers to a resonator in which the one-dimensional phononic crystal 17 is not prepared in the support beam 15 and the in-plane acoustic reflection groove 16 is not set.

[0126] Depend on Figure 6It can be seen that, under the condition of ensuring that the resonant frequency and electromechanical coupling coefficient of the TPoS resonator remain basically unchanged, by utilizing the one-dimensional phononic crystal 17, the in-plane acoustic reflection groove 16, and the interdigital electrodes, the motion impedance and the influence of stray modes of the TPoS resonator provided by the present invention are significantly reduced, the main mode is enhanced, and the quality factor Q value is significantly improved. Specifically, compared with the existing TPoS resonator, the quality factor Q value of the TPoS resonator of the present invention is improved by 3 to 5 times, and the interdigital electrodes can effectively reduce stray modes and enhance the excitation of Lame modes.

[0127] The above description is merely a selection of preferred embodiments of the present invention and is not intended to limit the present invention. Those skilled in the art will appreciate that, within the scope of the technical solution provided by the present invention, numerous possible modifications to the technical solution of the present invention can be made using the methods and technical content described above. Therefore, any simple, similar, or equivalent variations, modifications, and substitutions made to the above embodiments that do not depart from the technical solution of the present invention shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. A TPoS resonator with low anchor loss and high quality factor, characterized by: The TPoS resonator includes: The resonator body includes a resonant substrate, a resonant body prepared on the resonant substrate, and a support beam unit for supporting a resonant extraction electrode, wherein: The support beam unit includes at least two support beams distributed on both sides of the resonator, and each support beam supports a resonant extraction electrode adapted to be electrically connected to the resonator; The phononic crystal unit includes at least one one-dimensional phononic crystal for forming an acoustic reflection region, wherein: A one-dimensional phononic crystal is prepared in a support beam, and the operating frequency of the resonator is located within the acoustic band gap formed by the one-dimensional phononic crystal; The one-dimensional phononic crystal includes a plurality of phononic unit cells connected in sequence, and the arrangement direction of the phononic unit cells in the one-dimensional phononic crystal is consistent with the direction of the support beam pointing to the resonator.

2. The TPoS resonator with low anchor loss and high quality factor according to claim 1 is characterized in that: A one-dimensional phononic crystal is prepared in each support beam, and the arrangement length of the phononic unit cells in the one-dimensional phononic crystal is no longer than the length of the support beam; The shapes of the phonon unit cell include a cross, where When the shape of the phonon unit cell is a cross, the phonon unit cell includes a cross-shaped phonon unit cell plate and a unit cell scatterer that penetrates the phonon crystal plate and is in a hollow state. The phonon unit cell is connected to the supporting beam via the phonon unit cell plate, and adjacent phonon unit cells are connected into one piece via corresponding phonon unit cell plates.

3. The TPoS resonator with low anchor loss and high quality factor according to claim 2, characterized in that: The phononic unit cell plate includes four unit cell wings that are evenly and symmetrically distributed, wherein: The phonon unit cell is fixedly connected to the support beam via a unit cell wing, and is connected to the unit cell wing of the adjacent phonon unit cell via the corresponding unit cell wing; The unit cell scatterer includes a unit cell scattering main hole located in the central area of ​​the phonon unit cell plate and unit cell scattering auxiliary holes uniformly and symmetrically distributed on the outer circle of the unit cell scattering main hole. Each unit cell scattering auxiliary hole is distributed in the corresponding unit cell wing, and the unit cell scattering auxiliary holes are connected to the unit cell scattering main hole; The aperture of the unit cell scattering main hole is larger than the aperture of the unit cell scattering auxiliary hole.

4. The TPoS resonator with low anchor loss and high quality factor according to claim 1, characterized in that: It also includes an in-plane acoustic reflection unit arranged on the resonant substrate, wherein, The in-plane acoustic reflection unit comprises at least two in-plane acoustic reflection grooves etched and prepared in the resonant substrate, wherein: The in-plane acoustic reflection grooves correspond to the support beams one-to-one, and the in-plane acoustic reflection grooves are located outside the corresponding support beams; The shape of the in-plane acoustic reflection groove is similar to the shape of the sound wave before it propagates through the resonator to the air interface, so that the sound wave returns to the resonator in the same phase after being reflected by the in-plane acoustic reflection groove.

5. The TPoS resonator with low anchor loss and high quality factor according to claim 4, characterized in that: The shape of the in-plane acoustic reflection groove is arc-shaped, wherein, When the shape of the in-plane acoustic reflection groove is arc-shaped, the arc-shaped openings of the in-plane acoustic reflection groove all point to the resonator, and when the support beam is projected onto the corresponding in-plane acoustic reflection groove, the projection of the support beam is located in the in-plane acoustic reflection groove.

6. The TPoS resonator with low anchor loss and high quality factor according to claim 1, characterized in that: The resonator includes a resonant bottom electrode disposed on a resonant substrate, a resonant piezoelectric layer disposed on the resonant bottom electrode, and a resonant top electrode disposed on the resonant piezoelectric layer, wherein: The resonant top electrode includes a current collecting unit and an interdigital electrode unit adapted to be connected to the current collecting unit, wherein: The busbar unit includes two resonant busbars. The interdigital electrode unit includes interdigital electrodes electrically connected to corresponding resonant bus bars, and each interdigital electrode is configured to have a main mode excitation enhancement state, wherein, Based on the main mode excitation enhancement state of each interdigital electrode, the parasitic charges generated by connecting the interdigital electrodes to the resonant bus bar are concentrated in the central area of ​​the current interdigital electrodes.

7. The TPoS resonator with low anchor loss and high quality factor according to claim 6, characterized in that: Configuring the interdigital electrodes to have a main modal excitation enhancement state at least includes configuring the widths at both ends of the interdigital electrodes to be smaller than the width at the middle of the interdigital electrodes.

8. The TPoS resonator with low anchor loss and high quality factor according to any one of claims 2 to 7, characterized in that: The resonant substrate at least includes an SOI substrate, wherein: When the resonant substrate is an SOI substrate, a resonant separation groove is etched in the resonant substrate, and the bottom silicon of the resonant substrate is exposed through the groove bottom of the resonant separation groove, so that the SOI substrate is divided into at least a resonant support region located within the resonant separation groove, a lead connection region located outside the resonant separation groove, and a support beam region for forming a support beam by using the resonant separation groove; The resonator is prepared on the functional silicon layer in the resonance support area, and the support beam is formed by the functional silicon layer in the support beam area, and the functional silicon layer in the support beam is connected to the functional silicon layer in the resonance support area.

9. The TPoS resonator with low anchor loss and high quality factor according to claim 8, characterized in that: When preparing a one-dimensional phononic crystal in a support beam, the functional silicon layer in the support beam is patterned to form a number of phononic crystal cells arranged in sequence after patterning. Thereafter, the crystal cell scatterers in the phononic crystal cell are used to sacrificially release the silicon dioxide layer corresponding to the crystal cell scatterers, and after the sacrificial release of the silicon dioxide layer, a hollow crystal cell scatterer is formed.

10. The TPoS resonator with low anchor loss and high quality factor according to claim 8, characterized in that: The length of the support beam is n*λ / 4, where n is an odd number and λ is the wavelength of the resonant sound wave when the resonator is working.

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