Bulk acoustic wave resonator device and formation method, filtering device and radio frequency front-end device

Abstract

A bulk acoustic wave resonator device and formation method, a filtering device and a radio frequency front-end device, wherein the bulk acoustic wave resonator device includes: a first layer including a cavity; a first electrode layer; a piezoelectric layer, located on the first electrode layer, covering the cavity, including a first side and an opposite second side, the first electrode layer being located on the first side; a second electrode layer, located on the second side, located on the piezoelectric layer, and the overlapping portion of the second electrode layer with the first electrode layer is located above the cavity, corresponding to the cavity; a first composite structure, located on the first side, contacting the piezoelectric layer, and horizontally adjacent to the first electrode layer, the first end of the first composite structure close to the first electrode layer is located in the cavity, and the second end horizontally opposite to the first end of the first electrode layer is embedded in the first layer, including a first edge extension layer and a first support layer, the first support layer being located between the piezoelectric layer and the first edge extension layer, and being used to reduce edge capacitance, improve the electromechanical coupling coefficient, block leakage waves, and improve the Q value.

Description

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on September 8, 2021, with application number 2021110419331 and invention name “Bulk acoustic wave resonator device, filtering device and RF front-end device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present invention relates to the field of semiconductor technology, and in particular to a bulk acoustic wave resonator device and a forming method thereof, a filtering device, and a radio frequency front-end device. Background Art

[0003] The RF front-end chips for wireless communication devices include power amplifiers, antenna switches, RF filters, multiplexers, and low-noise amplifiers. RF filters include piezoelectric surface acoustic wave (SAW) filters, piezoelectric bulk acoustic wave (BAW) filters, micro-electro-mechanical system (MEMS) filters, and integrated passive device (IPD) filters.

[0004] SAW resonators and BAW resonators have high quality factors (Q values). RF filters made of SAW resonators and BAW resonators have low insertion loss and high out-of-band suppression. These filters are the mainstream RF filters currently used in wireless communication devices such as mobile phones and base stations. The Q value is the quality factor of the resonator, defined as the center frequency divided by the 3dB bandwidth of the resonator. The operating frequency of SAW filters is generally 0.4GHz to 2.7GHz, and the operating frequency of BAW filters is generally 0.7GHz to 7GHz.

[0005] Compared to SAW resonators, BAW resonators offer superior performance, but due to the complex manufacturing process, BAW resonators are more expensive to manufacture. However, as wireless communication technology evolves, more and more frequency bands are being used. Furthermore, with the application of frequency overlay technologies like carrier aggregation, mutual interference between wireless frequency bands is becoming increasingly severe. High-performance BAW technology can address this inter-band interference problem. With the advent of the 5G era, wireless mobile networks are introducing higher frequency bands, and currently, only BAW technology can address the filtering issues in these high-frequency bands.

[0006] Figure 1A BAW filter circuit 100 is shown, comprising a ladder circuit composed of a plurality of BAW resonators, wherein f1, f2, f3, and f4 represent four different frequencies, respectively. In each BAW resonator, the metal electrodes on both sides of the piezoelectric layer of the resonator generate alternating positive and negative voltages, and the piezoelectric layer generates acoustic waves through the alternating positive and negative voltages. The acoustic waves in the resonator propagate in a direction perpendicular to the piezoelectric layer. In order to form resonance, the acoustic wave needs to be totally reflected by the upper surface of the upper metal electrode and the lower surface of the lower metal electrode to form a standing acoustic wave. The condition for the reflection of the acoustic wave is that the acoustic impedance of the contact area with the upper surface of the upper metal electrode and the lower surface of the lower metal electrode is significantly different from the acoustic impedance of the metal electrodes.

[0007] A film bulk acoustic wave resonator (FBAR) is a BAW resonator that confines acoustic wave energy within the device. The resonator's resonant region is surrounded by air or vacuum above and a cavity below. The acoustic impedance of air and vacuum differs significantly from that of metal electrodes, allowing acoustic waves to be totally reflected by the upper and lower surfaces of the upper and lower metal electrodes, forming standing waves.

[0008] Figure 2 A schematic structural diagram of an FBAR 200 is shown. The FBAR 200 includes: a substrate 201 including a cavity 203; a first electrode layer 205 (i.e., a lower electrode layer) located on the substrate 201 and the cavity 203, covering the cavity 203; a piezoelectric layer 207 located on the substrate 201 and covering the first electrode layer 205, the piezoelectric layer 207 including a protrusion 207a located above the first electrode layer 205; and a second electrode layer 209 (i.e., an upper electrode layer) located on the piezoelectric layer 207, the second electrode layer 209 including a protrusion 209a located on the protrusion 207a. Fringe capacitance 213 exists between the first electrode layer 205 and the second electrode layer 209 outside the resonance region 211, causing acoustic energy loss, thereby reducing the electromechanical coupling factor and Q value of the resonator. Summary of the Invention

[0009] The problem solved by the present invention is to provide a bulk acoustic wave resonator device and a formation method, a filtering device and a radio frequency front-end device, which can reduce edge capacitance, improve the electromechanical coupling coefficient, block leakage waves, and improve the Q value.

[0010] To solve the above problems, an embodiment of the present invention provides a bulk acoustic wave resonator device, comprising: a first layer, the first layer including a cavity; a first electrode layer, at least one end of the first electrode layer being located in the cavity; a piezoelectric layer, located on the first electrode layer and covering the cavity, the piezoelectric layer including a first side and a second side opposite to the first side in a vertical direction, the first electrode layer being located on the first side; a second electrode layer, located on the second side and located on the piezoelectric layer, the overlapping portion of the second electrode layer with the first electrode layer being located above the cavity and corresponding to the cavity; and a first composite structure, located on the first side, contacting the piezoelectric layer, and horizontally adjacent to the first electrode layer, the first end of the first composite structure close to the first electrode layer being located in the cavity, and the second end of the first composite structure, horizontally opposite to the first end of the first electrode layer and away from the first end, being embedded in the first layer, the first composite structure comprising a first edge extension layer and a first support layer, the first support layer being located between the piezoelectric layer and the first edge extension layer for reducing edge capacitance.

[0011] In some embodiments, the material of the first edge extension layer includes metal; the medium of the first supporting layer includes one of the following: non-metallic material, air, and vacuum.

[0012] In some embodiments, it also includes: a first edge structure located on the first side, contacting the piezoelectric layer, the first edge structure including a third side and a fourth side horizontally opposite to the third side, the first electrode layer is located on the third side, and the first composite structure is located on the fourth side.

[0013] In some embodiments, the first edge structure includes a first edge surrounding layer, a material of the first edge surrounding layer includes metal, the first edge surrounding layer is connected to the first electrode layer, and the first edge surrounding layer is further connected to the first edge extension layer.

[0014] In some embodiments, the first composite structure and the second electrode layer have a second overlapping portion, and a width of the second overlapping portion is equal to a width of the first edge structure.

[0015] In some embodiments, the first composite structure further includes a first edge portion, the first edge portion including a fifth side and a sixth side horizontally opposite to the fifth side, the first electrode layer is located on the fifth side, and the first edge extension layer and the first support layer are located on the sixth side.

[0016] In some embodiments, the thickness of the first edge portion is equal to the sum of the thicknesses of the first edge extension layer and the first supporting layer.

[0017] In some embodiments, the first edge extension layer, the first support layer, and the second electrode layer have a fourth overlapping portion, and a width of the fourth overlapping portion is equal to a width of the first edge portion.

[0018] In some embodiments, the first layer includes: an intermediate layer, the intermediate layer includes the cavity, wherein a material of the intermediate layer includes at least one of the following: a polymer, an insulating dielectric, and polysilicon.

[0019] It should be noted that the first composite structure is electrically connected to the first electrode layer or the edge structure of the first electrode. The first composite structure includes a first edge extension layer and a first composite support layer. The first composite support layer thickens the dielectric thickness between the first edge extension layer and the second electrode layer, thereby reducing the edge capacitance, improving the electromechanical coupling coefficient, blocking leakage waves, and improving the Q value.

[0020] An embodiment of the present invention also provides a method for forming a bulk acoustic wave resonator device, comprising: forming a piezoelectric layer, the piezoelectric layer including a first side and a second side opposite to the first side in a direction perpendicular to the first side; forming a first electrode layer, located on the first side; forming a first layer, located on the first side, the first electrode layer located between the first layer and the piezoelectric layer and embedded in the first layer; forming a second electrode layer, located on the second side; forming a first composite structure, located on the first side, contacting the piezoelectric layer, and horizontally adjacent to the first electrode layer, the first composite structure having a second end horizontally opposite to the first end of the first electrode layer and away from the first composite structure and embedded in the first layer, the forming of the first composite structure comprising: forming a first edge extension layer and a first supporting layer, the first supporting layer being located between the piezoelectric layer and the first edge extension layer for reducing edge capacitance; and forming a cavity, located on the first side, the cavity being located between the first layer and the piezoelectric layer and embedded in the first layer, the piezoelectric layer covering the cavity, at least one end of the first electrode layer being located within the cavity, and the first end of the first composite structure close to the first electrode layer being located within the cavity.

[0021] In some embodiments, forming the first layer includes: forming a sacrificial layer on the first side of the piezoelectric layer, the sacrificial layer covering a portion of the first electrode layer, and the sacrificial layer covering at least one end of the first electrode layer; forming a first bonding layer on the first side of the piezoelectric layer, the first bonding layer covering the sacrificial layer and the first electrode layer; providing a substrate; forming a second bonding layer on one side of the substrate; bonding the first bonding layer and the second bonding layer to form an intermediate layer, the substrate is located on the first side, and the intermediate layer is located between the substrate and the piezoelectric layer.

[0022] In some embodiments, the method further includes: providing a transition substrate; and forming the piezoelectric layer based on the transition substrate, wherein the transition substrate is located on the second side.

[0023] In some embodiments, the method further includes: after forming the first layer, removing the transition substrate; and after removing the transition substrate, forming the second electrode layer.

[0024] In some embodiments, forming the cavity includes removing the sacrificial layer, wherein removing the sacrificial layer includes wet etching the sacrificial layer.

[0025] In some embodiments, it also includes: before forming the first composite structure, forming a first edge structure, located on the first side, contacting the piezoelectric layer, the first edge structure including a third side and a fourth side horizontally opposite to the third side, the first electrode layer is located on the third side, and the first composite structure is located on the fourth side.

[0026] In some embodiments, forming the first edge structure includes forming a first edge surrounding layer, wherein the material of the first edge surrounding layer includes metal, the first edge surrounding layer is connected to the first electrode layer, and the first edge surrounding layer is also connected to the first edge extension layer.

[0027] In some embodiments, the first composite structure and the second electrode layer have a second overlapping portion, and a width of the second overlapping portion is equal to a width of the first edge structure.

[0028] In some embodiments, forming the first composite structure also includes: forming a first edge portion, the first edge portion including a fifth side and a sixth side horizontally opposite to the fifth side, the first electrode layer is located on the fifth side, and the first edge extension layer and the first support layer are located on the sixth side.

[0029] In some embodiments, the thickness of the first edge portion is equal to the sum of the thicknesses of the first edge extension layer and the first supporting layer.

[0030] In some embodiments, the first edge extension layer, the first support layer, and the second electrode layer have a fourth overlapping portion, and a width of the fourth overlapping portion is equal to a width of the first edge portion.

[0031] An embodiment of the present invention also provides a bulk acoustic wave resonance device, comprising: a first layer, the first layer including a cavity; a first electrode layer, at least one end of the first electrode layer being located in the cavity; a piezoelectric layer, located on the first electrode layer, covering the cavity, the piezoelectric layer including a first side and a second side opposite to the first side in a vertical direction, the first electrode layer being located on the first side; a second electrode layer, located on the second side, located on the piezoelectric layer, the overlapping portion of the second electrode layer with the first electrode layer being located above the cavity, corresponding to the cavity; and a second composite structure, located on the second side, contacting the piezoelectric layer, and being adjacent to the second electrode layer in a horizontal direction, the second composite structure having no overlapping portion or partially overlapping with the first electrode layer, the second composite structure including a second edge extension layer and a second support layer, the second support layer being located between the piezoelectric layer and the second edge extension layer, for reducing edge capacitance.

[0032] In some embodiments, the material of the second edge extension layer includes metal; the medium of the second supporting layer includes one of the following: non-metallic material, air, and vacuum.

[0033] In some embodiments, it also includes: a second edge structure located on the second side, contacting the piezoelectric layer, the second edge structure including a third side and a fourth side horizontally opposite to the third side, the second electrode layer is located on the third side, and the second composite structure is located on the fourth side.

[0034] In some embodiments, the second edge structure includes a second edge surrounding layer, the material of the second edge surrounding layer includes metal, the second edge surrounding layer is connected to the second electrode layer, and the second edge surrounding layer is further connected to the second edge extension layer.

[0035] In some embodiments, the second composite structure and the first electrode layer have a second overlapping portion, and a width of the second overlapping portion is equal to a width of the second edge structure.

[0036] In some embodiments, the second composite structure further includes a second edge portion, the second edge portion including a fifth side and a sixth side horizontally opposite to the fifth side, the second electrode layer is located on the fifth side, and the second edge extension layer and the second support layer are located on the sixth side.

[0037] In some embodiments, the thickness of the second edge portion is equal to the sum of the thicknesses of the second edge extension layer and the second supporting layer.

[0038] In some embodiments, the second edge extension layer, the second supporting layer, and the first electrode layer have a fourth overlapping portion, and a width of the fourth overlapping portion is equal to a width of the second edge portion.

[0039] It should be noted that the second composite structure is electrically connected to the second electrode layer or the edge structure corresponding to the second electrode layer. The second composite structure includes a second edge extension layer and a second composite support layer. The second composite support layer thickens the dielectric thickness between the second edge extension layer and the first electrode layer, thereby reducing the edge capacitance, improving the electromechanical coupling coefficient, blocking leakage waves, and improving the Q value.

[0040] In some embodiments, the first layer includes: an intermediate layer, the intermediate layer includes the cavity, wherein a material of the intermediate layer includes at least one of the following: a polymer, an insulating dielectric, and polysilicon.

[0041] An embodiment of the present invention also provides a method for forming a bulk acoustic wave resonator device, including: forming a piezoelectric layer, the piezoelectric layer including a first side and a second side opposite to the first side in a vertical direction; forming a first electrode layer, located on the first side; forming a first layer, located on the first side, the first electrode layer being located between the first layer and the piezoelectric layer and embedded in the first layer; forming a second electrode layer, located on the second side; forming a second composite structure, located on the second side, contacting the piezoelectric layer, and being adjacent to the second electrode layer in a horizontal direction, the second composite structure having no overlapping portion or partially overlapping with the first electrode layer, forming the second composite structure including: forming a second edge extension layer and a second supporting layer, the second supporting layer being located between the piezoelectric layer and the second edge extension layer for reducing edge capacitance; and forming a cavity, located on the first side, the cavity being located between the first layer and the piezoelectric layer and embedded in the first layer, the piezoelectric layer covering the cavity, and at least one end of the first electrode layer being located in the cavity.

[0042] In some embodiments, forming the first layer includes: forming a sacrificial layer on the first side of the piezoelectric layer, the sacrificial layer covering a portion of the first electrode layer, and the sacrificial layer covering at least one end of the first electrode layer; forming a first bonding layer on the first side of the piezoelectric layer, the first bonding layer covering the sacrificial layer and the first electrode layer; providing a substrate; forming a second bonding layer on one side of the substrate; bonding the first bonding layer and the second bonding layer to form an intermediate layer, the substrate is located on the first side, and the intermediate layer is located between the substrate and the piezoelectric layer.

[0043] In some embodiments, the method further includes: providing a transition substrate; and forming the piezoelectric layer based on the transition substrate, wherein the transition substrate is located on the second side.

[0044] In some embodiments, the method further includes: after forming the first layer, removing the transition substrate; and after removing the transition substrate, forming the second electrode layer.

[0045] In some embodiments, forming the cavity includes removing the sacrificial layer, wherein removing the sacrificial layer includes wet etching the sacrificial layer.

[0046] In some embodiments, the method further includes: before forming the second composite structure, forming a second edge structure, located on the second side, contacting the piezoelectric layer, the second edge structure including a third side and a fourth side horizontally opposite to the third side, the second electrode layer being located on the third side, and the second composite structure being located on the fourth side.

[0047] In some embodiments, forming the second edge structure includes: forming a second edge surrounding layer, wherein the material of the second edge surrounding layer includes metal, the second edge surrounding layer is connected to the second electrode layer, and the second edge surrounding layer is further connected to the second edge extension layer.

[0048] In some embodiments, the second composite structure and the first electrode layer have a second overlapping portion, and a width of the second overlapping portion is equal to a width of the second edge structure.

[0049] In some embodiments, forming the second composite structure also includes: forming a second edge portion, the second edge portion including a fifth side and a sixth side horizontally opposite to the fifth side, the second electrode layer is located on the fifth side, and the second edge extension layer and the second support layer are located on the sixth side.

[0050] In some embodiments, the thickness of the second edge portion is equal to the sum of the thicknesses of the second edge extension layer and the second supporting layer.

[0051] In some embodiments, the second edge extension layer, the second supporting layer, and the first electrode layer have a fourth overlapping portion, and a width of the fourth overlapping portion is equal to a width of the second edge portion.

[0052] An embodiment of the present invention further provides a filtering device, including but not limited to: a bulk acoustic wave resonator device provided by at least one of the above embodiments.

[0053] An embodiment of the present invention further provides a radio frequency front-end device, including but not limited to: a power amplifier device and at least one filtering device provided by the above embodiment; the power amplifier device is connected to the filtering device.

[0054] An embodiment of the present invention further provides a radio frequency front-end device, including but not limited to: a low-noise amplifier and at least one filtering device provided by the above embodiment; the low-noise amplifier is connected to the filtering device.

[0055] An embodiment of the present invention further provides a radio frequency front-end device, including but not limited to: a multiplexing device, wherein the multiplexing device includes at least one filtering device provided by the above embodiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 is a schematic structural diagram of a BAW filter circuit 100;

[0057] Figure 2 It is a structural diagram of FBAR200;

[0058] Figures 3 to 6 1 is a schematic structural diagram of each step of a method for forming a bulk acoustic wave resonator device 300 according to an embodiment of the present invention;

[0059] Figure 7 is a schematic diagram of acoustic impedance of a bulk acoustic wave resonator 300 according to an embodiment of the present invention;

[0060] Figure 8 is a performance diagram of a bulk acoustic wave resonator device 300 according to an embodiment of the present invention;

[0061] Figure 9 It is a schematic diagram of the structure of hexagonal crystal grains;

[0062] Figure 10 (i) is a schematic diagram of the structure of an orthorhombic crystal grain;

[0063] Figure 10 (ii) is a schematic diagram of the structure of a tetragonal crystal grain;

[0064] Figure 10 (iii) is a schematic diagram of the structure of a cubic crystal grain;

[0065] Figures 11 to 14 1 is a schematic structural diagram of each step of a method for forming a bulk acoustic wave resonator device 400 according to an embodiment of the present invention;

[0066] Figures 15 to 18 1 is a schematic structural diagram of each step of a method for forming a bulk acoustic wave resonator 500 according to an embodiment of the present invention;

[0067] Figures 19 to 22 1 is a schematic structural diagram of each step of a method for forming a bulk acoustic wave resonator device 600 according to an embodiment of the present invention;

[0068] Figure 23 is a schematic diagram of acoustic impedance of a bulk acoustic wave resonator device 600 according to an embodiment of the present invention;

[0069] Figures 24 to 27 1 is a schematic structural diagram of each step of a method for forming a bulk acoustic wave resonator device 700 according to an embodiment of the present invention;

[0070] Figures 28 to 31 1 is a schematic structural diagram of each step of a method for forming a bulk acoustic wave resonator device 800 according to an embodiment of the present invention;

[0071] Figures 32 to 35 1 is a schematic structural diagram of each step of a method for forming a bulk acoustic wave resonator device 900 according to an embodiment of the present invention;

[0072] Figures 36 to 39 1 is a schematic structural diagram of each step of a method for forming a bulk acoustic wave resonator device 1000 according to an embodiment of the present invention;

[0073] Figures 40 to 43 1 is a schematic structural diagram of each step of a method for forming a bulk acoustic wave resonator device 1100 according to an embodiment of the present invention;

[0074] Figures 44 to 47 1 is a schematic structural diagram of each step of a method for forming a bulk acoustic wave resonator device 1200 according to an embodiment of the present invention;

[0075] Figures 48 to 51 1 is a schematic structural diagram of each step of a method for forming a bulk acoustic wave resonator device 1300 according to an embodiment of the present invention;

[0076] Figures 52 to 55 14 is a schematic structural diagram of each step of a method for forming a bulk acoustic wave resonator device 1400 according to an embodiment of the present invention;

[0077] Figure 56 15 is a schematic structural diagram of a wireless communication device 1500 . DETAILED DESCRIPTION

[0078] 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.

[0079] 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.

[0080] As described in the background technology section, there is edge capacitance between the upper electrode layer and the lower electrode layer outside the resonance region, which causes acoustic energy loss, thereby reducing the electromechanical coupling coefficient and Q value of the resonator.

[0081] The inventors of the present invention have discovered that a BAW resonant device includes a composite structure electrically connected to a first electrode layer or an edge structure of the first electrode. The composite structure includes an edge extension layer and a composite support layer. The composite support layer thickens the dielectric thickness between the edge extension layer and the second electrode layer, thereby reducing edge capacitance, improving the electromechanical coupling coefficient, blocking leakage waves, and improving the Q value. In addition, the edge structure and the composite structure can form a reflective structure located outside the electrode layer, thereby reflecting sound waves within the resonance region, blocking leakage waves, and improving the Q value.

[0082] An embodiment of the present invention provides a bulk acoustic wave resonator device, comprising: a first layer, the first layer including a cavity; a first electrode layer, at least one end of the first electrode layer being located in the cavity; a piezoelectric layer, located on the first electrode layer and covering the cavity, the piezoelectric layer including a first side and a second side opposite to the first side in a vertical direction, the first electrode layer being located on the first side; a second electrode layer, located on the second side and located on the piezoelectric layer, the overlapping portion of the second electrode layer with the first electrode layer being located above the cavity and corresponding to the cavity; and a first composite structure, located on the first side, contacting the piezoelectric layer, and being horizontally adjacent to the first electrode layer, the first end of the first composite structure close to the first electrode layer being located in the cavity, and the second end of the first composite structure, horizontally opposite to the first end of the first electrode layer and away from the first end, being embedded in the first layer, the first composite structure comprising a first edge extension layer and a first support layer, the first support layer being located between the piezoelectric layer and the first edge extension layer and used to reduce edge capacitance.

[0083] In some embodiments, the material of the first edge extension layer includes metal; the medium of the first supporting layer includes one of the following: non-metallic material, air, and vacuum.

[0084] In some embodiments, it also includes: a first edge structure located on the first side, contacting the piezoelectric layer, the first edge structure including a third side and a fourth side horizontally opposite to the third side, the first electrode layer is located on the third side, and the first composite structure is located on the fourth side.

[0085] In some embodiments, the first edge structure includes a first edge surrounding layer, a material of the first edge surrounding layer includes metal, the first edge surrounding layer is connected to the first electrode layer, and the first edge surrounding layer is further connected to the first edge extension layer.

[0086] In some embodiments, the first composite structure and the second electrode layer have a second overlapping portion, and a width of the second overlapping portion is equal to a width of the first edge structure.

[0087] In some embodiments, the first composite structure further includes a first edge portion, the first edge portion including a fifth side and a sixth side horizontally opposite to the fifth side, the first electrode layer is located on the fifth side, and the first edge extension layer and the first support layer are located on the sixth side.

[0088] In some embodiments, the thickness of the first edge portion is equal to the sum of the thicknesses of the first edge extension layer and the first supporting layer.

[0089] In some embodiments, the first edge extension layer, the first support layer, and the second electrode layer have a fourth overlapping portion, and a width of the fourth overlapping portion is equal to a width of the first edge portion.

[0090] In some embodiments, the first layer includes: an intermediate layer, the intermediate layer includes the cavity, wherein a material of the intermediate layer includes at least one of the following: a polymer, an insulating dielectric, and polysilicon.

[0091] It should be noted that the first composite structure is electrically connected to the first electrode layer or the edge structure of the first electrode. The first composite structure includes a first edge extension layer and a first composite support layer. The first composite support layer thickens the dielectric thickness between the first edge extension layer and the second electrode layer, thereby reducing the edge capacitance, improving the electromechanical coupling coefficient, blocking leakage waves, and improving the Q value.

[0092] An embodiment of the present invention also provides a method for forming a bulk acoustic wave resonator device, comprising: forming a piezoelectric layer, the piezoelectric layer including a first side and a second side opposite to the first side in a direction perpendicular to the first side; forming a first electrode layer, located on the first side; forming a first layer, located on the first side, the first electrode layer located between the first layer and the piezoelectric layer and embedded in the first layer; forming a second electrode layer, located on the second side; forming a first composite structure, located on the first side, contacting the piezoelectric layer, and horizontally adjacent to the first electrode layer, the first composite structure having a second end horizontally opposite to the first end of the first electrode layer and away from the first composite structure and embedded in the first layer, the forming of the first composite structure comprising: forming a first edge extension layer and a first supporting layer, the first supporting layer being located between the piezoelectric layer and the first edge extension layer for reducing edge capacitance; and forming a cavity, located on the first side, the cavity being located between the first layer and the piezoelectric layer and embedded in the first layer, the piezoelectric layer covering the cavity, at least one end of the first electrode layer being located within the cavity, and the first end of the first composite structure close to the first electrode layer being located within the cavity.

[0093] In some embodiments, forming the first layer includes: forming a sacrificial layer on the first side of the piezoelectric layer, the sacrificial layer covering a portion of the first electrode layer, and the sacrificial layer covering at least one end of the first electrode layer; forming a first bonding layer on the first side of the piezoelectric layer, the first bonding layer covering the sacrificial layer and the first electrode layer; providing a substrate; forming a second bonding layer on one side of the substrate; bonding the first bonding layer and the second bonding layer to form an intermediate layer, the substrate is located on the first side, and the intermediate layer is located between the substrate and the piezoelectric layer.

[0094] In some embodiments, the method further includes: providing a transition substrate; and forming the piezoelectric layer based on the transition substrate, wherein the transition substrate is located on the second side.

[0095] In some embodiments, the method further includes: after forming the first layer, removing the transition substrate; and after removing the transition substrate, forming the second electrode layer.

[0096] In some embodiments, forming the cavity includes removing the sacrificial layer, wherein removing the sacrificial layer includes wet etching the sacrificial layer.

[0097] In some embodiments, it also includes: before forming the first composite structure, forming a first edge structure, located on the first side, contacting the piezoelectric layer, the first edge structure including a third side and a fourth side horizontally opposite to the third side, the first electrode layer is located on the third side, and the first composite structure is located on the fourth side.

[0098] In some embodiments, forming the first edge structure includes forming a first edge surrounding layer, wherein the material of the first edge surrounding layer includes metal, the first edge surrounding layer is connected to the first electrode layer, and the first edge surrounding layer is also connected to the first edge extension layer.

[0099] In some embodiments, the first composite structure and the second electrode layer have a second overlapping portion, and a width of the second overlapping portion is equal to a width of the first edge structure.

[0100] In some embodiments, forming the first composite structure also includes: forming a first edge portion, the first edge portion including a fifth side and a sixth side horizontally opposite to the fifth side, the first electrode layer is located on the fifth side, and the first edge extension layer and the first support layer are located on the sixth side.

[0101] In some embodiments, the thickness of the first edge portion is equal to the sum of the thicknesses of the first edge extension layer and the first supporting layer.

[0102] In some embodiments, the first edge extension layer, the first support layer, and the second electrode layer have a fourth overlapping portion, and a width of the fourth overlapping portion is equal to a width of the first edge portion.

[0103] An embodiment of the present invention also provides a bulk acoustic wave resonance device, comprising: a first layer, the first layer including a cavity; a first electrode layer, at least one end of the first electrode layer being located in the cavity; a piezoelectric layer, located on the first electrode layer, covering the cavity, the piezoelectric layer including a first side and a second side opposite to the first side in a vertical direction, the first electrode layer being located on the first side; a second electrode layer, located on the second side, located on the piezoelectric layer, the overlapping portion of the second electrode layer with the first electrode layer being located above the cavity, corresponding to the cavity; and a second composite structure, located on the second side, contacting the piezoelectric layer, and being adjacent to the second electrode layer in a horizontal direction, the second composite structure having no overlapping portion or partially overlapping with the first electrode layer, the second composite structure including a second edge extension layer and a second support layer, the second support layer being located between the piezoelectric layer and the second edge extension layer, for reducing edge capacitance.

[0104] In some embodiments, the material of the second edge extension layer includes metal; the medium of the second supporting layer includes one of the following: non-metallic material, air, and vacuum.

[0105] In some embodiments, it also includes: a second edge structure located on the second side, contacting the piezoelectric layer, the second edge structure including a third side and a fourth side horizontally opposite to the third side, the second electrode layer is located on the third side, and the second composite structure is located on the fourth side.

[0106] In some embodiments, the second edge structure includes a second edge surrounding layer, the material of the second edge surrounding layer includes metal, the second edge surrounding layer is connected to the second electrode layer, and the second edge surrounding layer is further connected to the second edge extension layer.

[0107] In some embodiments, the second composite structure and the first electrode layer have a second overlapping portion, and a width of the second overlapping portion is equal to a width of the second edge structure.

[0108] In some embodiments, the second composite structure further includes a second edge portion, the second edge portion including a fifth side and a sixth side horizontally opposite to the fifth side, the second electrode layer is located on the fifth side, and the second edge extension layer and the second support layer are located on the sixth side.

[0109] In some embodiments, the thickness of the second edge portion is equal to the sum of the thicknesses of the second edge extension layer and the second supporting layer.

[0110] In some embodiments, the second edge extension layer, the second supporting layer, and the first electrode layer have a fourth overlapping portion, and a width of the fourth overlapping portion is equal to a width of the second edge portion.

[0111] It should be noted that the second composite structure is electrically connected to the second electrode layer or the edge structure corresponding to the second electrode layer. The second composite structure includes a second edge extension layer and a second composite support layer. The second composite support layer thickens the dielectric thickness between the second edge extension layer and the first electrode layer, thereby reducing the edge capacitance, improving the electromechanical coupling coefficient, blocking leakage waves, and improving the Q value.

[0112] In some embodiments, the first layer includes: an intermediate layer, the intermediate layer includes the cavity, wherein a material of the intermediate layer includes at least one of the following: a polymer, an insulating dielectric, and polysilicon.

[0113] An embodiment of the present invention also provides a method for forming a bulk acoustic wave resonator device, including: forming a piezoelectric layer, the piezoelectric layer including a first side and a second side opposite to the first side in a vertical direction; forming a first electrode layer, located on the first side; forming a first layer, located on the first side, the first electrode layer being located between the first layer and the piezoelectric layer and embedded in the first layer; forming a second electrode layer, located on the second side; forming a second composite structure, located on the second side, contacting the piezoelectric layer, and being adjacent to the second electrode layer in a horizontal direction, the second composite structure having no overlapping portion or partially overlapping with the first electrode layer, forming the second composite structure including: forming a second edge extension layer and a second supporting layer, the second supporting layer being located between the piezoelectric layer and the second edge extension layer for reducing edge capacitance; and forming a cavity, located on the first side, the cavity being located between the first layer and the piezoelectric layer and embedded in the first layer, the piezoelectric layer covering the cavity, and at least one end of the first electrode layer being located in the cavity.

[0114] In some embodiments, forming the first layer includes: forming a sacrificial layer on the first side of the piezoelectric layer, the sacrificial layer covering a portion of the first electrode layer, and the sacrificial layer covering at least one end of the first electrode layer; forming a first bonding layer on the first side of the piezoelectric layer, the first bonding layer covering the sacrificial layer and the first electrode layer; providing a substrate; forming a second bonding layer on one side of the substrate; bonding the first bonding layer and the second bonding layer to form an intermediate layer, the substrate is located on the first side, and the intermediate layer is located between the substrate and the piezoelectric layer.

[0115] In some embodiments, the method further includes: providing a transition substrate; and forming the piezoelectric layer based on the transition substrate, wherein the transition substrate is located on the second side.

[0116] In some embodiments, the method further includes: after forming the first layer, removing the transition substrate; and after removing the transition substrate, forming the second electrode layer.

[0117] In some embodiments, forming the cavity includes removing the sacrificial layer, wherein removing the sacrificial layer includes wet etching the sacrificial layer.

[0118] In some embodiments, the method further includes: before forming the second composite structure, forming a second edge structure, located on the second side, contacting the piezoelectric layer, the second edge structure including a third side and a fourth side horizontally opposite to the third side, the second electrode layer being located on the third side, and the second composite structure being located on the fourth side.

[0119] In some embodiments, forming the second edge structure includes: forming a second edge surrounding layer, wherein the material of the second edge surrounding layer includes metal, the second edge surrounding layer is connected to the second electrode layer, and the second edge surrounding layer is further connected to the second edge extension layer.

[0120] In some embodiments, the second composite structure and the first electrode layer have a second overlapping portion, and a width of the second overlapping portion is equal to a width of the second edge structure.

[0121] In some embodiments, forming the second composite structure also includes: forming a second edge portion, the second edge portion including a fifth side and a sixth side horizontally opposite to the fifth side, the second electrode layer is located on the fifth side, and the second edge extension layer and the second support layer are located on the sixth side.

[0122] In some embodiments, the thickness of the second edge portion is equal to the sum of the thicknesses of the second edge extension layer and the second supporting layer.

[0123] In some embodiments, the second edge extension layer, the second supporting layer, and the first electrode layer have a fourth overlapping portion, and a width of the fourth overlapping portion is equal to a width of the second edge portion.

[0124] An embodiment of the present invention further provides a filtering device, including but not limited to: a bulk acoustic wave resonator device provided by at least one of the above embodiments.

[0125] An embodiment of the present invention further provides a radio frequency front-end device, including but not limited to: a power amplifier device and at least one filtering device provided by the above embodiment; the power amplifier device is connected to the filtering device.

[0126] An embodiment of the present invention further provides a radio frequency front-end device, including but not limited to: a low-noise amplifier and at least one filtering device provided by the above embodiment; the low-noise amplifier is connected to the filtering device.

[0127] An embodiment of the present invention further provides a radio frequency front-end device, including but not limited to: a multiplexing device, wherein the multiplexing device includes at least one filtering device provided by the above embodiment.

[0128] Figures 3 to 55 Several specific embodiments of the present invention are shown, and the multiple specific embodiments form resonant devices of different structures. However, the present invention can also be implemented in other ways different from those described herein, so the present invention is not limited to the specific embodiments disclosed below.

[0129] Figures 3 to 6 1 is a schematic structural diagram of each step of a method for forming a bulk acoustic wave resonator 300 according to an embodiment of the present invention.

[0130] like Figure 3 As shown, an embodiment of the present invention provides a method for forming a bulk acoustic wave resonator device 300, including: providing a transition substrate 390; forming a piezoelectric layer 350 on the transition substrate 390, wherein the piezoelectric layer 350 includes a first side 351 and a second side 353 opposite to the first side 351, and the transition substrate 390 is located on the second side 353; forming a first electrode layer 340 on the first side 351 of the piezoelectric layer 350; and forming a sacrificial layer 3100 on the first side 351 of the piezoelectric layer 350, wherein the sacrificial layer 3100 covers a portion of the first electrode layer 340.

[0131] like Figure 4 As shown, a first bonding layer (unmarked) is formed on the first side 351 of the piezoelectric layer 350, and the first bonding layer covers the sacrificial layer 3100 and the first electrode layer 340; a substrate 310 is provided; a second bonding layer (unmarked) is formed on one side of the substrate 310; and the first bonding layer and the second bonding layer are bonded to form an intermediate layer 320.

[0132] like Figure 5 and Figure 6 As shown, Figure 6 yes Figure 5 Schematic diagram of the cross-sectional structure A, after bonding, the transition substrate 390 is removed; after removing the transition substrate 390, a second electrode layer 360 is formed on the second side 353 of the piezoelectric layer 350; a composite structure 370 is formed on the second side 353 of the piezoelectric layer 360; after forming the composite structure 370, the sacrificial layer 3100 is removed to form a cavity 330, and the intermediate layer 320 is embedded.

[0133] In this embodiment, forming the composite structure 370 includes: forming an edge extension layer 371, located on the second side 353, electrically connected to the second electrode layer 360, and forming a composite support layer 373, located on the second side 353, contacting the piezoelectric layer 350, located between the piezoelectric layer 350 and the edge extension layer 371, connecting the second electrode layer 360, and the composite support layer 373 overlaps with the edge extension layer 371.

[0134] In this embodiment, the composite structure 370 and the first electrode layer 340 have no overlapping portion.

[0135] It should be noted that the composite support layer 373 thickens the dielectric between the first electrode layer 340 and the edge extension layer 371, thereby reducing the edge capacitance 380 and improving the electromechanical coupling coefficient of the resonant device. Increasing the electromechanical coupling coefficient can increase the passband bandwidth of the filter device corresponding to the resonant device. In addition, see Figure 7 The acoustic impedance difference between the area C where the composite structure 370 is located and the area E where the second electrode layer 360 is located is greater than that in the case where there is no composite structure, thereby increasing the reflectivity of the edge lateral sound waves and improving the Q value.

[0136] In this embodiment, removing the sacrificial layer 3100 includes wet etching the sacrificial layer 3100 .

[0137] Figures 11 to 14 4 is a schematic structural diagram of each step of a method for forming a bulk acoustic wave resonator device 400 according to an embodiment of the present invention.

[0138] like Figure 11 As shown, an embodiment of the present invention provides a method for forming a bulk acoustic wave resonator device 400, including: providing a transition substrate 490; forming a piezoelectric layer 460 on the transition substrate 490, the piezoelectric layer 460 including a first side 461 and a second side 463 opposite to the first side 460, the transition substrate 490 being located on the second side 463; forming a first electrode layer 440 on the first side 461 of the piezoelectric layer 460; forming a composite structure 450 on the first side 461 of the piezoelectric layer 460; and forming a sacrificial layer 4100 on the first side 461 of the piezoelectric layer 460, the sacrificial layer 4100 covering the first electrode layer 440 and a portion of the composite structure 450.

[0139] like Figure 12As shown, a first bonding layer (unmarked) is formed on the first side 461 of the piezoelectric layer 460, and the first bonding layer covers the sacrificial layer 4100 and the composite structure 450; a substrate 410 is provided; a second bonding layer (unmarked) is formed on one side of the substrate 410; and the first bonding layer and the second bonding layer are bonded to form an intermediate layer 420.

[0140] like Figure 13 and Figure 14 As shown, Figure 14 yes Figure 13 Schematic diagram of the cross-sectional structure A, after bonding, the transition substrate 490 is removed; after removing the transition substrate 490, a second electrode layer 470 is formed on the second side 463 of the piezoelectric layer 460; after forming the second electrode layer 470, the sacrificial layer 4100 is removed to form a cavity 430, and the intermediate layer 420 is embedded.

[0141] In this embodiment, forming the composite structure 450 includes: forming an edge extension layer 451, located on the first side 461, electrically connected to the first electrode layer 440, and forming a composite support layer 453, located on the first side 461, contacting the piezoelectric layer 460, located between the edge extension layer 451 and the piezoelectric layer 460, connecting the first electrode layer 440, and the composite support layer 453 overlaps with the edge extension layer 451.

[0142] In this embodiment, the composite structure 450 and the second electrode layer 470 have no overlapping portion.

[0143] It should be noted that the composite support layer 453 thickens the medium between the second electrode layer 470 and the edge extension layer 451, thereby reducing the edge capacitance 480, improving the electromechanical coupling coefficient of the resonant device, and the composite structure 450 can block leakage waves and improve the Q value.

[0144] In this embodiment, removing the sacrificial layer 4100 includes wet etching the sacrificial layer 4100 .

[0145] Figures 15 to 18 1 is a schematic structural diagram of each step of a method for forming a bulk acoustic wave resonator 500 according to an embodiment of the present invention.

[0146] like Figure 15As shown, an embodiment of the present invention provides a method for forming a bulk acoustic wave resonator device 500, including: providing a transition substrate 5100; forming a piezoelectric layer 560 on the transition substrate 5100, the piezoelectric layer 560 including a first side 561 and a second side 563 opposite to the first side 561, the transition substrate 5100 being located on the second side 563; forming a first electrode layer 540 on the first side 561 of the piezoelectric layer 560; forming a first composite structure 550 on the first side 561 of the piezoelectric layer 560; and forming a sacrificial layer 5110 on the first side 561 of the piezoelectric layer 560, the sacrificial layer 5110 covering the first electrode layer 540 and a portion of the first composite structure 550.

[0147] like Figure 16 As shown, a first bonding layer (unmarked) is formed on the first side 561 of the piezoelectric layer 560, and the first bonding layer covers the sacrificial layer 5110 and the first composite structure 550; a substrate 510 is provided; a second bonding layer (unmarked) is formed on one side of the substrate 510; and the first bonding layer and the second bonding layer are bonded to form an intermediate layer 520.

[0148] like Figure 17 and Figure 18 As shown, Figure 18 yes Figure 17 Schematic diagram of the cross-sectional structure A, after bonding, the transition substrate 5100 is removed; after removing the transition substrate 5100, a second electrode layer 570 is formed on the second side 563 of the piezoelectric layer 560; a second composite structure 580 is formed on the second side 563 of the piezoelectric layer 560; after forming the second composite structure 580, the sacrificial layer 5110 is removed to form a cavity 530, which is embedded in the intermediate layer 520.

[0149] In this embodiment, forming the first composite structure 550 includes: forming a first edge extension layer 551, located on the first side 561, electrically connected to the first electrode layer 540, and forming a first composite support layer 553, located on the first side 561, contacting the piezoelectric layer 560, located between the piezoelectric layer 560 and the first edge extension layer 531, connecting the first electrode layer 540, and the first composite support layer 553 overlaps the first edge extension layer 551.

[0150] In this embodiment, forming the second composite structure 580 includes: forming a second edge extension layer 581, located on the second side 563, electrically connected to the second electrode layer 570, and forming a second composite support layer 583, located on the second side 563, contacting the piezoelectric layer 560, located between the piezoelectric layer 560 and the second edge extension layer 581, connecting the second electrode layer 570, and the second composite support layer 583 overlaps with the second edge extension layer 581.

[0151] In this embodiment, there is no overlap between the first composite structure 550 and the second composite structure 580. In this embodiment, the first composite structure 550 and the second composite structure 580 are located on both sides of the overlap between the first electrode layer 540 and the second electrode layer 570.

[0152] It should be noted that the first composite support layer 553 thickens the medium between the second electrode layer 570 and the first edge extension layer 551, reducing the edge capacitance 590, and the second composite support layer 583 thickens the medium between the first electrode layer 540 and the second edge extension layer 581, reducing the edge capacitance 591, thereby improving the electromechanical coupling coefficient of the resonant device and the first composite structure 550 can block leakage waves and improve the Q value.

[0153] In this embodiment, removing the sacrificial layer 5110 includes: wet etching the sacrificial layer 5110 .

[0154] Figures 19 to 22 1 is a schematic structural diagram of each step of a method for forming a bulk acoustic wave resonator device 600 according to an embodiment of the present invention.

[0155] like Figure 19 As shown, an embodiment of the present invention provides a method for forming a bulk acoustic wave resonator device 600, including: providing a transition substrate 690; forming a piezoelectric layer 650 on the transition substrate 690, wherein the piezoelectric layer 650 includes a first side 651 and a second side 653 opposite to the first side 651, and the transition substrate 690 is located on the second side 653; forming a first electrode layer 640 on the first side 651 of the piezoelectric layer 650; and forming a sacrificial layer 6100 on the first side 651 of the piezoelectric layer 650, wherein the sacrificial layer 6100 covers a portion of the first electrode layer 640.

[0156] like Figure 20 As shown, a first bonding layer (unmarked) is formed on the first side 651 of the piezoelectric layer 650, and the first bonding layer covers the sacrificial layer 6100 and the first electrode layer 640; a substrate 610 is provided; a second bonding layer (unmarked) is formed on one side of the substrate 610; and the first bonding layer and the second bonding layer are bonded to form an intermediate layer 620.

[0157] like Figure 21 and Figure 22 As shown, Figure 22 yes Figure 21 Schematic diagram of the cross-sectional structure A, after bonding, the transition substrate 690 is removed; after removing the transition substrate 690, a second electrode layer 660 is formed on the second side 653 of the piezoelectric layer 650; an edge structure 670 is formed on the second side 653 of the piezoelectric layer 650; a composite structure 680 is formed on the second side 653 of the piezoelectric layer 650; after forming the composite structure 680, the sacrificial layer 6100 is removed to form a cavity 630, and the intermediate layer 620 is embedded.

[0158] In this embodiment, the second electrode layer 660 is located inside the edge structure 670 (ie, facing the side of the central axis of the BAW resonator 600 ), and the edge structure 670 and the first electrode layer 640 have an overlapping portion.

[0159] In this embodiment, forming the edge structure 670 includes: forming an edge surrounding layer, located on the second side 653, and the edge surrounding layer is electrically connected to the second electrode layer 660; and forming an edge supporting layer, located on the second side 653, contacting the piezoelectric layer 650, and located between the piezoelectric layer 650 and the edge surrounding layer, the edge supporting layer is connected to the second electrode layer 660, and the edge surrounding layer and the edge supporting layer overlap.

[0160] In this embodiment, the composite structure 680 is located outside the edge structure 670 (i.e., pointing to the side opposite to the central axis of the bulk acoustic wave resonator 600) and connected to the edge structure 670. The formation of the composite structure 680 includes: forming an edge extension layer 681, located on the second side 653, electrically connected to the edge structure 670; and forming a composite support layer 683, located on the second side 653, contacting the piezoelectric layer 650, located between the piezoelectric layer 650 and the edge extension layer 681, connecting the edge structure 670, and the composite support layer 683 overlaps with the edge extension layer 681.

[0161] In this embodiment, the thickness of the composite structure 680 is greater than the thickness of the edge structure 670. In another embodiment, the thickness of the composite structure on the second electrode layer side is equal to the thickness of the edge structure on the second electrode layer side. In another embodiment, the thickness of the composite structure on the second electrode layer side is less than the thickness of the edge structure on the second electrode layer side.

[0162] In this embodiment, the composite structure 680 and the first electrode layer 640 have no overlapping portion.

[0163] It should be noted that the composite support layer 683 thickens the dielectric between the first electrode layer 640 and the edge extension layer 681, thereby reducing the edge capacitance between the first electrode layer 640 and the edge extension layer 681 and improving the electromechanical coupling coefficient of the resonant device. Figure 23 As shown, the acoustic impedance of the region F where the edge structure 670 is located is greater than that of the region E where the second electrode layer 660 is located, the acoustic impedance of the region F is greater than the acoustic impedance of air and vacuum, the acoustic impedance of the region F is greater than the acoustic impedance of the region C where the composite structure 680 is located, and the acoustic impedance of the region C is less than the acoustic impedance of the region E. The composite structure 680 can make the acoustic impedance of the region C closer to the acoustic impedance of air and vacuum, so that it can more effectively reflect the sound waves at the edge of the resonance area, block leakage waves, and improve the Q value.

[0164] In this embodiment, removing the sacrificial layer 6100 includes wet etching the sacrificial layer 6100 .

[0165] Figures 24 to 27 1 is a schematic structural diagram of each step of a method for forming a bulk acoustic wave resonator device 700 according to an embodiment of the present invention.

[0166] like Figure 24 As shown, an embodiment of the present invention provides a method for forming a bulk acoustic wave resonator device 700, including: providing a transition substrate 790; forming a piezoelectric layer 770 on the transition substrate 790, the piezoelectric layer 770 including a first side 771 and a second side 773 opposite to the first side 771, the transition substrate 790 being located on the second side 773; forming a first electrode layer 740 on the first side 770 of the piezoelectric layer 770; forming an edge structure 750 on the first side 771 of the piezoelectric layer 770; forming a composite structure 760 on the first side 771 of the piezoelectric layer 770; and forming a sacrificial layer 7100 on the first side 771 of the piezoelectric layer 770, the sacrificial layer 7100 covering the first electrode layer 740, the edge structure 750 and a portion of the composite structure 760.

[0167] like Figure 25 As shown, a first bonding layer (unmarked) is formed on the first side 771 of the piezoelectric layer 770, and the first bonding layer covers the sacrificial layer 7100 and the composite structure 760; a substrate 710 is provided; a second bonding layer (unmarked) is formed on one side of the substrate 710; and the first bonding layer and the second bonding layer are bonded to form an intermediate layer 720.

[0168] like Figure 26 and Figure 27 As shown, Figure 27 yes Figure 26Schematic diagram of the cross-sectional structure A, after bonding, the transition substrate 790 is removed; after removing the transition substrate 790, a second electrode layer 780 is formed on the second side 773 of the piezoelectric layer 770; after forming the second electrode layer 780, the sacrificial layer 7100 is removed to form a cavity 730, and the intermediate layer 720 is embedded.

[0169] In this embodiment, the edge structure 750 is located in the cavity 730 , and the first electrode layer 740 is located inside the edge structure 750 (ie, facing the side of the central axis of the BAW resonator 700 ).

[0170] In this embodiment, forming the edge structure 750 includes forming an edge surrounding layer, which is located in the cavity 730, and the edge surrounding layer is electrically connected to the first electrode layer 740; and forming an edge supporting layer, which is located on the first side 771, contacts the piezoelectric layer 770, is located between the edge surrounding layer and the piezoelectric layer 770, and the edge supporting layer is connected to the first electrode layer 740, and the edge surrounding layer and the edge supporting layer overlap.

[0171] In this embodiment, the composite structure 760 is located outside the edge structure 750 (i.e., pointing to the side opposite to the central axis of the bulk acoustic wave resonator 700), and the first end of the composite structure 760 is connected to the edge structure 750. Formation of the composite structure 760 includes: forming an edge extension layer 761, located on the first side 771, electrically connected to the edge structure 750; and forming a composite support layer 763, located on the first side 771, contacting the piezoelectric layer 770, located between the edge extension layer 761 and the piezoelectric layer 770, connecting the edge structure 750, and the composite support layer 763 overlaps with the edge extension layer 761.

[0172] In this embodiment, the thickness of the composite structure 760 is greater than the thickness of the edge structure 750. In another embodiment, the thickness of the composite structure on the first electrode layer side is equal to the thickness of the edge structure on the first electrode layer side. In another embodiment, the thickness of the composite structure on the first electrode layer side is less than the thickness of the edge structure on the first electrode layer side.

[0173] In this embodiment, the composite structure 760 and the second electrode layer 780 have no overlapping portion.

[0174] It should be noted that the composite support layer 763 thickens the medium between the second electrode layer 780 and the edge extension layer 761, thereby reducing the edge capacitance between the second electrode layer 780 and the edge extension layer 761, and improving the electromechanical coupling coefficient of the resonant device. In addition, the acoustic impedance of the edge region where the edge structure 750 is located is greater than the acoustic impedance of the inner region where the first electrode layer 740 is located, the acoustic impedance of the edge region is greater than the acoustic impedance of air and vacuum, the acoustic impedance of the edge region is greater than the acoustic impedance of the outer region where the composite structure 760 is located, and the acoustic impedance of the outer region is less than the acoustic impedance of the inner region. The composite structure 760 can make the acoustic impedance of the outer region closer to the acoustic impedance of air and vacuum, thereby more effectively reflecting the sound waves at the edge of the resonance region, blocking leakage waves, and improving the Q value.

[0175] In this embodiment, removing the sacrificial layer 7100 includes wet etching the sacrificial layer 7100 .

[0176] Figures 28 to 31 1 is a schematic structural diagram of each step of a method for forming a bulk acoustic wave resonator 800 according to an embodiment of the present invention.

[0177] like Figure 28 As shown, an embodiment of the present invention provides a method for forming a bulk acoustic wave resonator device 800, including: providing a transition substrate 8100; forming a piezoelectric layer 870 on the transition substrate 8100, the piezoelectric layer 870 including a first side 871 and a second side 873 opposite to the first side 871, and the transition substrate 8100 is located on the second side 873; forming a first electrode layer 840 on the first side 871 of the piezoelectric layer 870; forming a first edge structure 850 on the first side 871 of the piezoelectric layer 870; forming a first composite structure 860 on the first side 871 of the piezoelectric layer 870; and forming a sacrificial layer 8110 on the first side 871 of the piezoelectric layer 870, the sacrificial layer 8110 covering the first electrode layer 840, the first edge structure 850 and a portion of the first composite structure 860.

[0178] like Figure 29 As shown, a first bonding layer (unmarked) is formed on the first side 871 of the piezoelectric layer 870, and the first bonding layer covers the sacrificial layer 8110 and the first composite structure 860; a substrate 810 is provided; a second bonding layer (unmarked) is formed on one side of the substrate 810; and the first bonding layer and the second bonding layer are bonded to form an intermediate layer 820.

[0179] like Figure 30 and Figure 31 As shown, Figure 31 yes Figure 30Schematic diagram of the cross-sectional structure A, after bonding, the transition substrate 8100 is removed; after removing the transition substrate 8100, a second electrode layer 880 is formed on the second side 873 of the piezoelectric layer 870; a second edge structure 851 is formed on the second side 873 of the piezoelectric layer 870; a second composite structure 890 is formed on the second side 873 of the piezoelectric layer 870; after forming the second composite structure 890, the sacrificial layer 8110 is removed to form a cavity 830, which is embedded in the intermediate layer 820.

[0180] In this embodiment, the first edge structure 850 is located in the cavity 830 , and the first electrode layer 840 is located inside the first edge structure 850 (ie, facing the side of the central axis of the BAW resonator 800 ).

[0181] In this embodiment, forming the first edge structure 850 includes forming a first edge surrounding layer (unmarked), which is located in the cavity 830, and the first edge surrounding layer is electrically connected to the first electrode layer 840; and forming a first edge supporting layer (unmarked), which is located on the first side 871, contacts the piezoelectric layer 870, is located between the piezoelectric layer 870 and the first edge surrounding layer, and the first edge supporting layer is connected to the first electrode layer 840, and the first edge surrounding layer and the first edge supporting layer overlap.

[0182] In this embodiment, the first composite structure 860 is located outside the first edge structure 850 (i.e., pointing to the side opposite to the central axis of the bulk acoustic wave resonator 800), and the first end of the first composite structure 860 is connected to the first edge structure 850; forming the first composite structure 860 includes: forming a first edge extension layer 861, located on the first side 871, electrically connected to the first edge structure 850, and forming a first composite support layer 863, located on the first side 871, contacting the piezoelectric layer 870, located between the first edge extension layer 831 and the piezoelectric layer 870, connecting the first edge structure 850, and the first composite support layer 863 overlaps with the first edge extension layer 861.

[0183] In this embodiment, the thickness of the first composite structure 860 is greater than the thickness of the first edge structure 850. In another embodiment, the thickness of the first composite structure on the first electrode layer side is equal to the thickness of the first edge structure on the first electrode layer side. In another embodiment, the thickness of the first composite structure on the first electrode layer side is less than the thickness of the first edge structure on the first electrode layer side.

[0184] In this embodiment, the first composite structure 860 and the second electrode layer 880 have no overlapping portion.

[0185] In this embodiment, the second electrode layer 880 is located on the inner side of the second edge structure 851 (ie, facing the side of the central axis of the BAW resonator 800 ).

[0186] In this embodiment, forming the second edge structure 851 includes forming a second edge surrounding layer (unmarked), located on the second side 873, and the second edge surrounding layer is electrically connected to the second electrode layer 880; and forming a second edge supporting layer (unmarked), located on the second side 873, contacting the piezoelectric layer 870, located between the piezoelectric layer 870 and the second edge surrounding layer, the second edge supporting layer is connected to the second electrode layer 880, and the second edge surrounding layer and the second edge supporting layer overlap.

[0187] In this embodiment, the second edge structure 851 and the first electrode layer 840 have an overlapping portion; the second composite structure 890 is located outside the second edge structure 851 (i.e., pointing to the side opposite to the central axis of the bulk acoustic wave resonator 800) and connected to the second edge structure 851; forming the second composite structure 890 includes: forming a second edge extension layer 891, located on the second side 873, electrically connected to the second edge structure 851, and forming a second composite support layer 893, located on the second side 873, contacting the piezoelectric layer 870, located between the piezoelectric layer 870 and the second edge extension layer 891, connecting the second edge structure 851, and the second composite support layer 893 overlapping with the second edge extension layer 891.

[0188] In this embodiment, the first edge structure 850 is located outside the edge of the first electrode layer 840, and the second edge structure 851 is located outside the edge of the second electrode layer 880. The first edge structure 850 and the second edge structure 851 have an overlapping portion to form a surrounding edge.

[0189] In this embodiment, the thickness of the second composite structure 890 is greater than the thickness of the second edge structure 851. In another embodiment, the thickness of the second composite structure on the second electrode layer side is equal to the thickness of the second edge structure on the second electrode layer side. In another embodiment, the thickness of the second composite structure on the second electrode layer side is less than the thickness of the second edge structure on the second electrode layer side.

[0190] In this embodiment, the second composite structure 890 and the first electrode layer 840 have no overlapping portion.

[0191] In this embodiment, the second composite structure 890 has no overlapping portion with the first composite structure 860. In this embodiment, the second composite structure 890 and the first composite structure 860 are located on both sides of the second electrode layer 880.

[0192] It should be noted that the first composite support layer 863 thickens the medium between the second electrode layer 880 and the first edge extension layer 861, reducing the edge capacitance between the second electrode layer 880 and the first edge extension layer 861, and the second composite support layer 893 thickens the medium between the first electrode layer 840 and the second edge extension layer 891, reducing the edge capacitance between the first electrode layer 840 and the second edge extension layer 891, thereby improving the electromechanical coupling coefficient of the resonant device.

[0193] In addition, the acoustic impedance of the first edge region where the first edge structure 850 is located is greater than that of the inner region where the first electrode layer 840 is located, and the acoustic impedance of the first edge region is greater than that of the first outer region where the first composite structure 860 is located, and the acoustic impedance of the first outer region is smaller than that of the inner region. The first composite structure 860 can make the acoustic impedance of the first outer region closer to the acoustic impedance of air and vacuum; the acoustic impedance of the second edge region where the second edge structure 851 is located is greater than that of the inner region where the second electrode layer 880 is located, and the acoustic impedance of the second edge region is greater than that of the second outer region where the second composite structure 890 is located, and the acoustic impedance of the second outer region is smaller than that of the inner region. The second composite structure 890 can make the acoustic impedance of the second outer region closer to the acoustic impedance of air and vacuum; thereby, the sound waves at the edge of the resonance zone can be more effectively reflected, leakage waves can be blocked, and the Q value can be improved.

[0194] In this embodiment, removing the sacrificial layer 8110 includes: wet etching the sacrificial layer 8110 .

[0195] Figures 32 to 35 1 is a schematic structural diagram of each step of a method for forming a bulk acoustic wave resonator device 900 according to an embodiment of the present invention.

[0196] like Figure 32 As shown, an embodiment of the present invention provides a method for forming a bulk acoustic wave resonator device 900, including: providing a transition substrate 990; forming a piezoelectric layer 950 on the transition substrate 990, wherein the piezoelectric layer 950 includes a first side 951 and a second side 953 opposite to the first side 951, and the transition substrate 990 is located on the second side 953; forming a first electrode layer 940 on the first side 951 of the piezoelectric layer 950; and forming a sacrificial layer 9100 on the first side 951 of the piezoelectric layer 950, wherein the sacrificial layer 9100 covers a portion of the first electrode layer 940.

[0197] like Figure 33As shown, a first bonding layer (unmarked) is formed on the first side 951 of the piezoelectric layer 950, and the first bonding layer covers the sacrificial layer 9100 and the first electrode layer 940; a substrate 910 is provided; a second bonding layer (unmarked) is formed on one side of the substrate 910; and the first bonding layer and the second bonding layer are bonded to form an intermediate layer 920.

[0198] like Figure 34 and Figure 35 As shown, Figure 35 yes Figure 34 Schematic diagram of the cross-sectional structure A, after bonding, the transition substrate 990 is removed; after removing the transition substrate 990, a second electrode layer 960 is formed on the second side 952 of the piezoelectric layer 950; an edge structure 970 is formed on the second side 952 of the piezoelectric layer 950; a composite structure 980 is formed on the second side 953 of the piezoelectric layer 950; after forming the composite structure 980, the sacrificial layer 9100 is removed to form a cavity 930, and the intermediate layer 920 is embedded.

[0199] In this embodiment, the edge structure 970 is located on the second side 953 , the second electrode layer 960 is located on the inner side of the edge structure 970 (i.e., the side pointing to the central axis of the BAW resonator 900 ), and the edge structure 970 and the first electrode layer 940 have an overlapping portion.

[0200] In this embodiment, the edge structure 970 includes an edge surrounding layer (unmarked), located on the second side 953, and the edge surrounding layer is electrically connected to the second electrode layer 960; and an edge supporting layer (unmarked), located on the second side 953, contacting the piezoelectric layer 950, and located between the piezoelectric layer 950 and the edge surrounding layer, the edge supporting layer is connected to the second electrode layer 960, and the edge surrounding layer and the edge supporting layer overlap.

[0201] In this embodiment, the composite structure 980 is located outside the edge structure 970 (i.e., pointing to the side opposite to the central axis of the bulk acoustic wave resonator 900) and connected to the edge structure 970; wherein, the composite structure 980 includes: an edge extension layer 981, located on the second side 953, electrically connected to the edge structure 970, and a composite support layer 983, located on the second side 953, contacting the piezoelectric layer 950, located between the piezoelectric layer 950 and the edge extension layer 981, connecting the edge structure 970, the composite support layer 983 overlaps with the edge extension layer 981, and the edge The extension layer 981 and the composite support layer 983 have a first overlapping portion with the first electrode layer 940; the composite structure 980 also includes an edge extension layer 985, located on the second side 953, electrically connected to the edge structure 970, and a composite support layer 987, located on the second side 953, contacting the piezoelectric layer 950, located between the piezoelectric layer 950 and the edge extension layer 985, connecting the edge structure 970, the composite support layer 987 overlaps with the edge extension layer 985, and the edge extension layer 985 and the composite support layer 987 have a second overlapping portion with the first electrode layer 940.

[0202] In this embodiment, the thickness of the composite structure 980 is greater than the thickness of the edge structure 970. In another embodiment, the thickness of the composite structure on the second electrode layer side is equal to the thickness of the edge structure on the second electrode layer side. In another embodiment, the thickness of the composite structure on the second electrode layer side is less than the thickness of the edge structure on the second electrode layer side.

[0203] In this embodiment, the edge extension layer 981 and the edge extension layer 985 have no overlapping portion. In this embodiment, the edge extension layer 981 and the edge extension layer 985 are located on both sides of the second electrode layer 960.

[0204] In this embodiment, the width of the first overlapping portion is equal to the width of the edge structure 970 , and the width of the second overlapping portion is equal to the width of the edge structure 970 .

[0205] It should be noted that the composite support layer 983 thickens the medium between the first electrode layer 940 and the edge extension layer 981, reducing the edge capacitance between the first electrode layer 940 and the edge extension layer 981, and the composite support layer 987 thickens the medium between the first electrode layer 940 and the edge extension layer 985, reducing the edge capacitance between the first electrode layer 940 and the edge extension layer 985, thereby improving the electromechanical coupling coefficient of the resonant device.

[0206] In addition, the edge structure 970 and the composite structure 980 form a reflective structure, which is located outside the second electrode layer 960, thereby reflecting the sound waves in the resonance region, blocking leakage waves, and improving the Q value.

[0207] In this embodiment, removing the sacrificial layer 9100 includes wet etching the sacrificial layer 9100 .

[0208] Figures 36 to 39 1 is a schematic structural diagram of each step of a method for forming a bulk acoustic wave resonator device 1000 according to an embodiment of the present invention.

[0209] like Figure 36 As shown, an embodiment of the present invention provides a method for forming a bulk acoustic wave resonator device 1000, including: providing a transition substrate 1090; forming a piezoelectric layer 1070 on the transition substrate 1090, the piezoelectric layer 1070 including a first side 1071 and a second side 1073 opposite to the first side 1071, the transition substrate 1090 being located on the second side 1073; forming a first electrode layer 1040 on the first side 1071 of the piezoelectric layer 1070; forming an edge structure 1050 on the first side 1071 of the piezoelectric layer 1070; forming a composite structure 1060 on the first side 1071 of the piezoelectric layer 1070; and forming a sacrificial layer 10100 on the first side 1071 of the piezoelectric layer 1070, the sacrificial layer 10100 covering the first electrode layer 1040, the edge structure 1050 and a portion of the composite structure 1060.

[0210] like Figure 37 As shown, a first bonding layer (unmarked) is formed on the first side 1071 of the piezoelectric layer 1070, and the first bonding layer covers the sacrificial layer 10100 and the composite structure 1060; a substrate 1010 is provided; a second bonding layer (unmarked) is formed on one side of the substrate 1010; and the first bonding layer and the second bonding layer are bonded to form an intermediate layer 1020.

[0211] like Figure 38 and Figure 39 As shown, Figure 39 yes Figure 38 Schematic diagram of the cross-sectional structure A, after bonding, the transition substrate 1090 is removed; after removing the transition substrate 1090, a second electrode layer 1080 is formed on the second side 1072 of the piezoelectric layer 1070; after forming the second electrode layer 1080, the sacrificial layer 10100 is removed, and a cavity 1030 is formed in the intermediate layer 1020.

[0212] In this embodiment, the edge structure 1050 is located in the cavity 1030 , and the first electrode layer 1040 is located inside the edge structure 1050 (ie, facing the side of the central axis of the BAW resonator 1000 ).

[0213] In this embodiment, the edge structure 1050 includes an edge surrounding layer, which is located in the cavity 1030 and is electrically connected to the first electrode layer 1040; and an edge supporting layer, which is located in the cavity 1030 and is located between the edge surrounding layer and the piezoelectric layer 1070, and is connected to the first electrode layer 1040, and the edge surrounding layer and the edge supporting layer overlap.

[0214] In this embodiment, the edge structure 1050 and the second electrode layer 1080 have an overlapping portion.

[0215] In this embodiment, the composite structure 1060 is located outside the edge structure 1050 (i.e., pointing to the side opposite to the central axis of the bulk acoustic wave resonator 1000), and the first end of the composite structure 1060 is located in the cavity 1030; wherein, the composite structure 1060 includes an edge extension layer 1061, which is electrically connected to the edge structure 1050, and a composite support layer 1063, which is located between the edge extension layer 1061 and the piezoelectric layer 1070, and connects the edge structure 1050, the composite support layer 1063 overlaps with the edge extension layer 1061; wherein, the composite structure 1060 also includes an edge extension layer 1065, located in the cavity 1030, electrically connected to the edge structure 1050, and a composite support layer 1067, located between the edge extension layer 1061 and the piezoelectric layer 1070, located in the cavity 1030, connected to the edge structure 1050, and the composite support layer 1067 overlaps with the edge extension layer 1065.

[0216] In this embodiment, the thickness of the composite structure 1060 is greater than the thickness of the edge structure 1050. In another embodiment, the thickness of the composite structure on the first electrode layer side is equal to the thickness of the edge structure on the first electrode layer side. In another embodiment, the thickness of the composite structure on the first electrode layer side is less than the thickness of the edge structure on the first electrode layer side.

[0217] In this embodiment, the edge extension layer 1061 and the edge extension layer 1065 have no overlapping portion. In this embodiment, the edge extension layer 1061 and the edge extension layer 1065 are located on both sides of the first electrode layer 1040.

[0218] In this embodiment, the edge extension layer 1061 and the composite support layer 1063 have a first overlapping portion with the second electrode layer 1080 , and the edge extension layer 1065 and the composite support layer 1067 have a second overlapping portion with the second electrode layer 1080 .

[0219] In this embodiment, the width of the first overlapping portion is equal to the width of the edge structure 1050 , and the width of the second overlapping portion is equal to the width of the edge structure 1050 .

[0220] It should be noted that the composite support layer 1063 thickens the medium between the second electrode layer 1080 and the edge extension layer 1061, reducing the edge capacitance between the second electrode layer 1080 and the edge extension layer 1061, and the composite support layer 1067 thickens the medium between the second electrode layer 1080 and the edge extension layer 1065, reducing the edge capacitance between the second electrode layer 1080 and the edge extension layer 1065, thereby improving the electromechanical coupling coefficient of the resonant device.

[0221] In addition, the edge structure 1050 and the composite structure 1060 form a reflective structure, which is located outside the first electrode layer 1040, thereby reflecting the sound waves in the resonance region, blocking leakage waves, and improving the Q value.

[0222] In this embodiment, removing the sacrificial layer 10100 includes: wet etching the sacrificial layer 10100 .

[0223] Figures 40 to 43 1 is a schematic structural diagram of each step of a method for forming a bulk acoustic wave resonator device 1100 according to an embodiment of the present invention.

[0224] like Figure 40 As shown, an embodiment of the present invention provides a method for forming a bulk acoustic wave resonator device 1100, comprising: providing a transition substrate 11100; forming a piezoelectric layer 1170 on the transition substrate 11100, wherein the piezoelectric layer 1170 includes a first side 1171 and a second side 1173 opposite to the first side 1171, and the transition substrate 11100 is located on the second side 1173; forming a first electrode layer 1140 on the first side 1171 of the piezoelectric layer 1170; forming a first edge structure 1150 on the first side 1171 of the piezoelectric layer 1170; forming a first composite structure 1160 on the first side 1171 of the piezoelectric layer 1170; and forming a sacrificial layer 11110 on the first side 1171 of the piezoelectric layer 1170, wherein the sacrificial layer 11110 covers the first electrode layer 1140, the first edge structure 1150 and a portion of the first composite structure 1160.

[0225] like Figure 41As shown, a first bonding layer (unmarked) is provided on the first side 1171 of the piezoelectric layer 1170, and the first bonding layer covers the sacrificial layer 11110 and the first composite structure 1160; a substrate 1110 is provided; a second bonding layer (unmarked) is formed on one side of the substrate 1110; and the first bonding layer and the second bonding layer are bonded to form an intermediate layer 1120.

[0226] like Figure 42 and Figure 43 As shown, Figure 43 yes Figure 42 Schematic diagram of the cross-sectional structure A, after bonding, the transition substrate 11100 is removed; after removing the transition substrate 11100, a second electrode layer 1180 is formed on the second side 1173 of the piezoelectric layer 1170; a second edge structure 1151 is formed on the second side 1173 of the piezoelectric layer 1170; a second composite structure 1190 is formed on the second side 1173 of the piezoelectric layer 1170; after forming the second composite structure 1190, the sacrificial layer 11110 is removed to form a cavity 1130, which is embedded in the intermediate layer 1120.

[0227] In this embodiment, the first edge structure 1150 is located in the cavity 1130 , and the first electrode layer 1140 is located inside the first edge structure 1150 (ie, facing the side of the central axis of the BAW resonator 1100 ).

[0228] In this embodiment, the first edge structure 1150 includes a first edge surrounding layer (unmarked), located in the cavity 1130, and the first edge surrounding layer is electrically connected to the first electrode layer 1140; and a first edge supporting layer (unmarked), located in the cavity 1130, contacting the piezoelectric layer 1170, and located between the piezoelectric layer 1170 and the first edge surrounding layer, the first edge supporting layer is connected to the first electrode layer 1140, and the first edge surrounding layer and the first edge supporting layer overlap.

[0229] In this embodiment, the first edge structure 1150 and the second electrode layer 1180 have an overlapping portion.

[0230] In this embodiment, the first composite structure 1160 is located outside the first edge structure 1150 (i.e., pointing to the side opposite to the central axis of the bulk acoustic wave resonator 1100), and the first end of the first composite structure 1160 is connected to the first edge structure 1150; the first composite structure 1160 includes: a first edge extension layer 1161, located on the first side 1171, electrically connected to the first edge structure 1150, and a first composite support layer 1163, located on the first side 1171, contacting the piezoelectric layer 1170, located between the first edge extension layer 1161 and the piezoelectric layer 1170, connecting the first edge structure 1150, and the first composite support layer 1163 overlaps with the first edge extension layer 1161.

[0231] In this embodiment, the thickness of the first composite structure 1160 is greater than the thickness of the first edge structure 1150. In another embodiment, the thickness of the first composite structure on the first electrode layer side is equal to the thickness of the first edge structure on the first electrode layer side. In another embodiment, the thickness of the first composite structure on the first electrode layer side is less than the thickness of the first edge structure on the first electrode layer side.

[0232] In this embodiment, the first edge extension layer 1161 and the first composite support layer 1163 have a first overlapping portion with the second electrode layer 1180 .

[0233] In this embodiment, the second electrode layer 1180 is located inside the second edge structure 1151 , and the second edge structure 1151 and the first electrode layer 1140 have an overlapping portion.

[0234] In this embodiment, the second edge structure 1151 includes a second edge surrounding layer (unmarked), located on the second side 1173, and the second edge surrounding layer is electrically connected to the second electrode layer 1180; and a second edge supporting layer (unmarked), located on the second side 1173, contacting the piezoelectric layer 1170, and located between the piezoelectric layer 1170 and the second edge surrounding layer, the second edge supporting layer is connected to the second electrode layer 1180, and the second edge surrounding layer and the second edge supporting layer overlap.

[0235] In this embodiment, the first edge structure 1150 is located outside the edge of part of the first electrode layer 1140, and the second edge structure 1151 is located outside the edge of part of the second electrode layer 1180. The first edge structure 1150 and the second edge structure 1151 have an overlapping portion to form a surrounding edge.

[0236] In this embodiment, the second composite structure 1190 is located outside the second edge structure 1151 and connected to the second edge structure 1151. The second composite structure 1190 includes: a second edge extension layer 1191, located on the second side 1173, electrically connected to the second edge structure 1151, and a second composite support layer 1193, located on the second side 1173, contacting the piezoelectric layer 1170, located between the piezoelectric layer 1170 and the second edge extension layer 1191, and connected to the second edge structure 1151. The second composite support layer 1193 overlaps with the second edge extension layer 1191, and the second edge extension layer 1191 and the second composite support layer 1193 have a second overlapping portion with the first electrode layer 1140.

[0237] In this embodiment, the width of the first overlapping portion is equal to the width of the first edge structure 1150 , and the width of the second overlapping portion is equal to the width of the second edge structure 1151 .

[0238] In this embodiment, the thickness of the second composite structure 1190 is greater than the thickness of the second edge structure 1151. In another embodiment, the thickness of the second composite structure on the second electrode layer side is equal to the thickness of the second edge structure on the second electrode layer side. In another embodiment, the thickness of the second composite structure on the second electrode layer side is less than the thickness of the second edge structure on the second electrode layer side.

[0239] In this embodiment, the first composite structure 1160 and the second composite structure 1190 have no overlapping portion. In this embodiment, the first composite structure 1160 and the second composite structure 1190 are located on both sides of the first electrode layer 1140 .

[0240] It should be noted that the first composite support layer 1163 thickens the medium between the second electrode layer 1180 and the first edge extension layer 1161, reducing the edge capacitance between the second electrode layer 1180 and the first edge extension layer 1161, and the second composite support layer 1193 thickens the medium between the first electrode layer 1140 and the second edge extension layer 1191, reducing the edge capacitance between the first electrode layer 1140 and the second edge extension layer 1191, thereby improving the electromechanical coupling coefficient of the resonant device.

[0241] In addition, the first edge structure 1150 and the first composite structure 1160 form a first reflective structure, which is located on the outside of the first electrode layer 1140; the second edge structure 1151 and the second composite structure 1190 form a second reflective structure, which is located on the outside of the second electrode layer 1180, thereby reflecting the sound waves in the resonance area, blocking leakage waves, and improving the Q value.

[0242] In this embodiment, removing the sacrificial layer 11110 includes: wet etching the sacrificial layer 11110 .

[0243] Figures 44 to 47 1 is a schematic structural diagram of each step of a method for forming a bulk acoustic wave resonator device 1200 according to an embodiment of the present invention.

[0244] like Figure 44 As shown, an embodiment of the present invention provides a method for forming a bulk acoustic wave resonator device 1200, including: providing a transition substrate 1280; forming a piezoelectric layer 1250 on the transition substrate 1280, wherein the piezoelectric layer 1250 includes a first side 1251 and a second side 1253 opposite to the first side 1251, and the transition substrate 1280 is located on the second side 1253; forming a first electrode layer 1240 on the first side 1251 of the piezoelectric layer 1250; and forming a sacrificial layer 1290 on the first side 1251 of the piezoelectric layer 1250, wherein the sacrificial layer 1290 covers a portion of the first electrode layer 1240.

[0245] like Figure 45 As shown, a first bonding layer (unmarked) is formed on the first side 1251 of the piezoelectric layer 1250, and the first bonding layer covers the sacrificial layer 1290 and the first electrode layer 1240; a substrate 1210 is provided; a second bonding layer (unmarked) is formed on one side of the substrate 1210; and the first bonding layer and the second bonding layer are bonded to form an intermediate layer 1220.

[0246] like Figure 46 and Figure 47 As shown, Figure 47 yes Figure 46 Schematic diagram of the cross-sectional structure A, after bonding, the transition substrate 1280 is removed; after removing the transition substrate 1280, a second electrode layer 1260 is formed on the second side 1253 of the piezoelectric layer 1250; a composite structure 1270 is formed on the second side 1253 of the piezoelectric layer 1250; after forming the composite structure 1270, the sacrificial layer 1290 is removed to form a cavity 1230, and the intermediate layer 1220 is embedded.

[0247] In this embodiment, the composite structure 1270 includes: an edge portion 1271, located on the second side 1253, the second electrode layer 1260 is located on the inner side of the edge portion 1271 (i.e., the side facing the central axis of the BAW resonator 1200), and the edge portion 1271 and the first electrode layer 1240 have an overlapping portion; an extension portion (not marked), located on the second side 1253, located on the outer side of the edge portion 1271 (i.e., the side facing the central axis of the BAW resonator 1200) and connected to the edge portion 1271; the extension portion includes an edge extension layer 1273, located on the second side 1253, electrically connected to the edge portion 1271, and a composite support layer 1275, located on the second side 1253, contacting the piezoelectric layer 1250, and located on the piezoelectric layer 1250 and the edge extension layer 1273, connecting the edge portion 1271, the composite support layer 1275 and the edge extension layer 1273 overlap, and the edge extension layer 1273 and the composite support layer 1275 have a first overlapping portion with the first electrode layer 1240; the extension portion also includes an edge extension layer 1277, located on the second side 1253, electrically connected to the edge portion 1271, and a composite support layer 1279, located on the second side 1253, contacting the piezoelectric layer 1250, located between the piezoelectric layer 1250 and the edge extension layer 1277, connecting the edge portion 1271, the composite support layer 1279 and the edge extension layer 1277 overlap, and the edge extension layer 1277 and the composite support layer 1279 have a second overlapping portion with the first electrode layer 1240,

[0248] In this embodiment, the edge portion 1271 includes an edge surrounding layer located on the second side 1253 and electrically connected to the second electrode layer 1260; and an edge supporting layer located on the second side 1253, between the piezoelectric layer 1250 and the edge surrounding layer, and connected to the second electrode layer 1260. The edge surrounding layer and the edge supporting layer overlap. In this embodiment, the thickness of the extension portion is equal to the thickness of the edge portion 1271.

[0249] In this embodiment, the thickness of the composite support layer 1275 is greater than the thickness of the edge support layer.

[0250] In another embodiment, the thickness of the first composite supporting layer of the extension portion is equal to the thickness of the edge supporting layer of the edge portion. In another embodiment, the thickness of the first composite supporting layer of the extension portion is less than the thickness of the edge supporting layer of the edge portion.

[0251] In this embodiment, the thickness of the composite support layer 1279 is greater than the thickness of the edge support layer.

[0252] In another embodiment, the thickness of the second composite supporting layer of the extension portion is equal to the thickness of the edge supporting layer of the edge portion. In another embodiment, the thickness of the second composite supporting layer of the extension portion is less than the thickness of the edge supporting layer of the edge portion.

[0253] In this embodiment, the edge extension layer 1273 and the edge extension layer 1277 have no overlapping portion. In this embodiment, the edge extension layer 1273 and the edge extension layer 1277 are located on both sides of the second electrode layer 1260.

[0254] In this embodiment, the width of the first overlapping portion is equal to the width of the edge portion 1271 , and the width of the second overlapping portion is equal to the width of the edge portion 1271 .

[0255] It should be noted that the composite support layer 1275 thickens the medium between the first electrode layer 1240 and the edge extension layer 1273, reducing the edge capacitance between the first electrode layer 1240 and the edge extension layer 1273, and the composite support layer 1279 thickens the medium between the first electrode layer 1240 and the edge extension layer 1277, reducing the edge capacitance between the first electrode layer 1240 and the edge extension layer 1277, thereby improving the electromechanical coupling coefficient of the resonant device.

[0256] In addition, the edge portion 1271 and the extension portion form a reflective structure, which is located outside the second electrode layer 1260, thereby reflecting the sound waves in the resonance region, blocking leakage waves, and improving the Q value.

[0257] In this embodiment, removing the sacrificial layer 1290 includes wet etching the sacrificial layer 1290 .

[0258] Figures 48 to 51 1 is a schematic structural diagram of each step of a method for forming a bulk acoustic wave resonator device 1300 according to an embodiment of the present invention.

[0259] like Figure 48 As shown, an embodiment of the present invention provides a method for forming a bulk acoustic wave resonator device 1300, including: providing a transition substrate 1380; forming a piezoelectric layer 1360 on the transition substrate 1380, the piezoelectric layer 1360 including a first side 1361 and a second side 1363 opposite to the first side 1361, the transition substrate 1380 being located on the second side 1363; forming a first electrode layer 1340 on the first side 1361 of the piezoelectric layer 1360; forming a composite structure 1350 on the first side 1361 of the piezoelectric layer 1360; and forming a sacrificial layer 1390 on the first side 1361 of the piezoelectric layer 1360, the sacrificial layer 1390 covering the first electrode layer 1340 and a portion of the composite structure 1350.

[0260] like Figure 49 As shown, a first bonding layer (unmarked) is formed on the first side 1361 of the piezoelectric layer 1360, and the first bonding layer covers the sacrificial layer 1390 and the composite structure 1350; a substrate 1310 is provided; a second bonding layer (unmarked) is formed on one side of the substrate 1310; and the first bonding layer and the second bonding layer are bonded to form an intermediate layer 1320.

[0261] like Figure 50 and Figure 51 As shown, Figure 51 yes Figure 50 Schematic diagram of the cross-sectional structure A, after bonding, the transition substrate 1380 is removed; after removing the transition substrate 1380, an electrode layer 1370 is formed on the second side 1363 of the piezoelectric layer 1360; after forming the electrode layer 1370, the sacrificial layer 1390 is removed to form a cavity 1330, and the intermediate layer 1320 is embedded.

[0262] In this embodiment, the composite structure 1350 includes: an edge portion 1351, located in the cavity 1330, the first electrode layer 1340 is located on the inner side of the edge portion 1351 (i.e., pointing to the side of the central axis of the BAW resonator 1300); an extension portion (not marked), located on the outer side of the edge portion 1351 (i.e., pointing to the side opposite to the central axis of the BAW resonator 1300), and the first end of the extension portion is located in the cavity 1330; wherein the extension portion includes an edge extension layer 1353, electrically connected to the edge portion 1351, and a composite support layer 1355, located between the edge extension layer 1353 and the piezoelectric layer 1360, connecting the edge portion 1351, and the composite support layer 1355 is connected to the edge portion 1351. The edge extension layer 1353 overlaps with the edge extension layer 1353; the extension portion also includes an edge extension layer 1357, which is located in the cavity 1330, electrically connected to the edge portion 1351, and a composite support layer 1359, contacts the piezoelectric layer 1360, is located between the edge extension layer 1357 and the piezoelectric layer 1360, is located in the cavity 1330, connects the edge portion 1351, and the composite support layer 1359 overlaps with the edge extension layer 1357; the edge portion 1351 has an overlapping portion with the electrode layer 1370, the edge extension layer 1353 and the composite support layer 1355 have a first overlapping portion with the electrode layer 1370, and the edge extension layer 1357 and the composite support layer 1359 have a second overlapping portion with the electrode layer 1370.

[0263] In this embodiment, the width of the first overlapping portion is equal to the width of the edge portion 1351 , and the width of the second overlapping portion is equal to the width of the edge portion 1351 .

[0264] In this embodiment, the edge portion 1351 includes an edge surrounding layer, which is located in the cavity 1330 and is electrically connected to the first electrode layer 1340; and an edge supporting layer, which is located in the cavity 1330 and contacts the piezoelectric layer 1360, and is located between the edge surrounding layer and the piezoelectric layer 1360, and is connected to the first electrode layer 1340, and the edge surrounding layer and the edge supporting layer overlap.

[0265] In this embodiment, the thickness of the extension portion is equal to the thickness of the edge portion 1351 .

[0266] In this embodiment, the thickness of the composite support layer 1355 is greater than the thickness of the edge support layer.

[0267] In another embodiment, the thickness of the first composite supporting layer of the extension portion is equal to the thickness of the edge supporting layer of the edge portion. In another embodiment, the thickness of the first composite supporting layer of the extension portion is less than the thickness of the edge supporting layer of the edge portion.

[0268] In this embodiment, the thickness of the composite support layer 1359 is greater than the thickness of the edge support layer.

[0269] In another embodiment, the thickness of the second composite supporting layer of the extension portion is equal to the thickness of the edge supporting layer of the edge portion. In another embodiment, the thickness of the second composite supporting layer of the extension portion is less than the thickness of the edge supporting layer of the edge portion.

[0270] In this embodiment, the edge extension layer 1353 and the edge extension layer 1357 have no overlapping portion. In this embodiment, the edge extension layer 1353 and the edge extension layer 1357 are located on both sides of the first electrode layer 1340.

[0271] It should be noted that the composite support layer 1355 thickens the medium between the electrode layer 1370 and the edge extension layer 1353, reducing the edge capacitance between the electrode layer 1370 and the edge extension layer 1353, and the composite support layer 1359 thickens the medium between the electrode layer 1370 and the edge extension layer 1357, reducing the edge capacitance between the electrode layer 1370 and the edge extension layer 1357, thereby improving the electromechanical coupling coefficient of the resonant device.

[0272] In addition, the edge portion 1351 and the extension portion form a reflective structure, which is located outside the first electrode layer 1340, thereby reflecting the sound waves in the resonance region, blocking leakage waves, and improving the Q value.

[0273] In this embodiment, removing the sacrificial layer 1390 includes wet etching the sacrificial layer 1390 .

[0274] Figures 52 to 55 14 is a schematic structural diagram of each step of a method for forming a bulk acoustic wave resonator device 1400 according to an embodiment of the present invention.

[0275] like Figure 52 As shown, an embodiment of the present invention provides a method for forming a bulk acoustic wave resonator device 1400, including: providing a transition substrate 1490; forming a piezoelectric layer 1460 on the transition substrate 1490, the piezoelectric layer 1460 including a first side 1461 and a second side 1463 opposite to the first side 1461, the transition substrate 1490 being located on the second side 1463; forming a first electrode layer 1440 on the first side 1461 of the piezoelectric layer 1460; forming a first composite structure 1450 on the first side 1461 of the piezoelectric layer 1460; and forming a sacrificial layer 14100 on the first side 1461 of the piezoelectric layer 1460, the sacrificial layer 14100 covering the first electrode layer 1440 and a portion of the first composite structure 1450.

[0276] like Figure 53 As shown, a first bonding layer (unmarked) is formed on the first side 1461 of the piezoelectric layer 1460, and the first bonding layer covers the sacrificial layer 14100 and the first composite structure 1450; a substrate 1410 is provided; a second bonding layer (unmarked) is formed on one side of the substrate 1410; and the first bonding layer and the second bonding layer are bonded to form an intermediate layer 1420.

[0277] like Figure 54 and Figure 55 As shown, Figure 55 yes Figure 54 Schematic diagram of the cross-sectional structure A, after bonding, the transition substrate 1490 is removed; after removing the transition substrate 1490, a second electrode layer 1470 is formed on the second side 1463 of the piezoelectric layer 1460; a second composite structure 1480 is formed on the second side 1463 of the piezoelectric layer 1460; after forming the second composite structure 1480, the sacrificial layer 14100 is removed to form a cavity 1430, which is embedded in the intermediate layer 1420.

[0278] In this embodiment, the first composite structure 1450 includes: a first edge portion 1451 located in the cavity 1430, and a first electrode layer 1440 located on the inner side of the first edge portion 1451 (i.e., facing the side of the central axis of the BAW resonator 1400); a first extension portion (unlabeled) located on the outer side of the first edge portion 1451 (i.e., facing the side opposite to the central axis of the BAW resonator 1400), with a first end of the first extension portion connected to the first edge portion 1451. The first extension portion includes a first edge extension layer 1453 electrically connected to the first edge portion 1451; and a first composite support layer 1455 located on the first side 1461, contacting the piezoelectric layer 1460, located between the piezoelectric layer 1460 and the first edge extension layer 1453, connecting the first edge portion 1451, and overlapping with the first edge extension layer 1453.

[0279] In this embodiment, the first edge portion 1451 includes a first edge surrounding layer (unmarked), located in the cavity 1130, and the first edge surrounding layer is electrically connected to the first electrode layer 1440; and a first edge supporting layer (unmarked), located in the cavity 1130, located on the first side 1461, contacting the piezoelectric layer 1460, located between the piezoelectric layer 1460 and the first edge surrounding layer, the first edge supporting layer is connected to the first electrode layer 1440, and the first edge surrounding layer and the first edge supporting layer overlap.

[0280] In this embodiment, the thickness of the first extension portion is equal to the thickness of the first edge portion 1451 .

[0281] In this embodiment, the thickness of the first composite support layer 1455 is greater than the thickness of the first edge support layer. In another embodiment, the thickness of the first composite support layer of the first extension portion is equal to the thickness of the first edge support layer of the first edge portion. In another embodiment, the thickness of the first composite support layer of the first extension portion is less than the thickness of the first edge support layer of the first edge portion.

[0282] In this embodiment, the second composite structure 1480 includes: a second edge portion 1481, located on the second side 1463, the second electrode layer 1470 is located on the inner side of the second edge portion 1481, and the second edge portion 1481 and the first electrode layer 1440 have an overlapping portion; a second extension portion (not marked), located on the second side 1463, located on the outer side of the second edge portion 1481 and connected to the second edge portion 1481, the second extension portion includes a second edge extension layer 1483, located on the second side 1463, electrically connected to the second edge portion 1481, and a second composite support layer 1485, located on the second side 1463, contacting the piezoelectric layer 1460, located between the piezoelectric layer 1460 and the second edge extension layer 1483, connecting the second edge portion 1481, the second composite support layer 1485 and the second edge extension layer 1483 overlap, and the second edge extension layer 1483 and the second composite support layer 1485 have a second overlapping portion with the first electrode layer 1440.

[0283] In this embodiment, the width of the first overlapping portion is equal to the width of the first edge portion 1451 , and the width of the second overlapping portion is equal to the width of the second edge portion 1481 .

[0284] In this embodiment, the second edge portion 1481 includes a second edge surrounding layer (unmarked), located on the second side 1463, and the second edge surrounding layer is electrically connected to the second electrode layer 1470; and a second edge supporting layer (unmarked), located on the second side 1463, located between the piezoelectric layer 1460 and the second edge surrounding layer, the second edge supporting layer is connected to the second electrode layer 1470, and the second edge surrounding layer and the second edge supporting layer overlap.

[0285] In this embodiment, the thickness of the second extension portion is equal to the thickness of the second edge portion 1481 .

[0286] In this embodiment, the first edge portion 1451 is located outside the edge of the first electrode layer 1440, and the second edge portion 1481 is located outside the edge of the second electrode layer 1470. The first edge portion 1451 and the second edge portion 1481 have an overlapping portion to form a surrounding edge.

[0287] In this embodiment, the thickness of the second composite support layer 1485 is greater than the thickness of the second edge support layer. In another embodiment, the thickness of the second composite support layer of the second extension portion is equal to the thickness of the second edge support layer of the second edge portion. In another embodiment, the thickness of the second composite support layer of the second extension portion is less than the thickness of the second edge support layer of the second edge portion.

[0288] In this embodiment, the first extension portion and the second extension portion have no overlapping portion. In this embodiment, the first extension portion and the second extension portion are located on both sides of the overlapping portion of the first electrode layer 1440 and the second electrode layer 1470 .

[0289] In this embodiment, the portion of the first electrode layer 1440 that overlaps with the second electrode layer 1470 is located in the cavity 1430 ; the portion of the electrode 1470 that overlaps with the electrode 1440 is located above the cavity 1430 , corresponding to the cavity 1430 .

[0290] It should be noted that the first composite support layer 1455 thickens the medium between the second electrode layer 1470 and the first edge extension layer 1453, reducing the edge capacitance between the second electrode layer 1470 and the first edge extension layer 1453, and the second composite support layer 1485 thickens the medium between the first electrode layer 1440 and the second edge extension layer 1483, reducing the edge capacitance between the first electrode layer 1440 and the second edge extension layer 1483, thereby improving the electromechanical coupling coefficient of the resonant device.

[0291] In addition, the first edge portion 1451 and the first extension portion form a first reflection structure, which is located on the outside of the first electrode layer 1440; the second edge portion 1481 and the second extension portion form a second reflection structure, which is located on the outside of the second electrode layer 1470, thereby reflecting the sound waves in the resonance area, blocking leakage waves, and improving the Q value.

[0292] In this embodiment, removing the sacrificial layer 14100 includes: wet etching the sacrificial layer 14100 .

[0293] like Figure 6As shown, an embodiment of the present invention provides a bulk acoustic wave resonator 300 comprising: a substrate 310; an intermediate layer 320, located on the substrate 310, wherein the upper surface side of the intermediate layer 320 comprises a cavity 330 and a groove 331, wherein the groove 331 is located on one side of the cavity 330 and communicates with the cavity 330, and the depth of the groove 331 is less than the depth of the cavity 330; a first electrode layer 340, wherein a first end 341 of the first electrode layer 340 is located in the cavity 330, and a second end 343 of the first electrode layer 340 is located in the groove 331, wherein the depth of the groove 331 is equal to the thickness of the first electrode layer 340; a piezoelectric layer 350, located on the first electrode layer 340 and the intermediate layer 320, covering the cavity 330, wherein the piezoelectric layer 350 comprises a first side 351 and a second side 353 opposite to the first side 351, the first electrode layer 340 and the intermediate layer 320 are located on the first side 351; the second electrode layer 360 is located on the second side 353 and is located on the piezoelectric layer 350; and a composite structure 370 is located on the second side 353, is located on the piezoelectric layer 350, and is connected to the second electrode layer 360, the composite structure 370 includes an edge extension layer 371, is located on the second side 353, is located above the piezoelectric layer 350, and is electrically connected to the second electrode layer 360, and a composite support layer 373, is located on the second side 353, is located on the piezoelectric layer 350, is located between the piezoelectric layer 350 and the edge extension layer 371, and is connected to the second electrode layer 360, and the composite support layer 373 overlaps with the edge extension layer 371.

[0294] It should be noted that the composite support layer 373 thickens the dielectric between the first electrode layer 340 and the edge extension layer 371, thereby reducing the edge capacitance 380 and improving the electromechanical coupling coefficient of the resonant device. Increasing the electromechanical coupling coefficient can increase the passband bandwidth of the filter device corresponding to the resonant device. In addition, see Figure 7 The acoustic impedance difference between the region C where the composite structure 370 is located and the region E where the second electrode layer 360 is located is greater than that in the case where there is no composite structure, thereby increasing the reflectivity of the edge transverse sound waves and improving the Q value. Figure 8 (i) An admittance curve 390 represents the normalized admittance value of a first BAW resonator without a composite structure, and an admittance curve 391 represents the normalized admittance value of a second BAW resonator including a composite structure. The bandwidth between the resonance and antiresonance of the admittance curve 391 is greater than the bandwidth between the resonance and antiresonance of the admittance curve 390; see Figure 8(ii), the quality factor curve 393 represents the normalized Q value of the first BAW resonator device, and the quality factor curve 395 represents the normalized Q value of the second BAW resonator device. It should be noted that, Figure 8 It is merely illustrative and is used to more intuitively understand the beneficial effects of the embodiments of the present invention, but is not equivalent to the actual performance of the BAW resonant device of the embodiments of the present invention.

[0295] In this embodiment, the material of the substrate 310 includes but is not limited to at least one of the following: silicon, silicon carbide, glass, gallium arsenide, gallium nitride, and ceramic.

[0296] In this embodiment, the material of the intermediate layer 320 includes, but is not limited to, at least one of the following: a polymer, an insulating dielectric, and polysilicon. In this embodiment, the polymer includes, but is not limited to, at least one of the following: benzocyclobutene (i.e., BCB), a photosensitive epoxy resin photoresist (e.g., SU-8), and polyimide. In this embodiment, the insulating dielectric includes, but is not limited to, at least one of the following: aluminum nitride, silicon dioxide, silicon nitride, and titanium oxide.

[0297] In this embodiment, the material of the first electrode layer 340 includes but is not limited to at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0298] In this embodiment, the piezoelectric layer 350 is a flat layer and also covers the upper surface of the intermediate layer 320. In this embodiment, the material of the piezoelectric layer 350 includes, but is not limited to, at least one of the following: aluminum nitride, aluminum nitride alloy, gallium nitride, zinc oxide, lithium tantalate, lithium niobate, lead zirconate titanate, or lead magnesium niobate-lead titanate.

[0299] In this embodiment, the piezoelectric layer 350 includes a plurality of crystal grains, and the plurality of crystal grains include a first crystal grain and a second crystal grain, wherein the first crystal grain and the second crystal grain are any two crystal grains in the plurality of crystal grains. Those skilled in the art know that the crystal orientation, crystal plane, etc. of the crystal grains can be represented based on a coordinate system. Figure 9 As shown in FIG, for hexagonal crystal grains, such as aluminum nitride crystal grains, the ac three-dimensional coordinate system (including the a-axis and the c-axis) is used to represent them. Figure 10 As shown, for grains of (i) orthorhombic system (a≠b≠c), (ii) tetragonal system (a=b≠c), (iii) cubic system (a=b=c), etc., an xyz coordinate system (including the x-axis, y-axis, and z-axis) is used for representation. In addition to the above two examples, grains can also be represented based on other coordinate systems known to those skilled in the art. Therefore, the present invention is not limited to the above two examples.

[0300] In this embodiment, the first grain can be represented based on a first three-dimensional coordinate system, and the second grain can be represented based on a second three-dimensional coordinate system, wherein the first three-dimensional coordinate system includes at least a first coordinate axis along the first direction and a third coordinate axis along the third direction, and the second three-dimensional coordinate system includes at least a second coordinate axis along the second direction and a fourth coordinate axis along the fourth direction, wherein the first coordinate axis corresponds to the height of the first grain, and the second coordinate axis corresponds to the height of the second grain.

[0301] In this embodiment, the first direction and the second direction are the same or opposite. It should be noted that the first direction and the second direction are the same means that the angle between the vector along the first direction and the vector along the second direction is within a range of 0 degrees to 5 degrees; the first direction and the second direction are opposite means that the angle between the vector along the first direction and the vector along the second direction is within a range of 175 degrees to 180 degrees.

[0302] In another embodiment, the first three-dimensional coordinate system is an ac three-dimensional coordinate system, wherein the first coordinate axis is the first c-axis and the third coordinate axis is the first a-axis; the second three-dimensional coordinate system is an ac three-dimensional coordinate system, wherein the second coordinate axis is the second c-axis and the fourth coordinate axis is the second a-axis, wherein the first c-axis and the second c-axis point in the same or opposite directions.

[0303] In another embodiment, the first three-dimensional coordinate system further includes a fifth coordinate axis along a fifth direction, and the second three-dimensional coordinate system further includes a sixth coordinate axis along a sixth direction. In another embodiment, the first direction and the second direction are the same or opposite, and the third direction and the fourth direction are the same or opposite. It should be noted that the third direction and the fourth direction are the same means that the angle between the vector along the third direction and the vector along the fourth direction ranges from 0 degrees to 5 degrees; the third direction and the fourth direction are opposite means that the angle between the vector along the third direction and the vector along the fourth direction ranges from 175 degrees to 180 degrees.

[0304] In another embodiment, the first 3D coordinate system is an xyz 3D coordinate system, wherein the first coordinate axis is the first z-axis, the third coordinate axis is the first y-axis, and the fifth coordinate axis is the first x-axis; and the second 3D coordinate system is an xyz 3D coordinate system, wherein the second coordinate axis is the second z-axis, the fourth coordinate axis is the second y-axis, and the sixth coordinate axis is the second x-axis. In another embodiment, the first z-axis and the second z-axis point in the same direction, and the first y-axis and the second y-axis point in the same direction. In another embodiment, the first z-axis and the second z-axis point in opposite directions, and the first y-axis and the second y-axis point in opposite directions. In another embodiment, the first z-axis and the second z-axis point in the same direction, and the first y-axis and the second y-axis point in opposite directions. In another embodiment, the first z-axis and the second z-axis point in the same direction, and the first y-axis and the second y-axis point in opposite directions. In another embodiment, the first z-axis and the second z-axis point in opposite directions, and the first y-axis and the second y-axis point in the same direction.

[0305] In this embodiment, the piezoelectric layer 350 includes a plurality of crystal grains, and the half-maximum width of the rocking curve of the crystal formed by the plurality of crystal grains is less than 2.5 degrees. It should be noted that the rocking curve describes the angular divergence of a specific crystal plane (the crystal plane determined by the diffraction angle) in the sample, and is represented by a plane coordinate system, wherein the horizontal axis is the angle between the crystal plane and the sample plane, and the vertical axis represents the diffraction intensity of the crystal plane at a certain angle. The rocking curve is used to indicate the quality of the crystal. The smaller the half-maximum width angle, the better the crystal quality. In addition, the full width at half maximum (FWHM) refers to the distance between the two points where the function value is equal to half of the peak value in a peak of the function.

[0306] It should be noted that forming the piezoelectric layer 350 on a plane can prevent the piezoelectric layer 350 from including grains with obvious turns, thereby improving the electromechanical coupling coefficient of the resonant device and the Q value of the resonant device.

[0307] In this embodiment, the material of the second electrode layer 360 includes but is not limited to at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0308] In this embodiment, the portion of the first electrode layer 340 that overlaps with the second electrode layer 360 is located in the cavity 330 ; the portion of the electrode 360 ​​that overlaps with the electrode 340 is located above the cavity 330 , corresponding to the cavity 330 .

[0309] In this embodiment, the material of the edge extension layer 371 includes metal. In this embodiment, the material of the edge extension layer 371 includes, but is not limited to, at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0310] In this embodiment, the medium of the composite support layer 373 includes a non-metallic material. In this embodiment, the medium of the composite support layer 373 includes, but is not limited to, at least one of the following: silicon dioxide, silicon oxycarbide, silicon oxyfluoride, and a polymer. The polymer includes, but is not limited to, at least one of the following: benzocyclobutene (i.e., BCB), a photosensitive epoxy resin photoresist (e.g., SU-8), and polyimide. In another embodiment, the medium of the composite support layer in the composite structure on the piezoelectric layer can be a vacuum, i.e., a vacuum layer. In another embodiment, the medium of the composite support layer in the composite structure on the piezoelectric layer can be air, i.e., an air layer.

[0311] In this embodiment, the composite structure 370 and the first electrode layer 340 have no overlapping portion.

[0312] Figure 5 FIG. 3 is a schematic top view of a bulk acoustic wave resonator device 300 according to an embodiment of the present invention.

[0313] like Figure 5 As shown, in this embodiment, the second electrode layer 360 is octagonal. It should be noted that electrode layers of other shapes known to those skilled in the art, such as hexagonal and pentagonal shapes, can also be applied to the embodiments of the present invention. In this embodiment, the composite structure 370 is adjacent to one side of the second electrode layer 360.

[0314] like Figure 14As shown, an embodiment of the present invention provides a bulk acoustic wave resonator 400 including: a substrate 410; an intermediate layer 420, located on the substrate 410, the upper surface side of the intermediate layer 420 including a cavity 430 and a groove 431, wherein the groove 431 is located on one side of the cavity 430 and communicates with the cavity 430, and the depth of the groove 431 is less than the depth of the cavity 430; a first electrode layer 440, located in the cavity 430; a composite structure 450, wherein a first end of the composite structure 450 is located in the cavity 430 and connected to the first electrode layer 440, and a second end of the composite structure 450 opposite to the first end is located in the groove 431, wherein the depth of the groove 431 is equal to the thickness of the composite structure 450 The composite structure 450 includes an edge extension layer 451, which is electrically connected to the first electrode layer 440, and a composite support layer 453, which is located on the edge extension layer 451 and connected to the first electrode layer 440, and the composite support layer 453 overlaps with the edge extension layer 451; a piezoelectric layer 460, which is located on the first electrode layer 440, the composite support layer 453 and the intermediate layer 420, and covers the cavity 430, wherein the piezoelectric layer 460 includes a first side 461 and a second side 463 opposite to the first side 461, and the first electrode layer 440, the composite structure 450 and the intermediate layer 420 are located on the first side 461; and a second electrode layer 470, which is located on the second side 463 and is located on the piezoelectric layer 460.

[0315] It should be noted that the composite support layer 453 thickens the medium between the second electrode layer 470 and the edge extension layer 451, thereby reducing the edge capacitance 480, improving the electromechanical coupling coefficient of the resonant device, and the composite structure 450 can block leakage waves and improve the Q value.

[0316] In this embodiment, the material of the substrate 410 includes but is not limited to at least one of the following: silicon, silicon carbide, glass, gallium arsenide, gallium nitride, and ceramic.

[0317] In this embodiment, the material of the intermediate layer 420 includes, but is not limited to, at least one of the following: a polymer, an insulating dielectric, and polysilicon. In this embodiment, the polymer includes, but is not limited to, at least one of the following: benzocyclobutene (i.e., BCB), a photosensitive epoxy resin photoresist (e.g., SU-8), and polyimide. In this embodiment, the insulating dielectric includes, but is not limited to, at least one of the following: aluminum nitride, silicon dioxide, silicon nitride, and titanium oxide.

[0318] In this embodiment, the material of the first electrode layer 440 includes but is not limited to at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0319] In this embodiment, the material of the edge extension layer 451 includes metal. In this embodiment, the material of the edge extension layer 451 includes, but is not limited to, at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0320] In this embodiment, the medium of the composite support layer 453 includes a non-metallic material. In this embodiment, the medium of the composite support layer 453 includes, but is not limited to, at least one of the following: silicon dioxide, silicon oxycarbide, silicon oxyfluoride, and a polymer. The polymer includes, but is not limited to, at least one of the following: benzocyclobutene (i.e., BCB), a photosensitive epoxy resin photoresist (e.g., SU-8), and polyimide. In another embodiment, the medium of the composite support layer in the composite structure below the piezoelectric layer can be a vacuum, i.e., a vacuum layer. In another embodiment, the medium of the composite support layer in the composite structure below the piezoelectric layer can be air, i.e., an air layer.

[0321] In this embodiment, the composite structure 450 and the second electrode layer 470 have no overlapping portion.

[0322] In this embodiment, the piezoelectric layer 460 is a flat layer and also covers the upper surface of the intermediate layer 420. In this embodiment, the material of the piezoelectric layer 460 includes, but is not limited to, at least one of the following: aluminum nitride, aluminum nitride alloy, gallium nitride, zinc oxide, lithium tantalate, lithium niobate, lead zirconate titanate, or lead magnesium niobate-lead titanate.

[0323] In this embodiment, the piezoelectric layer 460 includes a plurality of crystal grains, including a first crystal grain and a second crystal grain, wherein the first crystal grain and the second crystal grain are any two crystal grains of the plurality of crystal grains. Those skilled in the art will appreciate that crystal orientations, crystal planes, and the like of crystal grains can be represented based on a coordinate system.

[0324] In this embodiment, the first grain can be represented based on a first three-dimensional coordinate system, and the second grain can be represented based on a second three-dimensional coordinate system, wherein the first three-dimensional coordinate system includes at least a first coordinate axis along the first direction and a third coordinate axis along the third direction, and the second three-dimensional coordinate system includes at least a second coordinate axis along the second direction and a fourth coordinate axis along the fourth direction, wherein the first coordinate axis corresponds to the height of the first grain, and the second coordinate axis corresponds to the height of the second grain.

[0325] In this embodiment, the first direction and the second direction are the same or opposite. It should be noted that the first direction and the second direction are the same means that the angle between the vector along the first direction and the vector along the second direction is within a range of 0 degrees to 5 degrees; the first direction and the second direction are opposite means that the angle between the vector along the first direction and the vector along the second direction is within a range of 175 degrees to 180 degrees.

[0326] In another embodiment, the first three-dimensional coordinate system is an ac three-dimensional coordinate system, wherein the first coordinate axis is the first c-axis and the third coordinate axis is the first a-axis; the second three-dimensional coordinate system is an ac three-dimensional coordinate system, wherein the second coordinate axis is the second c-axis and the fourth coordinate axis is the second a-axis, wherein the first c-axis and the second c-axis point in the same or opposite directions.

[0327] In another embodiment, the first three-dimensional coordinate system further includes a fifth coordinate axis along a fifth direction, and the second three-dimensional coordinate system further includes a sixth coordinate axis along a sixth direction. In another embodiment, the first direction and the second direction are the same or opposite, and the third direction and the fourth direction are the same or opposite. It should be noted that the third direction and the fourth direction are the same means that the angle between the vector along the third direction and the vector along the fourth direction ranges from 0 degrees to 5 degrees; the third direction and the fourth direction are opposite means that the angle between the vector along the third direction and the vector along the fourth direction ranges from 175 degrees to 180 degrees.

[0328] In another embodiment, the first 3D coordinate system is an xyz 3D coordinate system, wherein the first coordinate axis is the first z-axis, the third coordinate axis is the first y-axis, and the fifth coordinate axis is the first x-axis; and the second 3D coordinate system is an xyz 3D coordinate system, wherein the second coordinate axis is the second z-axis, the fourth coordinate axis is the second y-axis, and the sixth coordinate axis is the second x-axis. In another embodiment, the first z-axis and the second z-axis point in the same direction, and the first y-axis and the second y-axis point in the same direction. In another embodiment, the first z-axis and the second z-axis point in opposite directions, and the first y-axis and the second y-axis point in opposite directions. In another embodiment, the first z-axis and the second z-axis point in the same direction, and the first y-axis and the second y-axis point in opposite directions. In another embodiment, the first z-axis and the second z-axis point in the same direction, and the first y-axis and the second y-axis point in opposite directions. In another embodiment, the first z-axis and the second z-axis point in opposite directions, and the first y-axis and the second y-axis point in the same direction.

[0329] In this embodiment, the piezoelectric layer 460 includes a plurality of crystal grains, and the half-maximum width of the rocking curve of the crystal formed by the plurality of crystal grains is less than 2.5 degrees.

[0330] It should be noted that forming the piezoelectric layer 460 on a plane can prevent the piezoelectric layer 460 from including grains with obvious turns, thereby improving the electromechanical coupling coefficient of the resonant device and the Q value of the resonant device.

[0331] In this embodiment, the material of the second electrode layer 470 includes but is not limited to at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0332] In this embodiment, the portion of the first electrode layer 440 that overlaps with the second electrode layer 470 is located in the cavity 430 ; the portion of the electrode 470 that overlaps with the electrode 440 is located above the cavity 430 , corresponding to the cavity 430 .

[0333] Figure 13 FIG4 is a schematic top view of a bulk acoustic wave resonator device 400 according to an embodiment of the present invention.

[0334] like Figure 13 As shown, in this embodiment, the first electrode layer 440 is octagonal. It should be noted that electrode layers of other shapes known to those skilled in the art, such as hexagonal and pentagonal shapes, can also be applied to the embodiments of the present invention. In this embodiment, the composite structure 450 is adjacent to two sides of the first electrode layer 440.

[0335] like Figure 18As shown, an embodiment of the present invention provides a bulk acoustic wave resonator 500 comprising: a substrate 510; an intermediate layer 520, located on the substrate 510, wherein the upper surface side of the intermediate layer 520 comprises a cavity 530 and a groove 531, wherein the groove 531 is located on one side of the cavity 530 and communicates with the cavity 530, and the depth of the groove 531 is less than the depth of the cavity 530; a first electrode layer 540, located in the cavity 530; a first composite structure 550, wherein the first end of the first composite structure 550 is located in the cavity 530 The first composite structure 550 is provided with a first edge extension layer 551 and a first composite support layer 553. The first composite support layer 553 is provided with a first edge extension layer 551 and a first composite support layer 553. The first composite support layer 553 is provided with a first edge extension layer 551 and a first composite support layer 553. The first composite support layer 553 is provided with a first edge extension layer 551 and a first composite support layer 553. The first composite support layer 553 is provided with a first edge extension layer 551. The piezoelectric layer 560 is located on the first electrode layer 540, the first composite support layer 553 and the intermediate layer 520, covering the cavity 530, wherein the piezoelectric layer 560 includes a first side 561 and a second side 563 opposite to the first side 561, the first electrode layer 540, the first composite structure 550 and the intermediate layer 520 are located on the first side 561; the second electrode layer 570 is located on the second side 563 and is located on the piezoelectric layer 560; and the second composite structure 580 is located on the second side 563 and is located on the piezoelectric layer 560. The second electrode layer 570 is connected on the piezoelectric layer 560. The second composite structure 580 includes a second edge extension layer 581, which is located on the second side 563, above the piezoelectric layer 560, and electrically connected to the second electrode layer 570, and a second composite support layer 583, which is located on the second side 563, on the piezoelectric layer 560, between the piezoelectric layer 560 and the second edge extension layer 581, and connected to the second electrode layer 570. The second composite support layer 583 overlaps with the second edge extension layer 581.

[0336] It should be noted that the first composite support layer 553 thickens the medium between the second electrode layer 570 and the first edge extension layer 551, reducing the edge capacitance 590, and the second composite support layer 583 thickens the medium between the first electrode layer 540 and the second edge extension layer 581, reducing the edge capacitance 591, thereby improving the electromechanical coupling coefficient of the resonant device and the first composite structure 550 can block leakage waves and improve the Q value.

[0337] In this embodiment, the material of the substrate 510 includes but is not limited to at least one of the following: silicon, silicon carbide, glass, gallium arsenide, gallium nitride, and ceramic.

[0338] In this embodiment, the material of the intermediate layer 520 includes, but is not limited to, at least one of the following: a polymer, an insulating dielectric, and polysilicon. In this embodiment, the polymer includes, but is not limited to, at least one of the following: benzocyclobutene (i.e., BCB), a photosensitive epoxy resin photoresist (e.g., SU-8), and polyimide. In this embodiment, the insulating dielectric includes, but is not limited to, at least one of the following: aluminum nitride, silicon dioxide, silicon nitride, and titanium oxide.

[0339] In this embodiment, the material of the first electrode layer 540 includes but is not limited to at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0340] In this embodiment, the material of the first edge extension layer 551 includes metal. In this embodiment, the material of the first edge extension layer 551 includes, but is not limited to, at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0341] In this embodiment, the medium of the first composite support layer 553 includes a non-metallic material. In this embodiment, the medium of the first composite support layer 553 includes, but is not limited to, at least one of the following: silicon dioxide, silicon oxycarbide, silicon oxyfluoride, and a polymer. The polymer includes, but is not limited to, at least one of the following: benzocyclobutene (i.e., BCB), a photosensitive epoxy resin photoresist (e.g., SU-8), and polyimide. In another embodiment, the medium of the composite support layer in the composite structure below the piezoelectric layer can be a vacuum, i.e., a vacuum layer. In another embodiment, the medium of the composite support layer in the composite structure below the piezoelectric layer can be air, i.e., an air layer.

[0342] In this embodiment, the piezoelectric layer 560 is a flat layer and also covers the upper surface of the intermediate layer 520. In this embodiment, the material of the piezoelectric layer 560 includes, but is not limited to, at least one of the following: aluminum nitride, aluminum nitride alloy, gallium nitride, zinc oxide, lithium tantalate, lithium niobate, lead zirconate titanate, or lead magnesium niobate-lead titanate.

[0343] In this embodiment, the piezoelectric layer 560 includes a plurality of crystal grains, including a first crystal grain and a second crystal grain, wherein the first crystal grain and the second crystal grain are any two crystal grains of the plurality of crystal grains. A person skilled in the art will appreciate that the crystal orientation, crystal plane, etc. of a crystal grain can be represented based on a coordinate system.

[0344] In this embodiment, the first grain can be represented based on a first three-dimensional coordinate system, and the second grain can be represented based on a second three-dimensional coordinate system, wherein the first three-dimensional coordinate system includes at least a first coordinate axis along the first direction and a third coordinate axis along the third direction, and the second three-dimensional coordinate system includes at least a second coordinate axis along the second direction and a fourth coordinate axis along the fourth direction, wherein the first coordinate axis corresponds to the height of the first grain, and the second coordinate axis corresponds to the height of the second grain.

[0345] In this embodiment, the first direction and the second direction are the same or opposite. It should be noted that the first direction and the second direction are the same means that the angle between the vector along the first direction and the vector along the second direction is within a range of 0 degrees to 5 degrees; the first direction and the second direction are opposite means that the angle between the vector along the first direction and the vector along the second direction is within a range of 175 degrees to 180 degrees.

[0346] In another embodiment, the first three-dimensional coordinate system is an ac three-dimensional coordinate system, wherein the first coordinate axis is the first c-axis and the third coordinate axis is the first a-axis; the second three-dimensional coordinate system is an ac three-dimensional coordinate system, wherein the second coordinate axis is the second c-axis and the fourth coordinate axis is the second a-axis, wherein the first c-axis and the second c-axis point in the same or opposite directions.

[0347] In another embodiment, the first three-dimensional coordinate system further includes a fifth coordinate axis along a fifth direction, and the second three-dimensional coordinate system further includes a sixth coordinate axis along a sixth direction. In another embodiment, the first direction and the second direction are the same or opposite, and the third direction and the fourth direction are the same or opposite. It should be noted that the third direction and the fourth direction are the same means that the angle between the vector along the third direction and the vector along the fourth direction ranges from 0 degrees to 5 degrees; the third direction and the fourth direction are opposite means that the angle between the vector along the third direction and the vector along the fourth direction ranges from 175 degrees to 180 degrees.

[0348] In another embodiment, the first 3D coordinate system is an xyz 3D coordinate system, wherein the first coordinate axis is the first z-axis, the third coordinate axis is the first y-axis, and the fifth coordinate axis is the first x-axis; and the second 3D coordinate system is an xyz 3D coordinate system, wherein the second coordinate axis is the second z-axis, the fourth coordinate axis is the second y-axis, and the sixth coordinate axis is the second x-axis. In another embodiment, the first z-axis and the second z-axis point in the same direction, and the first y-axis and the second y-axis point in the same direction. In another embodiment, the first z-axis and the second z-axis point in opposite directions, and the first y-axis and the second y-axis point in opposite directions. In another embodiment, the first z-axis and the second z-axis point in the same direction, and the first y-axis and the second y-axis point in opposite directions. In another embodiment, the first z-axis and the second z-axis point in the same direction, and the first y-axis and the second y-axis point in opposite directions. In another embodiment, the first z-axis and the second z-axis point in opposite directions, and the first y-axis and the second y-axis point in the same direction.

[0349] In this embodiment, the piezoelectric layer 560 includes a plurality of crystal grains, and the half-maximum width of the rocking curve of the crystal formed by the plurality of crystal grains is less than 2.5 degrees.

[0350] It should be noted that forming the piezoelectric layer 560 on a plane can prevent the piezoelectric layer 560 from including grains with obvious turns, thereby improving the electromechanical coupling coefficient of the resonant device and the Q value of the resonant device.

[0351] In this embodiment, the material of the second electrode layer 570 includes but is not limited to at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0352] In this embodiment, the portion of the first electrode layer 540 overlapping with the second electrode layer 570 is located in the cavity 530 ; the portion of the second electrode layer 570 overlapping with the first electrode layer 540 is located above the cavity 530 , corresponding to the cavity 530 .

[0353] In this embodiment, the material of the second edge extension layer 581 includes metal. In this embodiment, the material of the second edge extension layer 581 includes, but is not limited to, at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0354] In this embodiment, the medium of the second composite support layer 583 includes a non-metallic material. In this embodiment, the medium of the second composite support layer 583 includes, but is not limited to, at least one of the following: silicon dioxide, silicon oxycarbide, silicon oxyfluoride, and a polymer. The polymer includes, but is not limited to, at least one of the following: benzocyclobutene (i.e., BCB), a photosensitive epoxy resin photoresist (e.g., SU-8), and polyimide. In another embodiment, the medium of the composite support layer in the composite structure on the piezoelectric layer can be a vacuum, i.e., a vacuum layer. In another embodiment, the medium of the composite support layer in the composite structure on the piezoelectric layer can be air, i.e., an air layer.

[0355] In this embodiment, there is no overlap between the first composite structure 550 and the second composite structure 580. In this embodiment, the first composite structure 550 and the second composite structure 580 are located on both sides of the overlap between the first electrode layer 540 and the second electrode layer 570.

[0356] Figure 17 FIG. 5 is a schematic top view of a bulk acoustic wave resonator device 500 according to an embodiment of the present invention.

[0357] like Figure 17 As shown, in this embodiment, the first electrode layer 540 is octagonal. It should be noted that electrode layers of other shapes known to those skilled in the art, such as hexagons, pentagons, etc., can also be applied to embodiments of the present invention. In this embodiment, the first composite structure 550 is adjacent to one side of the first electrode layer 540. In this embodiment, the second electrode layer 570 is octagonal and overlaps with the first electrode layer 540. It should be noted that electrode layers of other shapes known to those skilled in the art, such as hexagons, pentagons, etc., can also be applied to embodiments of the present invention. In this embodiment, the second composite structure 580 is adjacent to three sides of the second electrode layer 570.

[0358] like Figure 22As shown, an embodiment of the present invention provides a bulk acoustic wave resonator 600 comprising: a substrate 610; an intermediate layer 620, located on the substrate 610, wherein the upper surface side of the intermediate layer 620 comprises a cavity 630 and a groove 631, wherein the groove 631 is located on one side of the cavity 630 and communicates with the cavity 630, and the depth of the groove 631 is less than the depth of the cavity 630; a first electrode layer 640, wherein the first end 641 of the first electrode layer 640 is located in the cavity 630, and the first electrode layer 640 is provided with a plurality of grooves 631 and a plurality of grooves 631. The second end 643 of the layer 640 is located in the groove 631, wherein the depth of the groove 631 is equal to the thickness of the first electrode layer 640; the piezoelectric layer 650 is located on the first electrode layer 640 and the intermediate layer 620, covering the cavity 630, wherein the piezoelectric layer 650 includes a first side 651 and a second side 653 opposite to the first side 651, the first electrode layer 640 and the intermediate layer 620 are located on the first side 651; the second electrode layer 660 is located on the second side 653 , located on the piezoelectric layer 650; an edge structure 670, located on the second side 653, located on the piezoelectric layer 650, the second electrode layer 660 is located on the inner side of the edge structure 670 (i.e., facing the side of the central axis of the BAW resonator 600), and the edge structure 670 and the first electrode layer 640 have an overlapping portion; and a composite structure 680, located on the second side 653, located on the piezoelectric layer 650, and located on the outer side of the edge structure 670 (i.e., facing the side of the central axis of the BAW resonator 600). The composite structure 680 is located on the opposite side of the central axis of 600) and connected to the edge structure 670, and includes an edge extension layer 681, which is located on the second side 653, is located above the piezoelectric layer 650, and is electrically connected to the edge structure 670, and a composite support layer 683, which is located on the second side 653, is located on the piezoelectric layer 650, is located between the piezoelectric layer 650 and the edge extension layer 681, and is connected to the edge structure 670, and the composite support layer 683 overlaps with the edge extension layer 681.

[0359] It should be noted that the composite support layer 683 thickens the dielectric between the first electrode layer 640 and the edge extension layer 681, thereby reducing the edge capacitance between the first electrode layer 640 and the edge extension layer 681 and improving the electromechanical coupling coefficient of the resonant device. Figure 23As shown, the acoustic impedance of the region F where the edge structure 670 is located is greater than that of the region E where the second electrode layer 660 is located, the acoustic impedance of the region F is greater than the acoustic impedance of air and vacuum, the acoustic impedance of the region F is greater than the acoustic impedance of the region C where the composite structure 680 is located, and the acoustic impedance of the region C is less than the acoustic impedance of the region E. The composite structure 680 can make the acoustic impedance of the region C closer to the acoustic impedance of air and vacuum, so that it can more effectively reflect the sound waves at the edge of the resonance area, block leakage waves, and improve the Q value.

[0360] In this embodiment, the material of the substrate 610 includes but is not limited to at least one of the following: silicon, silicon carbide, glass, gallium arsenide, gallium nitride, and ceramic.

[0361] In this embodiment, the material of the intermediate layer 620 includes, but is not limited to, at least one of the following: a polymer, an insulating dielectric, and polysilicon. In this embodiment, the polymer includes, but is not limited to, at least one of the following: benzocyclobutene (i.e., BCB), a photosensitive epoxy resin photoresist (e.g., SU-8), and polyimide. In this embodiment, the insulating dielectric includes, but is not limited to, at least one of the following: aluminum nitride, silicon dioxide, silicon nitride, and titanium oxide.

[0362] In this embodiment, the material of the first electrode layer 640 includes but is not limited to at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0363] In this embodiment, the piezoelectric layer 650 is a flat layer and also covers the upper surface of the intermediate layer 620. In this embodiment, the material of the piezoelectric layer 650 includes, but is not limited to, at least one of the following: aluminum nitride, aluminum nitride alloy, gallium nitride, zinc oxide, lithium tantalate, lithium niobate, lead zirconate titanate, or lead magnesium niobate-lead titanate.

[0364] In this embodiment, the piezoelectric layer 650 includes a plurality of crystal grains, including a first crystal grain and a second crystal grain, wherein the first crystal grain and the second crystal grain are any two crystal grains of the plurality of crystal grains. Those skilled in the art will appreciate that crystal orientations, crystal planes, and the like of crystal grains can be represented based on a coordinate system.

[0365] In this embodiment, the first grain can be represented based on a first three-dimensional coordinate system, and the second grain can be represented based on a second three-dimensional coordinate system, wherein the first three-dimensional coordinate system includes at least a first coordinate axis along the first direction and a third coordinate axis along the third direction, and the second three-dimensional coordinate system includes at least a second coordinate axis along the second direction and a fourth coordinate axis along the fourth direction, wherein the first coordinate axis corresponds to the height of the first grain, and the second coordinate axis corresponds to the height of the second grain.

[0366] In this embodiment, the first direction and the second direction are the same or opposite. It should be noted that the first direction and the second direction are the same means that the angle between the vector along the first direction and the vector along the second direction is within a range of 0 degrees to 5 degrees; the first direction and the second direction are opposite means that the angle between the vector along the first direction and the vector along the second direction is within a range of 175 degrees to 180 degrees.

[0367] In another embodiment, the first three-dimensional coordinate system is an ac three-dimensional coordinate system, wherein the first coordinate axis is the first c-axis and the third coordinate axis is the first a-axis; the second three-dimensional coordinate system is an ac three-dimensional coordinate system, wherein the second coordinate axis is the second c-axis and the fourth coordinate axis is the second a-axis, wherein the first c-axis and the second c-axis point in the same or opposite directions.

[0368] In another embodiment, the first three-dimensional coordinate system further includes a fifth coordinate axis along a fifth direction, and the second three-dimensional coordinate system further includes a sixth coordinate axis along a sixth direction. In another embodiment, the first direction and the second direction are the same or opposite, and the third direction and the fourth direction are the same or opposite. It should be noted that the third direction and the fourth direction are the same means that the angle between the vector along the third direction and the vector along the fourth direction ranges from 0 degrees to 5 degrees; the third direction and the fourth direction are opposite means that the angle between the vector along the third direction and the vector along the fourth direction ranges from 175 degrees to 180 degrees.

[0369] In another embodiment, the first 3D coordinate system is an xyz 3D coordinate system, wherein the first coordinate axis is the first z-axis, the third coordinate axis is the first y-axis, and the fifth coordinate axis is the first x-axis; and the second 3D coordinate system is an xyz 3D coordinate system, wherein the second coordinate axis is the second z-axis, the fourth coordinate axis is the second y-axis, and the sixth coordinate axis is the second x-axis. In another embodiment, the first z-axis and the second z-axis point in the same direction, and the first y-axis and the second y-axis point in the same direction. In another embodiment, the first z-axis and the second z-axis point in opposite directions, and the first y-axis and the second y-axis point in opposite directions. In another embodiment, the first z-axis and the second z-axis point in the same direction, and the first y-axis and the second y-axis point in opposite directions. In another embodiment, the first z-axis and the second z-axis point in the same direction, and the first y-axis and the second y-axis point in opposite directions. In another embodiment, the first z-axis and the second z-axis point in opposite directions, and the first y-axis and the second y-axis point in the same direction.

[0370] In this embodiment, the piezoelectric layer 650 includes a plurality of crystal grains, and the half-maximum width of the rocking curve of the crystal formed by the plurality of crystal grains is less than 2.5 degrees.

[0371] It should be noted that forming the piezoelectric layer 650 on a plane can prevent the piezoelectric layer 650 from including grains with obvious turns, thereby improving the electromechanical coupling coefficient of the resonant device and the Q value of the resonant device.

[0372] In this embodiment, the material of the second electrode layer 660 includes but is not limited to at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0373] In this embodiment, the portion of the first electrode layer 640 that overlaps with the second electrode layer 660 is located in the cavity 630 ; the portion of the electrode 660 that overlaps with the electrode 640 is located above the cavity 630 and corresponds to the cavity 630 .

[0374] In this embodiment, the edge structure 670 includes an edge surrounding layer, which is located on the second side 653 and above the piezoelectric layer 650, and the edge surrounding layer is electrically connected to the second electrode layer 660; and an edge supporting layer, which is located on the second side 653, on the piezoelectric layer 650, between the piezoelectric layer 650 and the edge surrounding layer, and the edge supporting layer is connected to the second electrode layer 660, and the edge surrounding layer and the edge supporting layer overlap.

[0375] In this embodiment, the material of the edge surrounding layer is different from the material of the edge supporting layer. In another embodiment, the material of the edge surrounding layer is the same as the material of the edge supporting layer.

[0376] In this embodiment, the material of the edge surrounding layer comprises metal, and the material of the edge support layer comprises a non-metallic material. In another embodiment, the material of the edge surrounding layer comprises metal, and the medium of the edge support layer comprises air, i.e., an air layer. In another embodiment, the material of the edge surrounding layer comprises metal, and the medium of the edge support layer comprises vacuum, i.e., a vacuum layer. In another embodiment, the material of the edge surrounding layer comprises metal, and the material of the edge support layer comprises metal.

[0377] In this embodiment, the thickness of the composite structure 680 is greater than the thickness of the edge structure 670. In another embodiment, the thickness of the composite structure on the piezoelectric layer is equal to the thickness of the edge structure on the piezoelectric layer. In another embodiment, the thickness of the composite structure on the piezoelectric layer is less than the thickness of the edge structure on the piezoelectric layer.

[0378] In this embodiment, the material of the edge extension layer 681 includes metal. In this embodiment, the material of the edge extension layer 681 includes, but is not limited to, at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0379] In this embodiment, the medium of the composite support layer 683 includes a non-metallic material. In this embodiment, the medium of the composite support layer 683 includes, but is not limited to, at least one of the following: silicon dioxide, silicon oxycarbide, silicon oxyfluoride, and a polymer. The polymer includes, but is not limited to, at least one of the following: benzocyclobutene (i.e., BCB), a photosensitive epoxy resin photoresist (e.g., SU-8), and polyimide. In another embodiment, the medium of the composite support layer in the composite structure on the piezoelectric layer can be a vacuum, i.e., a vacuum layer. In another embodiment, the medium of the composite support layer in the composite structure on the piezoelectric layer can be air, i.e., an air layer.

[0380] In this embodiment, the composite structure 680 and the first electrode layer 640 have no overlapping portion.

[0381] Figure 21 FIG. 6 is a schematic top view of a bulk acoustic wave resonator device 600 according to an embodiment of the present invention.

[0382] like Figure 21 As shown, in this embodiment, the edge structure 670 is annular. In this embodiment, the edge structure 670 is octagonal. It should be noted that other edge structures known to those skilled in the art, such as hexagonal, pentagonal, etc., can also be applied to the embodiments of the present invention. In this embodiment, the composite structure 680 is adjacent to one side of the edge structure 670.

[0383] like Figure 27As shown, an embodiment of the present invention provides a bulk acoustic wave resonator device 700 comprising: a substrate 710; an intermediate layer 720, located on the substrate 710, wherein the upper surface side of the intermediate layer 720 comprises a cavity 730 and a groove 731, wherein the groove 731 is located on one side of the cavity 730 and communicates with the cavity 730, and the depth of the groove 731 is less than the depth of the cavity 730; a first electrode layer 740, located in the cavity 730; an edge structure 750, located in the cavity 730, wherein the first electrode layer 740 is located on the inner side of the edge structure 750 (i.e., pointing to the side of the central axis of the bulk acoustic wave resonator 700); a composite structure 760, located on the outer side of the edge structure 750 (i.e., pointing to the side opposite to the central axis of the bulk acoustic wave resonator 700), wherein a first end of the composite structure 760 is connected to the edge structure 750, and a second end of the composite structure 760, opposite to the first end, is located in the groove 731. , wherein the depth of the groove 731 is equal to the thickness of the composite structure 760, and the composite structure 760 includes an edge extension layer 761, which is electrically connected to the edge structure 750, and a composite support layer 763, which is located on the edge extension layer 761 and connected to the edge structure 750, and the composite support layer 763 overlaps with the edge extension layer 761; a piezoelectric layer 770, which is located on the first electrode layer 740, the edge structure 750, the composite support layer 763 and the intermediate layer 720, and covers the cavity 730, wherein the piezoelectric layer 770 includes a first side 771 and a second side 773 opposite to the first side 771, and the first electrode layer 740, the edge structure 750, the composite structure 760 and the intermediate layer 720 are located on the first side 771; a second electrode layer 780, which is located on the second side 773, is located on the piezoelectric layer 770, and the edge structure 750 and the second electrode layer 780 have an overlapping portion.

[0384] It should be noted that the composite support layer 763 thickens the medium between the second electrode layer 780 and the edge extension layer 761, thereby reducing the edge capacitance between the second electrode layer 780 and the edge extension layer 761, and improving the electromechanical coupling coefficient of the resonant device. In addition, the acoustic impedance of the edge region where the edge structure 750 is located is greater than the acoustic impedance of the inner region where the first electrode layer 740 is located, the acoustic impedance of the edge region is greater than the acoustic impedance of air and vacuum, the acoustic impedance of the edge region is greater than the acoustic impedance of the outer region where the composite structure 760 is located, and the acoustic impedance of the outer region is less than the acoustic impedance of the inner region. The composite structure 760 can make the acoustic impedance of the outer region closer to the acoustic impedance of air and vacuum, thereby more effectively reflecting the sound waves at the edge of the resonance region, blocking leakage waves, and improving the Q value.

[0385] In this embodiment, the material of the substrate 710 includes but is not limited to at least one of the following: silicon, silicon carbide, glass, gallium arsenide, gallium nitride, and ceramic.

[0386] In this embodiment, the material of the intermediate layer 720 includes, but is not limited to, at least one of the following: a polymer, an insulating dielectric, and polysilicon. In this embodiment, the polymer includes, but is not limited to, at least one of the following: benzocyclobutene (i.e., BCB), a photosensitive epoxy resin photoresist (e.g., SU-8), and polyimide. In this embodiment, the insulating dielectric includes, but is not limited to, at least one of the following: aluminum nitride, silicon dioxide, silicon nitride, and titanium oxide.

[0387] In this embodiment, the material of the first electrode layer 740 includes but is not limited to at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0388] In this embodiment, the edge structure 750 includes an edge surrounding layer, which is located in the cavity 730 and is electrically connected to the first electrode layer 740; and an edge supporting layer, which is located on the edge surrounding layer and is connected to the first electrode layer 740, and the edge surrounding layer and the edge supporting layer overlap.

[0389] In this embodiment, the material of the edge surrounding layer is different from the material of the edge supporting layer. In another embodiment, the material of the edge surrounding layer is the same as the material of the edge supporting layer.

[0390] In this embodiment, the material of the edge surrounding layer comprises metal, and the material of the edge support layer comprises a non-metallic material. In another embodiment, the material of the edge surrounding layer comprises metal, and the medium of the edge support layer comprises air, i.e., an air layer. In another embodiment, the material of the edge surrounding layer comprises metal, and the medium of the edge support layer comprises vacuum, i.e., a vacuum layer. In another embodiment, the material of the edge surrounding layer comprises metal, and the material of the edge support layer comprises metal.

[0391] In this embodiment, the thickness of the composite structure 760 is greater than the thickness of the edge structure 750. In another embodiment, the thickness of the composite structure below the piezoelectric layer is equal to the thickness of the edge structure below the piezoelectric layer. In another embodiment, the thickness of the composite structure below the piezoelectric layer is less than the thickness of the edge structure below the piezoelectric layer.

[0392] In this embodiment, the material of the edge extension layer 761 includes metal. In this embodiment, the material of the edge extension layer 761 includes, but is not limited to, at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0393] In this embodiment, the medium of the composite support layer 763 includes a non-metallic material. In this embodiment, the medium of the composite support layer 763 includes, but is not limited to, at least one of the following: silicon dioxide, silicon oxycarbide, silicon oxyfluoride, and a polymer. The polymer includes, but is not limited to, at least one of the following: benzocyclobutene (i.e., BCB), a photosensitive epoxy resin photoresist (e.g., SU-8), and polyimide. In another embodiment, the medium of the composite support layer in the composite structure below the piezoelectric layer can be a vacuum, i.e., a vacuum layer. In another embodiment, the medium of the composite support layer in the composite structure below the piezoelectric layer can be air, i.e., an air layer.

[0394] In this embodiment, the composite structure 760 and the second electrode layer 780 have no overlapping portion.

[0395] In this embodiment, the piezoelectric layer 770 is a flat layer and also covers the upper surface of the intermediate layer 720. In this embodiment, the material of the piezoelectric layer 770 includes, but is not limited to, at least one of the following: aluminum nitride, aluminum nitride alloy, gallium nitride, zinc oxide, lithium tantalate, lithium niobate, lead zirconate titanate, or lead magnesium niobate-lead titanate.

[0396] In this embodiment, the piezoelectric layer 770 includes a plurality of crystal grains, including a first crystal grain and a second crystal grain, wherein the first crystal grain and the second crystal grain are any two crystal grains of the plurality of crystal grains. A person skilled in the art will appreciate that the crystal orientation, crystal plane, etc. of a crystal grain can be represented based on a coordinate system.

[0397] In this embodiment, the first grain can be represented based on a first three-dimensional coordinate system, and the second grain can be represented based on a second three-dimensional coordinate system, wherein the first three-dimensional coordinate system includes at least a first coordinate axis along the first direction and a third coordinate axis along the third direction, and the second three-dimensional coordinate system includes at least a second coordinate axis along the second direction and a fourth coordinate axis along the fourth direction, wherein the first coordinate axis corresponds to the height of the first grain, and the second coordinate axis corresponds to the height of the second grain.

[0398] In this embodiment, the first direction and the second direction are the same or opposite. It should be noted that the first direction and the second direction are the same means that the angle between the vector along the first direction and the vector along the second direction is within a range of 0 degrees to 5 degrees; the first direction and the second direction are opposite means that the angle between the vector along the first direction and the vector along the second direction is within a range of 175 degrees to 180 degrees.

[0399] In another embodiment, the first three-dimensional coordinate system is an ac three-dimensional coordinate system, wherein the first coordinate axis is the first c-axis and the third coordinate axis is the first a-axis; the second three-dimensional coordinate system is an ac three-dimensional coordinate system, wherein the second coordinate axis is the second c-axis and the fourth coordinate axis is the second a-axis, wherein the first c-axis and the second c-axis point in the same or opposite directions.

[0400] In another embodiment, the first three-dimensional coordinate system further includes a fifth coordinate axis along a fifth direction, and the second three-dimensional coordinate system further includes a sixth coordinate axis along a sixth direction. In another embodiment, the first direction and the second direction are the same or opposite, and the third direction and the fourth direction are the same or opposite. It should be noted that the third direction and the fourth direction are the same means that the angle between the vector along the third direction and the vector along the fourth direction ranges from 0 degrees to 5 degrees; the third direction and the fourth direction are opposite means that the angle between the vector along the third direction and the vector along the fourth direction ranges from 175 degrees to 180 degrees.

[0401] In another embodiment, the first 3D coordinate system is an xyz 3D coordinate system, wherein the first coordinate axis is the first z-axis, the third coordinate axis is the first y-axis, and the fifth coordinate axis is the first x-axis; and the second 3D coordinate system is an xyz 3D coordinate system, wherein the second coordinate axis is the second z-axis, the fourth coordinate axis is the second y-axis, and the sixth coordinate axis is the second x-axis. In another embodiment, the first z-axis and the second z-axis point in the same direction, and the first y-axis and the second y-axis point in the same direction. In another embodiment, the first z-axis and the second z-axis point in opposite directions, and the first y-axis and the second y-axis point in opposite directions. In another embodiment, the first z-axis and the second z-axis point in the same direction, and the first y-axis and the second y-axis point in opposite directions. In another embodiment, the first z-axis and the second z-axis point in the same direction, and the first y-axis and the second y-axis point in opposite directions. In another embodiment, the first z-axis and the second z-axis point in opposite directions, and the first y-axis and the second y-axis point in the same direction.

[0402] In this embodiment, the piezoelectric layer 770 includes a plurality of crystal grains, and the half-peak width of the rocking curve of the crystal formed by the plurality of crystal grains is less than 2.5 degrees.

[0403] It should be noted that forming the piezoelectric layer 770 on a plane can ensure that the piezoelectric layer 770 does not include grains with obvious turns, thereby improving the electromechanical coupling coefficient of the resonant device and the Q value of the resonant device.

[0404] In this embodiment, the material of the second electrode layer 780 includes but is not limited to at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0405] In this embodiment, the portion of the first electrode layer 740 that overlaps with the second electrode layer 780 is located in the cavity 730 ; the portion of the electrode 780 that overlaps with the electrode 740 is located above the cavity 730 , corresponding to the cavity 730 .

[0406] Figure 26 FIG. 7 is a schematic top view of a bulk acoustic wave resonator device 700 according to an embodiment of the present invention.

[0407] like Figure 26 As shown, in this embodiment, the edge structure 750 is annular. In this embodiment, the edge structure 750 is octagonal. It should be noted that other edge structures known to those skilled in the art, such as hexagonal, pentagonal, etc., can also be applied to the embodiments of the present invention. In this embodiment, the composite structure 760 is adjacent to three sides of the edge structure 750.

[0408] like Figure 31As shown, an embodiment of the present invention provides a bulk acoustic wave resonator 800 comprising: a substrate 810; an intermediate layer 820, located on the substrate 810, wherein the upper surface side of the intermediate layer 820 comprises a cavity 830 and a groove 831, wherein the groove 831 is located on one side of the cavity 830 and communicates with the cavity 830, and the depth of the groove 831 is less than the depth of the cavity 830; a first electrode layer 840, located in the cavity 830; a first edge structure 850, located in the cavity 830, and the first electrode layer 840 is located on the inner side of the first edge structure 850 (i.e., , pointing to one side of the central axis of the BAW resonator 800); a first composite structure 860, located outside the first edge structure 850 (i.e., pointing to the side opposite to the central axis of the BAW resonator 800), a first end of the first composite structure 860 is connected to the first edge structure 850, a second end of the first composite structure 860 opposite to the first end is located in the groove 831, wherein the depth of the groove 831 is equal to the thickness of the first composite structure 860, and the first composite structure 860 includes a first edge extension layer 861, electrically connected to the first edge The edge structure 850 and the first composite support layer 863 are located on the first edge extension layer 861 and connected to the first edge structure 850. The first composite support layer 863 overlaps with the first edge extension layer 861. The piezoelectric layer 870 is located on the first electrode layer 840, the first edge structure 850, the first composite support layer 863 and the intermediate layer 820, covering the cavity 830. The piezoelectric layer 870 includes a first side 871 and a second side 873 opposite to the first side 871. The first electrode layer 840, the first edge structure 850 and the intermediate layer 820 are connected to the first composite support layer 863. The first composite structure 860 and the intermediate layer 820 are located on the first side 871; the second electrode layer 880 is located on the second side 873 and on the piezoelectric layer 870, and the second electrode layer 880 and the first edge structure 850 have an overlapping portion; the second edge structure 851 is located on the second side 873 and on the piezoelectric layer 870, and the second electrode layer 880 is located on the inner side of the second edge structure 851 (i.e., the side facing the central axis of the BAW resonator 800), and the second edge structure 851 and the first electrode layer 840 have an overlapping portion;A second composite structure 890 is located on the second side 873, on the piezoelectric layer 870, and outside the second edge structure 851 (i.e., facing the side opposite the central axis of the BAW resonator 800) and connected to the second edge structure 851. The second composite structure 890 includes a second edge extension layer 891 located on the second side 873, above the piezoelectric layer 870, and electrically connected to the second edge structure 851. A second composite support layer 893 is located on the second side 873, on the piezoelectric layer 870, between the piezoelectric layer 870 and the second edge extension layer 891, and connected to the second edge structure 851. The second composite support layer 893 overlaps with the second edge extension layer 891.

[0409] It should be noted that the first composite support layer 863 thickens the medium between the second electrode layer 880 and the first edge extension layer 861, reducing the edge capacitance between the second electrode layer 880 and the first edge extension layer 861, and the second composite support layer 893 thickens the medium between the first electrode layer 840 and the second edge extension layer 891, reducing the edge capacitance between the first electrode layer 840 and the second edge extension layer 891, thereby improving the electromechanical coupling coefficient of the resonant device.

[0410] In addition, the acoustic impedance of the first edge region where the first edge structure 850 is located is greater than that of the inner region where the first electrode layer 840 is located, and the acoustic impedance of the first edge region is greater than that of the first outer region where the first composite structure 860 is located, and the acoustic impedance of the first outer region is smaller than that of the inner region. The first composite structure 860 can make the acoustic impedance of the first outer region closer to the acoustic impedance of air and vacuum; the acoustic impedance of the second edge region where the second edge structure 851 is located is greater than that of the inner region where the second electrode layer 880 is located, and the acoustic impedance of the second edge region is greater than that of the second outer region where the second composite structure 890 is located, and the acoustic impedance of the second outer region is smaller than that of the inner region. The second composite structure 890 can make the acoustic impedance of the second outer region closer to the acoustic impedance of air and vacuum; thereby, the sound waves at the edge of the resonance zone can be more effectively reflected, leakage waves can be blocked, and the Q value can be improved.

[0411] In this embodiment, the material of the substrate 810 includes but is not limited to at least one of the following: silicon, silicon carbide, glass, gallium arsenide, gallium nitride, and ceramics.

[0412] In this embodiment, the material of the intermediate layer 820 includes, but is not limited to, at least one of the following: a polymer, an insulating dielectric, and polysilicon. In this embodiment, the polymer includes, but is not limited to, at least one of the following: benzocyclobutene (i.e., BCB), a photosensitive epoxy resin photoresist (e.g., SU-8), and polyimide. In this embodiment, the insulating dielectric includes, but is not limited to, at least one of the following: aluminum nitride, silicon dioxide, silicon nitride, and titanium oxide.

[0413] In this embodiment, the material of the first electrode layer 840 includes but is not limited to at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0414] In this embodiment, the first edge structure 850 includes a first edge surrounding layer, which is located in the cavity 830 and is electrically connected to the first electrode layer 840; and a first edge supporting layer, which is located on the first edge surrounding layer and is connected to the first electrode layer 840, and the first edge surrounding layer and the first edge supporting layer overlap.

[0415] In this embodiment, the material of the first edge surrounding layer is different from the material of the first edge supporting layer. In another embodiment, the material of the first edge surrounding layer is the same as the material of the first edge supporting layer.

[0416] In this embodiment, the material of the first edge surrounding layer comprises metal, and the material of the first edge supporting layer comprises a non-metallic material. In another embodiment, the material of the first edge surrounding layer comprises metal, and the medium of the first edge supporting layer comprises air, i.e., an air layer. In another embodiment, the material of the first edge surrounding layer comprises metal, and the medium of the first edge supporting layer comprises vacuum, i.e., a vacuum layer. In another embodiment, the material of the first edge surrounding layer comprises metal, and the material of the first edge supporting layer comprises metal.

[0417] In this embodiment, the thickness of the first composite structure 860 is greater than the thickness of the first edge structure 850. In another embodiment, the thickness of the composite structure below the piezoelectric layer is equal to the thickness of the edge structure below the piezoelectric layer. In another embodiment, the thickness of the composite structure below the piezoelectric layer is less than the thickness of the edge structure below the piezoelectric layer.

[0418] In this embodiment, the material of the first edge extension layer 861 includes metal. In this embodiment, the material of the first edge extension layer 861 includes, but is not limited to, at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0419] In this embodiment, the medium of the first composite support layer 863 includes a non-metallic material. In this embodiment, the medium of the first composite support layer 863 includes, but is not limited to, at least one of the following: silicon dioxide, silicon oxycarbide, silicon oxyfluoride, and a polymer. The polymer includes, but is not limited to, at least one of the following: benzocyclobutene (i.e., BCB), a photosensitive epoxy resin photoresist (e.g., SU-8), and polyimide. In another embodiment, the medium of the composite support layer in the composite structure below the piezoelectric layer can be a vacuum, i.e., a vacuum layer. In another embodiment, the medium of the composite support layer in the composite structure below the piezoelectric layer can be air, i.e., an air layer.

[0420] In this embodiment, the first composite structure 860 and the second electrode layer 880 have no overlapping portion.

[0421] In this embodiment, the piezoelectric layer 870 is a flat layer and also covers the upper surface of the intermediate layer 820. In this embodiment, the material of the piezoelectric layer 870 includes, but is not limited to, at least one of the following: aluminum nitride, aluminum nitride alloy, gallium nitride, zinc oxide, lithium tantalate, lithium niobate, lead zirconate titanate, or lead magnesium niobate-lead titanate.

[0422] In this embodiment, the piezoelectric layer 870 includes a plurality of crystal grains, including a first crystal grain and a second crystal grain, wherein the first crystal grain and the second crystal grain are any two crystal grains of the plurality of crystal grains. Those skilled in the art will appreciate that crystal orientations, crystal planes, and the like of crystal grains can be represented based on a coordinate system.

[0423] In this embodiment, the first grain can be represented based on a first three-dimensional coordinate system, and the second grain can be represented based on a second three-dimensional coordinate system, wherein the first three-dimensional coordinate system includes at least a first coordinate axis along the first direction and a third coordinate axis along the third direction, and the second three-dimensional coordinate system includes at least a second coordinate axis along the second direction and a fourth coordinate axis along the fourth direction, wherein the first coordinate axis corresponds to the height of the first grain, and the second coordinate axis corresponds to the height of the second grain.

[0424] In this embodiment, the first direction and the second direction are the same or opposite. It should be noted that the first direction and the second direction are the same means that the angle between the vector along the first direction and the vector along the second direction is within a range of 0 degrees to 5 degrees; the first direction and the second direction are opposite means that the angle between the vector along the first direction and the vector along the second direction is within a range of 175 degrees to 180 degrees.

[0425] In another embodiment, the first three-dimensional coordinate system is an ac three-dimensional coordinate system, wherein the first coordinate axis is the first c-axis and the third coordinate axis is the first a-axis; the second three-dimensional coordinate system is an ac three-dimensional coordinate system, wherein the second coordinate axis is the second c-axis and the fourth coordinate axis is the second a-axis, wherein the first c-axis and the second c-axis point in the same or opposite directions.

[0426] In another embodiment, the first three-dimensional coordinate system further includes a fifth coordinate axis along a fifth direction, and the second three-dimensional coordinate system further includes a sixth coordinate axis along a sixth direction. In another embodiment, the first direction and the second direction are the same or opposite, and the third direction and the fourth direction are the same or opposite. It should be noted that the third direction and the fourth direction are the same means that the angle between the vector along the third direction and the vector along the fourth direction ranges from 0 degrees to 5 degrees; the third direction and the fourth direction are opposite means that the angle between the vector along the third direction and the vector along the fourth direction ranges from 175 degrees to 180 degrees.

[0427] In another embodiment, the first 3D coordinate system is an xyz 3D coordinate system, wherein the first coordinate axis is the first z-axis, the third coordinate axis is the first y-axis, and the fifth coordinate axis is the first x-axis; and the second 3D coordinate system is an xyz 3D coordinate system, wherein the second coordinate axis is the second z-axis, the fourth coordinate axis is the second y-axis, and the sixth coordinate axis is the second x-axis. In another embodiment, the first z-axis and the second z-axis point in the same direction, and the first y-axis and the second y-axis point in the same direction. In another embodiment, the first z-axis and the second z-axis point in opposite directions, and the first y-axis and the second y-axis point in opposite directions. In another embodiment, the first z-axis and the second z-axis point in the same direction, and the first y-axis and the second y-axis point in opposite directions. In another embodiment, the first z-axis and the second z-axis point in the same direction, and the first y-axis and the second y-axis point in opposite directions. In another embodiment, the first z-axis and the second z-axis point in opposite directions, and the first y-axis and the second y-axis point in the same direction.

[0428] In this embodiment, the piezoelectric layer 870 includes a plurality of crystal grains, and the half-peak width of the rocking curve of the crystal formed by the plurality of crystal grains is less than 2.5 degrees.

[0429] It should be noted that forming the piezoelectric layer 870 on a plane can ensure that the piezoelectric layer 870 does not include grains with obvious turns, thereby improving the electromechanical coupling coefficient of the resonant device and the Q value of the resonant device.

[0430] In this embodiment, the material of the second electrode layer 880 includes but is not limited to at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0431] In this embodiment, the portion of the first electrode layer 840 that overlaps with the second electrode layer 880 is located in the cavity 830 ; the portion of the electrode 880 that overlaps with the electrode 840 is located above the cavity 830 and corresponds to the cavity 830 .

[0432] In this embodiment, the second edge structure 851 includes a second edge surrounding layer, located on the second side 873, above the piezoelectric layer 870, and the second edge surrounding layer is electrically connected to the second electrode layer 880; and a second edge supporting layer, located on the second side 873, on the piezoelectric layer 870, between the piezoelectric layer 870 and the second edge surrounding layer, the second edge supporting layer is connected to the second electrode layer 880, and the second edge surrounding layer and the second edge supporting layer overlap.

[0433] In this embodiment, the material of the second edge surrounding layer is different from the material of the second edge supporting layer. In another embodiment, the material of the second edge surrounding layer is the same as the material of the second edge supporting layer.

[0434] In this embodiment, the material of the second edge surrounding layer comprises metal, and the material of the second edge supporting layer comprises a non-metallic material. In another embodiment, the material of the second edge surrounding layer comprises metal, and the medium of the second edge supporting layer comprises air, i.e., an air layer. In another embodiment, the material of the second edge surrounding layer comprises metal, and the medium of the second edge supporting layer comprises vacuum, i.e., a vacuum layer. In another embodiment, the material of the second edge surrounding layer comprises metal, and the material of the second edge supporting layer comprises metal.

[0435] In this embodiment, the thickness of the second composite structure 890 is greater than the thickness of the second edge structure 851. In another embodiment, the thickness of the composite structure on the piezoelectric layer is equal to the thickness of the edge structure on the piezoelectric layer. In another embodiment, the thickness of the composite structure on the piezoelectric layer is less than the thickness of the edge structure on the piezoelectric layer.

[0436] In this embodiment, the material of the second edge extension layer 891 includes metal. In this embodiment, the material of the second edge extension layer 891 includes, but is not limited to, at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0437] In this embodiment, the medium of the second composite support layer 893 includes a non-metallic material. In this embodiment, the medium of the second composite support layer 893 includes, but is not limited to, at least one of the following: silicon dioxide, silicon oxycarbide, silicon oxyfluoride, and a polymer. The polymer includes, but is not limited to, at least one of the following: benzocyclobutene (i.e., BCB), a photosensitive epoxy resin photoresist (e.g., SU-8), and polyimide. In another embodiment, the medium of the composite support layer in the composite structure on the piezoelectric layer can be a vacuum, i.e., a vacuum layer. In another embodiment, the medium of the composite support layer in the composite structure on the piezoelectric layer can be air, i.e., an air layer.

[0438] In this embodiment, the second composite structure 890 and the first electrode layer 840 have no overlapping portion.

[0439] In this embodiment, the second composite structure 890 has no overlapping portion with the first composite structure 860. In this embodiment, the second composite structure 890 and the first composite structure 860 are located on both sides of the second electrode layer 880.

[0440] Figure 30 FIG. 8 is a schematic top view of a bulk acoustic wave resonator device 800 according to an embodiment of the present invention.

[0441] like Figure 30 As shown, in this embodiment, the first edge structure 850 and the second edge structure 851 have an overlapping portion 853. In this embodiment, the surrounding edge formed by the first edge structure 850 and the second edge structure 851 is annular. In this embodiment, the surrounding edge formed by the first edge structure 850 and the second edge structure 851 is octagonal. It should be noted that surrounding edges of other shapes known to those skilled in the art, such as hexagons, pentagons, etc., can also be applied to embodiments of the present invention. In this embodiment, the first composite structure 860 is adjacent to both sides of the first edge structure 850, and the second composite structure 890 is adjacent to both sides of the second edge structure 851.

[0442] like Figure 35As shown, an embodiment of the present invention provides a bulk acoustic wave resonator 900 comprising: a substrate 910; an intermediate layer 920, located on the substrate 910, wherein the upper surface side of the intermediate layer 920 comprises a cavity 930 and a groove 931, wherein the groove 931 is located on one side of the cavity 930 and communicates with the cavity 930, and the depth of the groove 931 is less than the depth of the cavity 930; a first electrode layer 940, wherein a first end 941 of the first electrode layer 940 is located in the cavity 930, and a second end 943 of the first electrode layer 940 is located in the groove 931, wherein the depth of the groove 931 is equal to the thickness of the first electrode layer 940; a piezoelectric layer 950, located The cavity 930 is covered on the first electrode layer 940 and the intermediate layer 920, wherein the piezoelectric layer 950 includes a first side 951 and a second side 953 opposite to the first side 951, the first electrode layer 940 and the intermediate layer 920 are located on the first side 951; the second electrode layer 960 is located on the second side 953 and is located on the piezoelectric layer 950; the edge structure 970 is located on the second side 953 and is located on the piezoelectric layer 950, the second electrode layer 960 is located on the inner side of the edge structure 970 (i.e., the side pointing to the central axis of the bulk acoustic wave resonator 900), and the edge structure 970 has an overlapping portion with the first electrode layer 940. and a composite structure 980, located on the second side 953, located on the piezoelectric layer 950, located outside the edge structure 970 (i.e., pointing to the side opposite to the central axis of the BAW resonator 900) and connected to the edge structure 970; wherein the composite structure 980 includes an edge extension layer 981, located on the second side 953, located above the piezoelectric layer 950, electrically connected to the edge structure 970, and a composite support layer 983, located on the second side 953, located on the piezoelectric layer 950, located between the piezoelectric layer 950 and the edge extension layer 981, connecting the edge structure 970, and the composite support layer 983 and the edge extension layer 981. 81 overlap, the edge extension layer 981 and the composite support layer 983 have a first overlapping portion with the first electrode layer 940; the composite structure 980 also includes an edge extension layer 985, which is located on the second side 953, above the piezoelectric layer 950, and electrically connected to the edge structure 970, and a composite support layer 987, which is located on the second side 953, on the piezoelectric layer 950, between the piezoelectric layer 950 and the edge extension layer 985, and connects the edge structure 970, the composite support layer 987 overlaps with the edge extension layer 985, and the edge extension layer 985 and the composite support layer 987 have a second overlapping portion with the first electrode layer 940.

[0443] It should be noted that the composite support layer 983 thickens the medium between the first electrode layer 940 and the edge extension layer 981, reducing the edge capacitance between the first electrode layer 940 and the edge extension layer 981, and the composite support layer 987 thickens the medium between the first electrode layer 940 and the edge extension layer 985, reducing the edge capacitance between the first electrode layer 940 and the edge extension layer 985, thereby improving the electromechanical coupling coefficient of the resonant device.

[0444] In addition, the edge structure 970 and the composite structure 980 form a reflective structure, which is located outside the second electrode layer 960, thereby reflecting the sound waves in the resonance region, blocking leakage waves, and improving the Q value.

[0445] In this embodiment, the material of the substrate 910 includes but is not limited to at least one of the following: silicon, silicon carbide, glass, gallium arsenide, gallium nitride, and ceramic.

[0446] In this embodiment, the material of the intermediate layer 920 includes, but is not limited to, at least one of the following: a polymer, an insulating dielectric, and polysilicon. In this embodiment, the polymer includes, but is not limited to, at least one of the following: benzocyclobutene (i.e., BCB), a photosensitive epoxy resin photoresist (e.g., SU-8), and polyimide. In this embodiment, the insulating dielectric includes, but is not limited to, at least one of the following: aluminum nitride, silicon dioxide, silicon nitride, and titanium oxide.

[0447] In this embodiment, the material of the first electrode layer 940 includes but is not limited to at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0448] In this embodiment, the piezoelectric layer 950 is a flat layer and also covers the upper surface of the intermediate layer 920. In this embodiment, the material of the piezoelectric layer 950 includes, but is not limited to, at least one of the following: aluminum nitride, aluminum nitride alloy, gallium nitride, zinc oxide, lithium tantalate, lithium niobate, lead zirconate titanate, or lead magnesium niobate-lead titanate.

[0449] In this embodiment, the piezoelectric layer 950 includes a plurality of crystal grains, including a first crystal grain and a second crystal grain, wherein the first crystal grain and the second crystal grain are any two crystal grains of the plurality of crystal grains. Those skilled in the art will appreciate that crystal orientations, crystal planes, and the like of crystal grains can be represented based on a coordinate system.

[0450] In this embodiment, the first grain can be represented based on a first three-dimensional coordinate system, and the second grain can be represented based on a second three-dimensional coordinate system, wherein the first three-dimensional coordinate system includes at least a first coordinate axis along the first direction and a third coordinate axis along the third direction, and the second three-dimensional coordinate system includes at least a second coordinate axis along the second direction and a fourth coordinate axis along the fourth direction, wherein the first coordinate axis corresponds to the height of the first grain, and the second coordinate axis corresponds to the height of the second grain.

[0451] In this embodiment, the first direction and the second direction are the same or opposite. It should be noted that the first direction and the second direction are the same means that the angle between the vector along the first direction and the vector along the second direction is within a range of 0 degrees to 5 degrees; the first direction and the second direction are opposite means that the angle between the vector along the first direction and the vector along the second direction is within a range of 175 degrees to 180 degrees.

[0452] In another embodiment, the first three-dimensional coordinate system is an ac three-dimensional coordinate system, wherein the first coordinate axis is the first c-axis and the third coordinate axis is the first a-axis; the second three-dimensional coordinate system is an ac three-dimensional coordinate system, wherein the second coordinate axis is the second c-axis and the fourth coordinate axis is the second a-axis, wherein the first c-axis and the second c-axis point in the same or opposite directions.

[0453] In another embodiment, the first three-dimensional coordinate system further includes a fifth coordinate axis along a fifth direction, and the second three-dimensional coordinate system further includes a sixth coordinate axis along a sixth direction. In another embodiment, the first direction and the second direction are the same or opposite, and the third direction and the fourth direction are the same or opposite. It should be noted that the third direction and the fourth direction are the same means that the angle between the vector along the third direction and the vector along the fourth direction ranges from 0 degrees to 5 degrees; the third direction and the fourth direction are opposite means that the angle between the vector along the third direction and the vector along the fourth direction ranges from 175 degrees to 180 degrees.

[0454] In another embodiment, the first 3D coordinate system is an xyz 3D coordinate system, wherein the first coordinate axis is the first z-axis, the third coordinate axis is the first y-axis, and the fifth coordinate axis is the first x-axis; and the second 3D coordinate system is an xyz 3D coordinate system, wherein the second coordinate axis is the second z-axis, the fourth coordinate axis is the second y-axis, and the sixth coordinate axis is the second x-axis. In another embodiment, the first z-axis and the second z-axis point in the same direction, and the first y-axis and the second y-axis point in the same direction. In another embodiment, the first z-axis and the second z-axis point in opposite directions, and the first y-axis and the second y-axis point in opposite directions. In another embodiment, the first z-axis and the second z-axis point in the same direction, and the first y-axis and the second y-axis point in opposite directions. In another embodiment, the first z-axis and the second z-axis point in the same direction, and the first y-axis and the second y-axis point in opposite directions. In another embodiment, the first z-axis and the second z-axis point in opposite directions, and the first y-axis and the second y-axis point in the same direction.

[0455] In this embodiment, the piezoelectric layer 950 includes a plurality of crystal grains, and the half-maximum width of the rocking curve of the crystal formed by the plurality of crystal grains is less than 2.5 degrees.

[0456] It should be noted that forming the piezoelectric layer 950 on a plane can prevent the piezoelectric layer 950 from including grains with obvious turns, thereby improving the electromechanical coupling coefficient of the resonant device and the Q value of the resonant device.

[0457] In this embodiment, the material of the second electrode layer 960 includes but is not limited to at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0458] In this embodiment, the portion of the first electrode layer 940 that overlaps with the second electrode layer 960 is located in the cavity 930 ; the portion of the electrode 960 that overlaps with the electrode 940 is located above the cavity 930 , corresponding to the cavity 930 .

[0459] In this embodiment, the edge structure 970 includes an edge surrounding layer, which is located on the second side 953 and above the piezoelectric layer 950, and the edge surrounding layer is electrically connected to the second electrode layer 960; and an edge supporting layer, which is located on the second side 953, on the piezoelectric layer 950, and between the piezoelectric layer 950 and the edge surrounding layer, and the edge supporting layer is connected to the second electrode layer 960, and the edge surrounding layer and the edge supporting layer overlap.

[0460] In this embodiment, the material of the edge surrounding layer is different from the material of the edge supporting layer. In another embodiment, the material of the edge surrounding layer is the same as the material of the edge supporting layer.

[0461] In this embodiment, the material of the edge surrounding layer comprises metal, and the material of the edge support layer comprises a non-metallic material. In another embodiment, the material of the edge surrounding layer comprises metal, and the medium of the edge support layer comprises air, i.e., an air layer. In another embodiment, the material of the edge surrounding layer comprises metal, and the medium of the edge support layer comprises vacuum, i.e., a vacuum layer. In another embodiment, the material of the edge surrounding layer comprises metal, and the material of the edge support layer comprises metal.

[0462] In this embodiment, the thickness of the composite structure 980 is greater than the thickness of the edge structure 970. In another embodiment, the thickness of the composite structure on the piezoelectric layer is equal to the thickness of the edge structure on the piezoelectric layer. In another embodiment, the thickness of the composite structure on the piezoelectric layer is less than the thickness of the edge structure on the piezoelectric layer.

[0463] In this embodiment, the material of the edge extension layer 981 includes metal. In this embodiment, the material of the edge extension layer 981 includes, but is not limited to, at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0464] In this embodiment, the medium of the composite support layer 983 includes a non-metallic material. In this embodiment, the medium of the composite support layer 983 includes, but is not limited to, at least one of the following: silicon dioxide, silicon oxycarbide, silicon oxyfluoride, and a polymer. The polymer includes, but is not limited to, at least one of the following: benzocyclobutene (i.e., BCB), a photosensitive epoxy resin photoresist (e.g., SU-8), and polyimide. In another embodiment, the medium of the composite support layer in the composite structure on the piezoelectric layer can be a vacuum, i.e., a vacuum layer. In another embodiment, the medium of the composite support layer in the composite structure on the piezoelectric layer can be air, i.e., an air layer.

[0465] In this embodiment, the material of the edge extension layer 985 includes metal. In this embodiment, the material of the edge extension layer 985 includes, but is not limited to, at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0466] In this embodiment, the medium of the composite support layer 987 includes a non-metallic material. In this embodiment, the medium of the composite support layer 987 includes, but is not limited to, at least one of the following: silicon dioxide, silicon oxycarbide, silicon oxyfluoride, and a polymer. The polymer includes, but is not limited to, at least one of the following: benzocyclobutene (i.e., BCB), a photosensitive epoxy resin photoresist (e.g., SU-8), and polyimide. In another embodiment, the medium of the composite support layer in the composite structure on the piezoelectric layer can be a vacuum, i.e., a vacuum layer. In another embodiment, the medium of the composite support layer in the composite structure on the piezoelectric layer can be air, i.e., an air layer.

[0467] In this embodiment, the edge extension layer 981 and the edge extension layer 985 have no overlapping portion. In this embodiment, the edge extension layer 981 and the edge extension layer 985 are located on both sides of the second electrode layer 960.

[0468] In this embodiment, the width of the first overlapping portion is equal to the width of the edge structure 970 , and the width of the second overlapping portion is equal to the width of the edge structure 970 .

[0469] Figure 34 FIG. 1 is a schematic top view of a bulk acoustic wave resonator device 900 according to an embodiment of the present invention.

[0470] like Figure 34 As shown, in this embodiment, the edge structure 970 is annular. In this embodiment, the edge structure 970 is octagonal. It should be noted that edge structures of other shapes known to those skilled in the art, such as hexagons, pentagons, etc., can also be applied to embodiments of the present invention. In this embodiment, the composite structure 980 is adjacent to two sides of the edge structure 970, wherein the edge extension layer 981 is adjacent to the first side, and the edge extension layer 985 is adjacent to the second side, and the first side and the second side are respectively located at both ends of the second electrode layer 960.

[0471] like Figure 39As shown, an embodiment of the present invention provides a bulk acoustic wave resonator device 1000 comprising: a substrate 1010; an intermediate layer 1020, located on the substrate 1010, wherein the upper surface side of the intermediate layer 1020 comprises a cavity 1030 and a groove 1031, wherein the groove 1031 is located on one side of the cavity 1030 and communicates with the cavity 1030, and the depth of the groove 1031 is less than the depth of the cavity 1030; a first electrode layer 1040, located in the cavity 1030; an edge structure 1050, located in the cavity 1030, wherein the first electrode layer 1040 is located on the inner side of the edge structure 1050 (i.e., pointing to the central axis of the bulk acoustic wave resonator 1000). The composite structure 1060 is located outside the edge structure 1050 (i.e., pointing to the side opposite to the central axis of the bulk acoustic wave resonator 1000), the first end of the composite structure 1060 is located in the cavity 1030, and the second end of the composite structure 1060 opposite to the first end is located in the groove 1031, wherein the depth of the groove 1031 is equal to the thickness of the composite structure 1060; wherein the composite structure 1060 includes an edge extension layer 1061, electrically connected to the edge structure 1050, and a composite support layer 1063, located on the edge extension layer 1061, connected to the edge structure 1050, the composite support layer 1063 overlaps with the edge extension layer 1061; wherein the composite structure 1060 further includes an edge extension layer 1065, which is located in the cavity 1030 and electrically connected to the edge structure 1050, and a composite support layer 1067, which is located on the edge extension layer 1061, located in the cavity 1030, connected to the edge structure 1050, and the composite support layer 1067 overlaps with the edge extension layer 1065; a piezoelectric layer 1070, which is located on the first electrode layer 1040, the edge structure 1050, the composite support layer 1063, the composite support layer 1067 and the intermediate layer 1020, covering the cavity 1030, wherein the piezoelectric layer 107 0 includes a first side 1071 and a second side 1073 opposite to the first side 1071, the first electrode layer 1040, the edge structure 1050, the composite structure 1060 and the intermediate layer 1020 are located on the first side 1071; the second electrode layer 1080 is located on the second side 1073 and is located on the piezoelectric layer 1070, the edge structure 1050 and the second electrode layer 1080 have an overlapping portion, the edge extension layer 1061 and the composite support layer 1063 have a first overlapping portion with the second electrode layer 1080, and the edge extension layer 1065 and the composite support layer 1067 have a second overlapping portion with the second electrode layer 1080.

[0472] It should be noted that the composite support layer 1063 thickens the medium between the second electrode layer 1080 and the edge extension layer 1061, reducing the edge capacitance between the second electrode layer 1080 and the edge extension layer 1061, and the composite support layer 1067 thickens the medium between the second electrode layer 1080 and the edge extension layer 1065, reducing the edge capacitance between the second electrode layer 1080 and the edge extension layer 1065, thereby improving the electromechanical coupling coefficient of the resonant device.

[0473] In addition, the edge structure 1050 and the composite structure 1060 form a reflective structure, which is located outside the first electrode layer 1040, thereby reflecting the sound waves in the resonance region, blocking leakage waves, and improving the Q value.

[0474] In this embodiment, the material of the substrate 1010 includes but is not limited to at least one of the following: silicon, silicon carbide, glass, gallium arsenide, gallium nitride, and ceramic.

[0475] In this embodiment, the material of the intermediate layer 1020 includes, but is not limited to, at least one of the following: a polymer, an insulating dielectric, and polysilicon. In this embodiment, the polymer includes, but is not limited to, at least one of the following: benzocyclobutene (i.e., BCB), a photosensitive epoxy resin photoresist (e.g., SU-8), and polyimide. In this embodiment, the insulating dielectric includes, but is not limited to, at least one of the following: aluminum nitride, silicon dioxide, silicon nitride, and titanium oxide.

[0476] In this embodiment, the material of the first electrode layer 1040 includes but is not limited to at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0477] In this embodiment, the edge structure 1050 includes an edge surrounding layer, which is located in the cavity 1030 and is electrically connected to the first electrode layer 1040; and an edge supporting layer, which is located in the cavity 1030 and on the edge surrounding layer, and is connected to the first electrode layer 1040, and the edge surrounding layer and the edge supporting layer overlap.

[0478] In this embodiment, the material of the edge surrounding layer is different from the material of the edge supporting layer. In another embodiment, the material of the edge surrounding layer is the same as the material of the edge supporting layer.

[0479] In this embodiment, the material of the edge surrounding layer comprises metal, and the material of the edge support layer comprises a non-metallic material. In another embodiment, the material of the edge surrounding layer comprises metal, and the medium of the edge support layer comprises air, i.e., an air layer. In another embodiment, the material of the edge surrounding layer comprises metal, and the medium of the edge support layer comprises vacuum, i.e., a vacuum layer. In another embodiment, the material of the edge surrounding layer comprises metal, and the material of the edge support layer comprises metal.

[0480] In this embodiment, the thickness of the composite structure 1060 is greater than the thickness of the edge structure 1050. In another embodiment, the thickness of the composite structure below the piezoelectric layer is equal to the thickness of the edge structure below the piezoelectric layer. In another embodiment, the thickness of the composite structure below the piezoelectric layer is less than the thickness of the edge structure below the piezoelectric layer.

[0481] In this embodiment, the material of the edge extension layer 1061 includes metal. In this embodiment, the material of the edge extension layer 1061 includes, but is not limited to, at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0482] In this embodiment, the medium of the composite support layer 1063 includes a non-metallic material. In this embodiment, the medium of the composite support layer 1063 includes, but is not limited to, at least one of the following: silicon dioxide, silicon oxycarbide, silicon oxyfluoride, and a polymer. The polymer includes, but is not limited to, at least one of the following: benzocyclobutene (i.e., BCB), a photosensitive epoxy resin photoresist (e.g., SU-8), and polyimide. In another embodiment, the medium of the first composite support layer in the composite structure below the piezoelectric layer can be a vacuum, i.e., a vacuum layer. In another embodiment, the medium of the first composite support layer in the composite structure below the piezoelectric layer can be air, i.e., an air layer.

[0483] In this embodiment, the material of the edge extension layer 1065 includes metal. In this embodiment, the material of the edge extension layer 1065 includes, but is not limited to, at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0484] In this embodiment, the medium of the composite support layer 1067 includes a non-metallic material. In this embodiment, the medium of the composite support layer 1067 includes, but is not limited to, at least one of the following: silicon dioxide, silicon oxycarbide, silicon oxyfluoride, and a polymer. The polymer includes, but is not limited to, at least one of the following: benzocyclobutene (i.e., BCB), a photosensitive epoxy resin photoresist (e.g., SU-8), and polyimide. In another embodiment, the medium of the second composite support layer in the composite structure below the piezoelectric layer can be a vacuum, i.e., a vacuum layer. In another embodiment, the medium of the second composite support layer in the composite structure below the piezoelectric layer can be air, i.e., an air layer.

[0485] In this embodiment, the edge extension layer 1061 and the edge extension layer 1065 have no overlapping portion. In this embodiment, the edge extension layer 1061 and the edge extension layer 1065 are located on both sides of the first electrode layer 1040.

[0486] In this embodiment, the piezoelectric layer 1070 is a flat layer and also covers the upper surface of the intermediate layer 1020. In this embodiment, the material of the piezoelectric layer 1070 includes, but is not limited to, at least one of the following: aluminum nitride, aluminum nitride alloy, gallium nitride, zinc oxide, lithium tantalate, lithium niobate, lead zirconate titanate, or lead magnesium niobate-lead titanate.

[0487] In this embodiment, the piezoelectric layer 1070 includes a plurality of crystal grains, the plurality of crystal grains including a first crystal grain and a second crystal grain, wherein the first crystal grain and the second crystal grain are any two crystal grains of the plurality of crystal grains. A person skilled in the art will appreciate that the crystal orientation, crystal plane, etc. of a crystal grain can be represented based on a coordinate system.

[0488] In this embodiment, the first grain can be represented based on a first three-dimensional coordinate system, and the second grain can be represented based on a second three-dimensional coordinate system, wherein the first three-dimensional coordinate system includes at least a first coordinate axis along the first direction and a third coordinate axis along the third direction, and the second three-dimensional coordinate system includes at least a second coordinate axis along the second direction and a fourth coordinate axis along the fourth direction, wherein the first coordinate axis corresponds to the height of the first grain, and the second coordinate axis corresponds to the height of the second grain.

[0489] In this embodiment, the first direction and the second direction are the same or opposite. It should be noted that the first direction and the second direction are the same means that the angle between the vector along the first direction and the vector along the second direction is within a range of 0 degrees to 5 degrees; the first direction and the second direction are opposite means that the angle between the vector along the first direction and the vector along the second direction is within a range of 175 degrees to 180 degrees.

[0490] In another embodiment, the first three-dimensional coordinate system is an ac three-dimensional coordinate system, wherein the first coordinate axis is the first c-axis and the third coordinate axis is the first a-axis; the second three-dimensional coordinate system is an ac three-dimensional coordinate system, wherein the second coordinate axis is the second c-axis and the fourth coordinate axis is the second a-axis, wherein the first c-axis and the second c-axis point in the same or opposite directions.

[0491] In another embodiment, the first three-dimensional coordinate system further includes a fifth coordinate axis along a fifth direction, and the second three-dimensional coordinate system further includes a sixth coordinate axis along a sixth direction. In another embodiment, the first direction and the second direction are the same or opposite, and the third direction and the fourth direction are the same or opposite. It should be noted that the third direction and the fourth direction are the same means that the angle between the vector along the third direction and the vector along the fourth direction ranges from 0 degrees to 5 degrees; the third direction and the fourth direction are opposite means that the angle between the vector along the third direction and the vector along the fourth direction ranges from 175 degrees to 180 degrees.

[0492] In another embodiment, the first 3D coordinate system is an xyz 3D coordinate system, wherein the first coordinate axis is the first z-axis, the third coordinate axis is the first y-axis, and the fifth coordinate axis is the first x-axis; and the second 3D coordinate system is an xyz 3D coordinate system, wherein the second coordinate axis is the second z-axis, the fourth coordinate axis is the second y-axis, and the sixth coordinate axis is the second x-axis. In another embodiment, the first z-axis and the second z-axis point in the same direction, and the first y-axis and the second y-axis point in the same direction. In another embodiment, the first z-axis and the second z-axis point in opposite directions, and the first y-axis and the second y-axis point in opposite directions. In another embodiment, the first z-axis and the second z-axis point in the same direction, and the first y-axis and the second y-axis point in opposite directions. In another embodiment, the first z-axis and the second z-axis point in the same direction, and the first y-axis and the second y-axis point in opposite directions. In another embodiment, the first z-axis and the second z-axis point in opposite directions, and the first y-axis and the second y-axis point in the same direction.

[0493] In this embodiment, the piezoelectric layer 1070 includes a plurality of crystal grains, and the half-maximum width of the rocking curve of the crystal formed by the plurality of crystal grains is less than 2.5 degrees.

[0494] It should be noted that forming the piezoelectric layer 1070 on a plane can ensure that the piezoelectric layer 1070 does not include grains with obvious turns, thereby improving the electromechanical coupling coefficient of the resonant device and the Q value of the resonant device.

[0495] In this embodiment, the material of the second electrode layer 1080 includes but is not limited to at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0496] In this embodiment, the portion of the first electrode layer 1040 that overlaps with the second electrode layer 1080 is located in the cavity 1030 ; the portion of the electrode 1080 that overlaps with the electrode 1040 is located above the cavity 1030 , corresponding to the cavity 1030 .

[0497] In this embodiment, the width of the first overlapping portion is equal to the width of the edge structure 1050 , and the width of the second overlapping portion is equal to the width of the edge structure 1050 .

[0498] Figure 38 FIG. 1 is a schematic top view of a bulk acoustic wave resonator device 1000 according to an embodiment of the present invention.

[0499] like Figure 38 As shown, in this embodiment, the edge structure 1050 is ring-shaped. In this embodiment, the edge structure 1050 is octagonal. It should be noted that edge structures of other shapes known to those skilled in the art, such as hexagons, pentagons, etc., can also be applied to embodiments of the present invention. In this embodiment, the composite structure 1060 is adjacent to the four sides of the edge structure 1050, wherein the edge extension layer 1061 is adjacent to the first side and the second side, and the edge extension layer 1065 is adjacent to the third side and the fourth side, the first side and the second side are located at the first end of the first electrode layer 1040, and the third side and the fourth side are located at the second end of the first electrode layer 1040.

[0500] like Figure 43As shown, an embodiment of the present invention provides a bulk acoustic wave resonator 1100 comprising: a substrate 1110; an intermediate layer 1120, located on the substrate 1110, wherein the upper surface side of the intermediate layer 1120 comprises a cavity 1130 and a groove 1131, wherein the groove 1131 is located on one side of the cavity 1130 and communicates with the cavity 1130, and the depth of the groove 1131 is less than the depth of the cavity 1130; a first electrode layer 1140, located in the cavity 1130; a first edge structure 1150, located in the cavity 1130, the first electrode layer 1140 is located on the inner side of the first edge structure 1150 (i.e., pointing to the The first composite structure 1160 is located outside the first edge structure 1150 (i.e., pointing to the side opposite to the central axis of the BAW resonator 1100); the first end of the first composite structure 1160 is connected to the first edge structure 1150, and the second end of the first composite structure 1160 opposite to the first end is located in the groove 1131, wherein the depth of the groove 1131 is equal to the thickness of the first composite structure 1160, and the first composite structure 1160 includes a first edge extension layer 1161, which is electrically connected to the first edge structure 1150 and the first composite structure 1160. The support layer 1163 is located on the first edge extension layer 1161 and is connected to the first edge structure 1150. The first composite support layer 1163 overlaps with the first edge extension layer 1161. The piezoelectric layer 1170 is located on the first electrode layer 1140, the first edge structure 1150, the first composite support layer 1163 and the intermediate layer 1120, covering the cavity 1130. The piezoelectric layer 1170 includes a first side 1171 and a second side 1173 opposite to the first side 1171. The first electrode layer 1140, the first edge structure 1150, the first composite structure 1160 and the intermediate layer 1120 are connected to the first edge extension layer 1150. The interlayer 1120 is located on the first side 1171; the second electrode layer 1180 is located on the second side 1173 and is located on the piezoelectric layer 1170; the first edge structure 1150 and the second electrode layer 1180 have an overlapping portion; the first edge extension layer 1161 and the first composite support layer 1163 have a first overlapping portion with the second electrode layer 1180; the second edge structure 1151 is located on the second side 1173 and is located on the piezoelectric layer 1170; the second electrode layer 1180 is located inside the second edge structure 1151; and the second edge structure 1151 has an overlapping portion with the first electrode layer 1140;and a second composite structure 1190 located on the second side 1173, on the piezoelectric layer 1170, outside the second edge structure 1151, and connected to the second edge structure 1151. Second composite structure 1190 includes a second edge extension layer 1191 located on the second side 1173, above the piezoelectric layer 1170, and electrically connected to the second edge structure 1151; and a second composite support layer 1193 located on the second side 1173, on the piezoelectric layer 1170, between the piezoelectric layer 1170 and the second edge extension layer 1191, and connected to the second edge structure 1151. Second composite support layer 1193 overlaps with second edge extension layer 1191, and both second edge extension layer 1191 and second composite support layer 1193 have a second overlapping portion with first electrode layer 1140.

[0501] It should be noted that the first composite support layer 1163 thickens the medium between the second electrode layer 1180 and the first edge extension layer 1161, reducing the edge capacitance between the second electrode layer 1180 and the first edge extension layer 1161, and the second composite support layer 1193 thickens the medium between the first electrode layer 1140 and the second edge extension layer 1191, reducing the edge capacitance between the first electrode layer 1140 and the second edge extension layer 1191, thereby improving the electromechanical coupling coefficient of the resonant device.

[0502] In addition, the first edge structure 1150 and the first composite structure 1160 form a first reflective structure, which is located on the outside of the first electrode layer 1140; the second edge structure 1151 and the second composite structure 1190 form a second reflective structure, which is located on the outside of the second electrode layer 1180, thereby reflecting the sound waves in the resonance area, blocking leakage waves, and improving the Q value.

[0503] In this embodiment, the material of the substrate 1110 includes but is not limited to at least one of the following: silicon, silicon carbide, glass, gallium arsenide, gallium nitride, and ceramics.

[0504] In this embodiment, the material of the intermediate layer 1120 includes, but is not limited to, at least one of the following: a polymer, an insulating dielectric, and polysilicon. In this embodiment, the polymer includes, but is not limited to, at least one of the following: benzocyclobutene (i.e., BCB), a photosensitive epoxy resin photoresist (e.g., SU-8), and polyimide. In this embodiment, the insulating dielectric includes, but is not limited to, at least one of the following: aluminum nitride, silicon dioxide, silicon nitride, and titanium oxide.

[0505] In this embodiment, the material of the first electrode layer 1140 includes but is not limited to at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0506] In this embodiment, the first edge structure 1150 includes a first edge surrounding layer, which is located in the cavity 1130 and is electrically connected to the first electrode layer 1140; and a first edge supporting layer, which is located in the cavity 1130 and on the first edge surrounding layer, and is connected to the first electrode layer 1140, and the first edge surrounding layer and the first edge supporting layer overlap.

[0507] In this embodiment, the material of the first edge surrounding layer is different from the material of the first edge supporting layer. In another embodiment, the material of the first edge surrounding layer is the same as the material of the first edge supporting layer.

[0508] In this embodiment, the material of the first edge surrounding layer comprises metal, and the material of the first edge supporting layer comprises a non-metallic material. In another embodiment, the material of the first edge surrounding layer comprises metal, and the medium of the first edge supporting layer comprises air, i.e., an air layer. In another embodiment, the material of the first edge surrounding layer comprises metal, and the medium of the first edge supporting layer comprises vacuum, i.e., a vacuum layer. In another embodiment, the material of the first edge surrounding layer comprises metal, and the material of the first edge supporting layer comprises metal.

[0509] In this embodiment, the thickness of the first composite structure 1160 is greater than the thickness of the first edge structure 1150. In another embodiment, the thickness of the composite structure below the piezoelectric layer is equal to the thickness of the edge structure below the piezoelectric layer. In another embodiment, the thickness of the composite structure below the piezoelectric layer is less than the thickness of the edge structure below the piezoelectric layer.

[0510] In this embodiment, the material of the first edge extension layer 1161 includes metal. In this embodiment, the material of the edge extension layer 1061 includes but is not limited to at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0511] In this embodiment, the medium of the first composite support layer 1163 includes a non-metallic material. In this embodiment, the medium of the first composite support layer 1163 includes, but is not limited to, at least one of the following: silicon dioxide, silicon oxycarbide, silicon oxyfluoride, and a polymer. The polymer includes, but is not limited to, at least one of the following: benzocyclobutene (i.e., BCB), a photosensitive epoxy resin photoresist (e.g., SU-8), and polyimide. In another embodiment, the medium of the composite support layer in the composite structure below the piezoelectric layer can be a vacuum, i.e., a vacuum layer. In another embodiment, the medium of the composite support layer in the composite structure below the piezoelectric layer can be air, i.e., an air layer.

[0512] In this embodiment, the piezoelectric layer 1170 is a flat layer and also covers the upper surface of the intermediate layer 1120. In this embodiment, the material of the piezoelectric layer 1170 includes, but is not limited to, at least one of the following: aluminum nitride, aluminum nitride alloy, gallium nitride, zinc oxide, lithium tantalate, lithium niobate, lead zirconate titanate, or lead magnesium niobate-lead titanate.

[0513] In this embodiment, the piezoelectric layer 1170 includes a plurality of crystal grains, including a first crystal grain and a second crystal grain, wherein the first crystal grain and the second crystal grain are any two crystal grains of the plurality of crystal grains. Those skilled in the art will appreciate that crystal orientations, crystal planes, and the like of crystal grains can be represented based on a coordinate system.

[0514] In this embodiment, the first grain can be represented based on a first three-dimensional coordinate system, and the second grain can be represented based on a second three-dimensional coordinate system, wherein the first three-dimensional coordinate system includes at least a first coordinate axis along the first direction and a third coordinate axis along the third direction, and the second three-dimensional coordinate system includes at least a second coordinate axis along the second direction and a fourth coordinate axis along the fourth direction, wherein the first coordinate axis corresponds to the height of the first grain, and the second coordinate axis corresponds to the height of the second grain.

[0515] In this embodiment, the first direction and the second direction are the same or opposite. It should be noted that the first direction and the second direction are the same means that the angle between the vector along the first direction and the vector along the second direction is within a range of 0 degrees to 5 degrees; the first direction and the second direction are opposite means that the angle between the vector along the first direction and the vector along the second direction is within a range of 175 degrees to 180 degrees.

[0516] In another embodiment, the first three-dimensional coordinate system is an ac three-dimensional coordinate system, wherein the first coordinate axis is the first c-axis and the third coordinate axis is the first a-axis; the second three-dimensional coordinate system is an ac three-dimensional coordinate system, wherein the second coordinate axis is the second c-axis and the fourth coordinate axis is the second a-axis, wherein the first c-axis and the second c-axis point in the same or opposite directions.

[0517] In another embodiment, the first three-dimensional coordinate system further includes a fifth coordinate axis along a fifth direction, and the second three-dimensional coordinate system further includes a sixth coordinate axis along a sixth direction. In another embodiment, the first direction and the second direction are the same or opposite, and the third direction and the fourth direction are the same or opposite. It should be noted that the third direction and the fourth direction are the same means that the angle between the vector along the third direction and the vector along the fourth direction ranges from 0 degrees to 5 degrees; the third direction and the fourth direction are opposite means that the angle between the vector along the third direction and the vector along the fourth direction ranges from 175 degrees to 180 degrees.

[0518] In another embodiment, the first 3D coordinate system is an xyz 3D coordinate system, wherein the first coordinate axis is the first z-axis, the third coordinate axis is the first y-axis, and the fifth coordinate axis is the first x-axis; and the second 3D coordinate system is an xyz 3D coordinate system, wherein the second coordinate axis is the second z-axis, the fourth coordinate axis is the second y-axis, and the sixth coordinate axis is the second x-axis. In another embodiment, the first z-axis and the second z-axis point in the same direction, and the first y-axis and the second y-axis point in the same direction. In another embodiment, the first z-axis and the second z-axis point in opposite directions, and the first y-axis and the second y-axis point in opposite directions. In another embodiment, the first z-axis and the second z-axis point in the same direction, and the first y-axis and the second y-axis point in opposite directions. In another embodiment, the first z-axis and the second z-axis point in the same direction, and the first y-axis and the second y-axis point in opposite directions. In another embodiment, the first z-axis and the second z-axis point in opposite directions, and the first y-axis and the second y-axis point in the same direction.

[0519] In this embodiment, the piezoelectric layer 1170 includes a plurality of crystal grains, and the half-peak width of the rocking curve of the crystal formed by the plurality of crystal grains is less than 2.5 degrees.

[0520] It should be noted that forming the piezoelectric layer 1170 on a plane can ensure that the piezoelectric layer 1170 does not include grains with obvious turns, thereby improving the electromechanical coupling coefficient of the resonant device and the Q value of the resonant device.

[0521] In this embodiment, the material of the second electrode layer 1180 includes but is not limited to at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0522] In this embodiment, the portion of the first electrode layer 1140 that overlaps with the second electrode layer 1180 is located in the cavity 1130 ; the portion of the electrode 1180 that overlaps with the electrode 1140 is located above the cavity 1130 , corresponding to the cavity 1130 .

[0523] In this embodiment, the second edge structure 1151 includes a second edge surrounding layer, located on the second side 1173, above the piezoelectric layer 1170, and electrically connected to the second electrode layer 1180; and a second edge supporting layer, located on the second side 1173, on the piezoelectric layer 1170, between the piezoelectric layer 1170 and the second edge surrounding layer, the second edge supporting layer is connected to the second electrode layer 1180, and the second edge surrounding layer and the second edge supporting layer overlap.

[0524] In this embodiment, the material of the second edge surrounding layer is different from the material of the second edge supporting layer. In another embodiment, the material of the second edge surrounding layer is the same as the material of the second edge supporting layer.

[0525] In this embodiment, the material of the second edge surrounding layer comprises metal, and the material of the second edge supporting layer comprises a non-metallic material. In another embodiment, the material of the second edge surrounding layer comprises metal, and the medium of the second edge supporting layer comprises air, i.e., an air layer. In another embodiment, the material of the second edge surrounding layer comprises metal, and the medium of the second edge supporting layer comprises vacuum, i.e., a vacuum layer. In another embodiment, the material of the second edge surrounding layer comprises metal, and the material of the second edge supporting layer comprises metal.

[0526] In this embodiment, the thickness of the second composite structure 1190 is greater than the thickness of the second edge structure 1151. In another embodiment, the thickness of the composite structure on the piezoelectric layer is equal to the thickness of the edge structure on the piezoelectric layer. In another embodiment, the thickness of the composite structure on the piezoelectric layer is less than the thickness of the edge structure on the piezoelectric layer.

[0527] In this embodiment, the material of the second edge extension layer 1191 includes metal. In this embodiment, the material of the second edge extension layer 1191 includes, but is not limited to, at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0528] In this embodiment, the medium of the second composite support layer 1193 includes a non-metallic material. In this embodiment, the medium of the second composite support layer 1193 includes, but is not limited to, at least one of the following: silicon dioxide, silicon oxycarbide, silicon oxyfluoride, and a polymer. The polymer includes, but is not limited to, at least one of the following: benzocyclobutene (i.e., BCB), a photosensitive epoxy resin photoresist (e.g., SU-8), and polyimide. In another embodiment, the medium of the composite support layer in the composite structure on the piezoelectric layer can be a vacuum, i.e., a vacuum layer. In another embodiment, the medium of the composite support layer in the composite structure on the piezoelectric layer can be air, i.e., an air layer.

[0529] In this embodiment, the first composite structure 1160 and the second composite structure 1190 have no overlapping portion. In this embodiment, the first composite structure 1160 and the second composite structure 1190 are located on both sides of the first electrode layer 1140 .

[0530] In this embodiment, the width of the first overlapping portion is equal to the width of the first edge structure 1150 , and the width of the second overlapping portion is equal to the width of the second edge structure 1151 .

[0531] Figure 42 FIG1 is a schematic top view of a bulk acoustic wave resonator device 1100 according to an embodiment of the present invention.

[0532] like Figure 42As shown, in this embodiment, the first edge structure 1150 and the second edge structure 1151 partially overlap to form a peripheral structure. In this embodiment, the peripheral structure is octagonal. It should be noted that peripheral structures of other shapes known to those skilled in the art, such as hexagons, pentagons, etc., can also be applied to the embodiments of the present invention. In this embodiment, the first composite structure 1160 is adjacent to one side of the first edge structure 1150, and the second composite structure 1190 is adjacent to one side of the second edge structure 1151.

[0533] like Figure 47As shown, an embodiment of the present invention provides a bulk acoustic wave resonator device 1200 comprising: a substrate 1210; an intermediate layer 1220, located on the substrate 1210, wherein the upper surface side of the intermediate layer 1220 comprises a cavity 1230 and a groove 1231, wherein the groove 1231 is located on one side of the cavity 1230 and communicates with the cavity 1230, and the depth of the groove 1231 is less than the depth of the cavity 1230; a first electrode layer 1240, wherein the first end 1241 of the first electrode layer 1240 is located in the cavity 1230, and the second end 1243 of the first electrode layer 1240 is located in the cavity 1230. Located in the groove 1231, wherein the depth of the groove 1231 is equal to the thickness of the first electrode layer 1240; a piezoelectric layer 1250, located on the first electrode layer 1240 and the intermediate layer 1220, covering the cavity 1230, wherein the piezoelectric layer 1250 includes a first side 1251 and a second side 1253 opposite to the first side 1251, the first electrode layer 1240 and the intermediate layer 1220 are located on the first side 1251; a second electrode layer 1260, located on the second side 1253, located on the piezoelectric layer 1250; and a composite structure 127 0, the composite structure 1270 includes: an edge portion 1271, located on the second side 1253, located on the piezoelectric layer 1250, the second electrode layer 1260 is located on the inner side of the edge portion 1271 (that is, facing the side of the central axis of the BAW resonator 1200), and the edge portion 1271 and the first electrode layer 1240 have an overlapping portion; an extension portion (not marked), located on the second side 1253, located on the piezoelectric layer 1250, located on the outer side of the edge portion 1271 (that is, facing the side opposite to the central axis of the BAW resonator 1200) and connected to the an edge portion 1271; the extension portion includes an edge extension layer 1273, located on the second side 1253, located above the piezoelectric layer 1250, electrically connected to the edge portion 1271, and a composite support layer 1275, located on the second side 1253, located on the piezoelectric layer 1250, located between the piezoelectric layer 1250 and the edge extension layer 1273, and connected to the edge portion 1271; the composite support layer 1275 overlaps with the edge extension layer 1273, and the edge extension layer 1273 and the composite support layer 1275 have a first overlapping portion with the first electrode layer 1240;The extension portion further includes an edge extension layer 1277 located on the second side 1253, above the piezoelectric layer 1250, and electrically connected to the edge portion 1271; and a composite support layer 1279 located on the second side 1253, above the piezoelectric layer 1250, between the piezoelectric layer 1250 and the edge extension layer 1277, and connected to the edge portion 1271. The composite support layer 1279 overlaps with the edge extension layer 1277, and the edge extension layer 1277 and the composite support layer 1279 form a second overlapping portion with the first electrode layer 1240.

[0534] It should be noted that the composite support layer 1275 thickens the medium between the first electrode layer 1240 and the edge extension layer 1273, reducing the edge capacitance between the first electrode layer 1240 and the edge extension layer 1273, and the composite support layer 1279 thickens the medium between the first electrode layer 1240 and the edge extension layer 1277, reducing the edge capacitance between the first electrode layer 1240 and the edge extension layer 1277, thereby improving the electromechanical coupling coefficient of the resonant device.

[0535] In addition, the edge portion 1271 and the extension portion form a reflective structure, which is located outside the second electrode layer 1260, thereby reflecting the sound waves in the resonance region, blocking leakage waves, and improving the Q value.

[0536] In this embodiment, the material of the substrate 1210 includes but is not limited to at least one of the following: silicon, silicon carbide, glass, gallium arsenide, gallium nitride, and ceramic.

[0537] In this embodiment, the material of the intermediate layer 1220 includes, but is not limited to, at least one of the following: a polymer, an insulating dielectric, and polysilicon. In this embodiment, the polymer includes, but is not limited to, at least one of the following: benzocyclobutene (i.e., BCB), a photosensitive epoxy resin photoresist (e.g., SU-8), and polyimide. In this embodiment, the insulating dielectric includes, but is not limited to, at least one of the following: aluminum nitride, silicon dioxide, silicon nitride, and titanium oxide.

[0538] In this embodiment, the material of the first electrode layer 1240 includes but is not limited to at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0539] In this embodiment, the piezoelectric layer 1250 is a flat layer and also covers the upper surface of the intermediate layer 1220. In this embodiment, the material of the piezoelectric layer 1250 includes, but is not limited to, at least one of the following: aluminum nitride, aluminum nitride alloy, gallium nitride, zinc oxide, lithium tantalate, lithium niobate, lead zirconate titanate, or lead magnesium niobate-lead titanate.

[0540] In this embodiment, the piezoelectric layer 1250 includes a plurality of crystal grains, including a first crystal grain and a second crystal grain, wherein the first crystal grain and the second crystal grain are any two crystal grains of the plurality of crystal grains. A person skilled in the art will appreciate that the crystal orientation, crystal plane, etc. of a crystal grain can be represented based on a coordinate system.

[0541] In this embodiment, the first grain can be represented based on a first three-dimensional coordinate system, and the second grain can be represented based on a second three-dimensional coordinate system, wherein the first three-dimensional coordinate system includes at least a first coordinate axis along the first direction and a third coordinate axis along the third direction, and the second three-dimensional coordinate system includes at least a second coordinate axis along the second direction and a fourth coordinate axis along the fourth direction, wherein the first coordinate axis corresponds to the height of the first grain, and the second coordinate axis corresponds to the height of the second grain.

[0542] In this embodiment, the first direction and the second direction are the same or opposite. It should be noted that the first direction and the second direction are the same means that the angle between the vector along the first direction and the vector along the second direction is within a range of 0 degrees to 5 degrees; the first direction and the second direction are opposite means that the angle between the vector along the first direction and the vector along the second direction is within a range of 175 degrees to 180 degrees.

[0543] In another embodiment, the first three-dimensional coordinate system is an ac three-dimensional coordinate system, wherein the first coordinate axis is the first c-axis and the third coordinate axis is the first a-axis; the second three-dimensional coordinate system is an ac three-dimensional coordinate system, wherein the second coordinate axis is the second c-axis and the fourth coordinate axis is the second a-axis, wherein the first c-axis and the second c-axis point in the same or opposite directions.

[0544] In another embodiment, the first three-dimensional coordinate system further includes a fifth coordinate axis along a fifth direction, and the second three-dimensional coordinate system further includes a sixth coordinate axis along a sixth direction. In another embodiment, the first direction and the second direction are the same or opposite, and the third direction and the fourth direction are the same or opposite. It should be noted that the third direction and the fourth direction are the same means that the angle between the vector along the third direction and the vector along the fourth direction ranges from 0 degrees to 5 degrees; the third direction and the fourth direction are opposite means that the angle between the vector along the third direction and the vector along the fourth direction ranges from 175 degrees to 180 degrees.

[0545] In another embodiment, the first 3D coordinate system is an xyz 3D coordinate system, wherein the first coordinate axis is the first z-axis, the third coordinate axis is the first y-axis, and the fifth coordinate axis is the first x-axis; and the second 3D coordinate system is an xyz 3D coordinate system, wherein the second coordinate axis is the second z-axis, the fourth coordinate axis is the second y-axis, and the sixth coordinate axis is the second x-axis. In another embodiment, the first z-axis and the second z-axis point in the same direction, and the first y-axis and the second y-axis point in the same direction. In another embodiment, the first z-axis and the second z-axis point in opposite directions, and the first y-axis and the second y-axis point in opposite directions. In another embodiment, the first z-axis and the second z-axis point in the same direction, and the first y-axis and the second y-axis point in opposite directions. In another embodiment, the first z-axis and the second z-axis point in the same direction, and the first y-axis and the second y-axis point in opposite directions. In another embodiment, the first z-axis and the second z-axis point in opposite directions, and the first y-axis and the second y-axis point in the same direction.

[0546] In this embodiment, the piezoelectric layer 1250 includes a plurality of crystal grains, and the half-maximum width of the rocking curve of the crystal formed by the plurality of crystal grains is less than 2.5 degrees.

[0547] It should be noted that forming the piezoelectric layer 1250 on a plane can ensure that the piezoelectric layer 1250 does not include grains with obvious turns, thereby improving the electromechanical coupling coefficient of the resonant device and the Q value of the resonant device.

[0548] In this embodiment, the material of the second electrode layer 1260 includes but is not limited to at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0549] In this embodiment, the portion of the first electrode layer 1240 that overlaps with the second electrode layer 1260 is located in the cavity 1230 ; the portion of the electrode 1260 that overlaps with the electrode 1240 is located above the cavity 1230 , corresponding to the cavity 1230 .

[0550] In this embodiment, the edge portion 1271 includes an edge surrounding layer, which is located on the second side 1253 and above the piezoelectric layer 1250, and the edge surrounding layer is electrically connected to the second electrode layer 1260; and an edge supporting layer, which is located on the second side 1253, on the piezoelectric layer 1250, and between the piezoelectric layer 1250 and the edge surrounding layer, and the edge supporting layer is connected to the second electrode layer 1260, and the edge surrounding layer and the edge supporting layer overlap.

[0551] In this embodiment, the material of the edge surrounding layer is different from the material of the edge supporting layer. In another embodiment, the material of the edge surrounding layer is the same as the material of the edge supporting layer.

[0552] In this embodiment, the material of the edge surrounding layer comprises metal, and the material of the edge support layer comprises a non-metallic material. In another embodiment, the material of the edge surrounding layer comprises metal, and the medium of the edge support layer comprises air, i.e., an air layer. In another embodiment, the material of the edge surrounding layer comprises metal, and the medium of the edge support layer comprises vacuum, i.e., a vacuum layer. In another embodiment, the material of the edge surrounding layer comprises metal, and the material of the edge support layer comprises metal.

[0553] In this embodiment, the thickness of the extension portion is equal to the thickness of the edge portion 1271 .

[0554] In this embodiment, the material of the edge extension layer 1273 includes metal. In this embodiment, the material of the edge extension layer 1273 includes, but is not limited to, at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0555] In this embodiment, the medium of the composite support layer 1275 includes a non-metallic material. In this embodiment, the medium of the composite support layer 1275 includes, but is not limited to, at least one of the following: silicon dioxide, silicon oxycarbide, silicon oxyfluoride, and a polymer. The polymer includes, but is not limited to, at least one of the following: benzocyclobutene (i.e., BCB), a photosensitive epoxy resin photoresist (e.g., SU-8), and polyimide. In another embodiment, the medium of the first composite support layer of the extension portion on the piezoelectric layer can be a vacuum, i.e., a vacuum layer. In another embodiment, the medium of the first composite support layer of the extension portion on the piezoelectric layer can be air, i.e., an air layer.

[0556] In this embodiment, the thickness of the composite support layer 1275 is greater than the thickness of the edge support layer. In another embodiment, the thickness of the first composite support layer of the extension portion is equal to the thickness of the edge support layer of the edge portion. In another embodiment, the thickness of the first composite support layer of the extension portion is less than the thickness of the edge support layer of the edge portion.

[0557] In this embodiment, the material of the edge extension layer 1277 includes metal. In this embodiment, the material of the edge extension layer 1277 includes, but is not limited to, at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0558] In this embodiment, the medium of the composite support layer 1279 includes a non-metallic material. In this embodiment, the medium of the composite support layer 1279 includes, but is not limited to, at least one of the following: silicon dioxide, silicon oxycarbide, silicon oxyfluoride, and a polymer. The polymer includes, but is not limited to, at least one of the following: benzocyclobutene (i.e., BCB), a photosensitive epoxy resin photoresist (e.g., SU-8), and polyimide. In another embodiment, the medium of the second composite support layer of the extension portion on the piezoelectric layer can be a vacuum, i.e., a vacuum layer. In another embodiment, the medium of the second composite support layer of the extension portion on the piezoelectric layer can be air, i.e., an air layer.

[0559] In this embodiment, the thickness of the composite support layer 1279 is greater than the thickness of the edge support layer. In another embodiment, the thickness of the second composite support layer in the extension portion is equal to the thickness of the edge support layer in the edge portion. In another embodiment, the thickness of the second composite support layer in the extension portion is less than the thickness of the edge support layer in the edge portion.

[0560] In this embodiment, the edge extension layer 1273 and the edge extension layer 1277 have no overlapping portion. In this embodiment, the edge extension layer 1273 and the edge extension layer 1277 are located on both sides of the second electrode layer 1260.

[0561] In this embodiment, the width of the first overlapping portion is equal to the width of the edge portion 1271 , and the width of the second overlapping portion is equal to the width of the edge portion 1271 .

[0562] Figure 46 1 is a schematic top view of a bulk acoustic wave resonator device 1200 according to an embodiment of the present invention.

[0563] like Figure 46 As shown, in this embodiment, the edge portion 1271 is annular. In this embodiment, the edge portion 1271 is octagonal. It should be noted that edge portions of other shapes known to those skilled in the art, such as hexagons, pentagons, etc., can also be applied to the embodiments of the present invention. In this embodiment, the extension portion is adjacent to both sides of the edge portion 1271, wherein the edge extension layer 1273 is adjacent to the first side, and the edge extension layer 1277 is adjacent to the second side, and the first side and the second side are respectively located at the two ends of the second electrode layer 1260.

[0564] like Figure 51As shown, an embodiment of the present invention provides a bulk acoustic wave resonator 1300 comprising: a substrate 1310; an intermediate layer 1320, located on the substrate 1310, wherein the upper surface side of the intermediate layer 1320 comprises a cavity 1330 and a groove 1331, wherein the groove 1331 is located on one side of the cavity 1330 and communicates with the cavity 1330, and the depth of the groove 1331 is less than the depth of the cavity 1330; a first electrode layer 1340, located in the cavity 1330; a composite structure 1350, wherein the composite structure 1350 comprises: an edge portion 1351, located in the cavity 1330, the first electrode layer 1340 is located at the edge portion The edge portion 1351 is located inside (i.e., pointing to the side of the central axis of the BAW resonator 1300); an extension portion (not marked) is located outside the edge portion 1351 (i.e., pointing to the side opposite to the central axis of the BAW resonator 1300), a first end of the extension portion is located in the cavity 1330, and a second end of the extension portion opposite to the first end is located in the groove 1331, wherein the depth of the groove 1331 is equal to the thickness of the extension portion; wherein the extension portion includes an edge extension layer 1353, electrically connected to the edge portion 1351, and a composite support layer 1355, located on the edge extension layer 1353, connecting the edge portion 1351, the composite support layer 1355 overlaps with the edge extension layer 1353; the extension portion further includes an edge extension layer 1357, located in the cavity 1330, electrically connected to the edge portion 1351, and a composite support layer 1359, located on the edge extension layer 1357, located in the cavity 1330, connected to the edge portion 1351, the composite support layer 1359 overlaps with the edge extension layer 1357; a piezoelectric layer 1360, located on the first electrode layer 1340, the edge portion 1351, the composite support layer 1355, the composite support layer 1359 and the intermediate layer 1320, covering the cavity 1330 , wherein the piezoelectric layer 1360 includes a first side 1361 and a second side 1363 opposite to the first side 1361, the first electrode layer 1340, the composite structure 1350 and the intermediate layer 1320 are located on the first side 1361; the electrode layer 1370 is located on the second side 1363, and is located on the piezoelectric layer 1360, the edge portion 1351 and the electrode layer 1370 have an overlapping portion, the edge extension layer 1353 and the composite support layer 1355 and the electrode layer 1370 have a first overlapping portion, and the edge extension layer 1357 and the composite support layer 1359 and the electrode layer 1370 have a second overlapping portion.

[0565] It should be noted that the composite support layer 1355 thickens the medium between the electrode layer 1370 and the edge extension layer 1353, reducing the edge capacitance between the electrode layer 1370 and the edge extension layer 1353, and the composite support layer 1359 thickens the medium between the electrode layer 1370 and the edge extension layer 1357, reducing the edge capacitance between the electrode layer 1370 and the edge extension layer 1357, thereby improving the electromechanical coupling coefficient of the resonant device.

[0566] In addition, the edge portion 1351 and the extension portion form a reflective structure, which is located outside the first electrode layer 1340, thereby reflecting the sound waves in the resonance region, blocking leakage waves, and improving the Q value.

[0567] In this embodiment, the material of the substrate 1310 includes but is not limited to at least one of the following: silicon, silicon carbide, glass, gallium arsenide, gallium nitride, and ceramic.

[0568] In this embodiment, the material of the intermediate layer 1320 includes, but is not limited to, at least one of the following: a polymer, an insulating dielectric, and polysilicon. In this embodiment, the polymer includes, but is not limited to, at least one of the following: benzocyclobutene (i.e., BCB), a photosensitive epoxy resin photoresist (e.g., SU-8), and polyimide. In this embodiment, the insulating dielectric includes, but is not limited to, at least one of the following: aluminum nitride, silicon dioxide, silicon nitride, and titanium oxide.

[0569] In this embodiment, the material of the first electrode layer 1340 includes but is not limited to at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0570] In this embodiment, the edge portion 1351 includes an edge surrounding layer, which is located in the cavity 1330 and is electrically connected to the first electrode layer 1340; and an edge supporting layer, which is located in the cavity 1330 and on the edge surrounding layer, and is connected to the first electrode layer 1340, and the edge surrounding layer and the edge supporting layer overlap.

[0571] In this embodiment, the material of the edge surrounding layer is different from the material of the edge supporting layer. In another embodiment, the material of the edge surrounding layer is the same as the material of the edge supporting layer.

[0572] In this embodiment, the material of the edge surrounding layer comprises metal, and the material of the edge support layer comprises a non-metallic material. In another embodiment, the material of the edge surrounding layer comprises metal, and the medium of the edge support layer comprises air, i.e., an air layer. In another embodiment, the material of the edge surrounding layer comprises metal, and the medium of the edge support layer comprises vacuum, i.e., a vacuum layer. In another embodiment, the material of the edge surrounding layer comprises metal, and the material of the edge support layer comprises metal.

[0573] In this embodiment, the thickness of the extension portion is equal to the thickness of the edge portion 1351 .

[0574] In this embodiment, the material of the edge extension layer 1353 includes metal. In this embodiment, the material of the edge extension layer 1353 includes, but is not limited to, at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0575] In this embodiment, the dielectric of the composite support layer 1355 comprises a non-metallic material. In this embodiment, the dielectric of the composite support layer 1355 includes, but is not limited to, at least one of the following: silicon dioxide, silicon oxycarbide, silicon oxyfluoride, or a polymer. The polymer includes, but is not limited to, at least one of the following: benzocyclobutene (i.e., BCB), a photosensitive epoxy resin photoresist (e.g., SU-8), or polyimide. In another embodiment, the dielectric of the first composite support layer of the extension below the piezoelectric layer can be a vacuum, i.e., a vacuum layer. In another embodiment, the dielectric of the first composite support layer of the extension below the piezoelectric layer can be air, i.e., an air layer.

[0576] In this embodiment, the thickness of the composite support layer 1355 is greater than the thickness of the edge support layer. In another embodiment, the thickness of the first composite support layer of the extension portion is equal to the thickness of the edge support layer of the edge portion. In another embodiment, the thickness of the first composite support layer of the extension portion is less than the thickness of the edge support layer of the edge portion.

[0577] In this embodiment, the material of the edge extension layer 1357 includes metal. In this embodiment, the material of the edge extension layer 1357 includes, but is not limited to, at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0578] In this embodiment, the dielectric of the composite support layer 1359 comprises a non-metallic material. In this embodiment, the dielectric of the composite support layer 1359 includes, but is not limited to, at least one of the following: silicon dioxide, silicon oxycarbide, silicon oxyfluoride, or a polymer. The polymer includes, but is not limited to, at least one of the following: benzocyclobutene (i.e., BCB), a photosensitive epoxy resin photoresist (e.g., SU-8), or polyimide. In another embodiment, the dielectric of the second composite support layer of the extension below the piezoelectric layer may be a vacuum, i.e., a vacuum layer. In another embodiment, the dielectric of the second composite support layer of the extension below the piezoelectric layer may be air, i.e., an air layer.

[0579] In this embodiment, the thickness of the composite support layer 1359 is greater than the thickness of the edge support layer. In another embodiment, the thickness of the second composite support layer in the extension portion is equal to the thickness of the edge support layer in the edge portion. In another embodiment, the thickness of the second composite support layer in the extension portion is less than the thickness of the edge support layer in the edge portion.

[0580] In this embodiment, the edge extension layer 1353 and the edge extension layer 1357 have no overlapping portion. In this embodiment, the edge extension layer 1353 and the edge extension layer 1357 are located on both sides of the first electrode layer 1340.

[0581] In this embodiment, the piezoelectric layer 1360 is a flat layer and also covers the upper surface of the intermediate layer 1320. In this embodiment, the material of the piezoelectric layer 1360 includes, but is not limited to, at least one of the following: aluminum nitride, aluminum nitride alloy, gallium nitride, zinc oxide, lithium tantalate, lithium niobate, lead zirconate titanate, or lead magnesium niobate-lead titanate.

[0582] In this embodiment, the piezoelectric layer 1360 includes a plurality of crystal grains, including a first crystal grain and a second crystal grain, wherein the first crystal grain and the second crystal grain are any two crystal grains of the plurality of crystal grains. Those skilled in the art will appreciate that crystal orientations, crystal planes, and the like of crystal grains can be represented based on a coordinate system.

[0583] In this embodiment, the first grain can be represented based on a first three-dimensional coordinate system, and the second grain can be represented based on a second three-dimensional coordinate system, wherein the first three-dimensional coordinate system includes at least a first coordinate axis along the first direction and a third coordinate axis along the third direction, and the second three-dimensional coordinate system includes at least a second coordinate axis along the second direction and a fourth coordinate axis along the fourth direction, wherein the first coordinate axis corresponds to the height of the first grain, and the second coordinate axis corresponds to the height of the second grain.

[0584] In this embodiment, the first direction and the second direction are the same or opposite. It should be noted that the first direction and the second direction are the same means that the angle between the vector along the first direction and the vector along the second direction is within a range of 0 degrees to 5 degrees; the first direction and the second direction are opposite means that the angle between the vector along the first direction and the vector along the second direction is within a range of 175 degrees to 180 degrees.

[0585] In another embodiment, the first three-dimensional coordinate system is an ac three-dimensional coordinate system, wherein the first coordinate axis is the first c-axis and the third coordinate axis is the first a-axis; the second three-dimensional coordinate system is an ac three-dimensional coordinate system, wherein the second coordinate axis is the second c-axis and the fourth coordinate axis is the second a-axis, wherein the first c-axis and the second c-axis point in the same or opposite directions.

[0586] In another embodiment, the first three-dimensional coordinate system further includes a fifth coordinate axis along a fifth direction, and the second three-dimensional coordinate system further includes a sixth coordinate axis along a sixth direction. In another embodiment, the first direction and the second direction are the same or opposite, and the third direction and the fourth direction are the same or opposite. It should be noted that the third direction and the fourth direction are the same means that the angle between the vector along the third direction and the vector along the fourth direction ranges from 0 degrees to 5 degrees; the third direction and the fourth direction are opposite means that the angle between the vector along the third direction and the vector along the fourth direction ranges from 175 degrees to 180 degrees.

[0587] In another embodiment, the first 3D coordinate system is an xyz 3D coordinate system, wherein the first coordinate axis is the first z-axis, the third coordinate axis is the first y-axis, and the fifth coordinate axis is the first x-axis; and the second 3D coordinate system is an xyz 3D coordinate system, wherein the second coordinate axis is the second z-axis, the fourth coordinate axis is the second y-axis, and the sixth coordinate axis is the second x-axis. In another embodiment, the first z-axis and the second z-axis point in the same direction, and the first y-axis and the second y-axis point in the same direction. In another embodiment, the first z-axis and the second z-axis point in opposite directions, and the first y-axis and the second y-axis point in opposite directions. In another embodiment, the first z-axis and the second z-axis point in the same direction, and the first y-axis and the second y-axis point in opposite directions. In another embodiment, the first z-axis and the second z-axis point in the same direction, and the first y-axis and the second y-axis point in opposite directions. In another embodiment, the first z-axis and the second z-axis point in opposite directions, and the first y-axis and the second y-axis point in the same direction.

[0588] In this embodiment, the piezoelectric layer 1360 includes a plurality of crystal grains, and the half-peak width of the rocking curve of the crystal formed by the plurality of crystal grains is less than 2.5 degrees.

[0589] It should be noted that forming the piezoelectric layer 1360 on a plane can prevent the piezoelectric layer 1360 from including grains with obvious turns, thereby improving the electromechanical coupling coefficient of the resonant device and the Q value of the resonant device.

[0590] In this embodiment, the material of the electrode layer 1370 includes but is not limited to at least one of the following: molybdenum, ruthenium, tungsten, platinum, iridium, aluminum, and beryllium.

[0591] In this embodiment, the portion of the first electrode layer 1340 that overlaps with the electrode layer 1370 is located in the cavity 1330 ; the portion of the electrode 1370 that overlaps with the electrode 1340 is located above the cavity 1330 and corresponds to the cavity 1330 .

[0592] In this embodiment, the width of the first overlapping portion is equal to the width of the edge portion 1351 , and the width of the second overlapping portion is equal to the width of the edge portion 1351 .

[0593] Figure 50 FIG. 1 is a schematic top view of a bulk acoustic wave resonator device 1300 according to an embodiment of the present invention.

[0594] like Figure 50 As shown, in this embodiment, the edge portion 1351 is annular. In this embodiment, the edge portion 1351 is octagonal. It should be noted that edge portions of other shapes known to those skilled in the art, such as hexagons, pentagons, etc., can also be applied to embodiments of the present invention. In this embodiment, the extension portion is adjacent to the six sides of the edge portion 1351, wherein the edge extension layer 1353 is adjacent to the first side, the second side and the third side, and the edge extension layer 1357 is adjacent to the fourth side, the fifth side and the sixth side, the first side, the second side and the third side are located at the first end of the first electrode layer 1340, and the fourth side, the fifth side and the sixth side are located at the second end of the first electrode layer 1340.

[0595] like Figure 55As shown, an embodiment of the present invention provides a bulk acoustic wave resonator device 1400 including: a substrate 1410; an intermediate layer 1420, located on the substrate 1410, wherein the upper surface side of the intermediate layer 1420 includes a cavity 1430 and a groove 1431, wherein the groove 1431 is located on one side of the cavity 1430 and communicates with the cavity 1430, and the depth of the groove 1431 is less than the depth of the cavity 1430; a first electrode layer 1440, located in the cavity 1430; a first composite structure 1450, wherein the first composite structure 1450 includes: a first edge portion 1451, located in the cavity 1430, and the first electrode layer 1440 is provided with a plurality of grooves 1431, 1440 ... 0 is located on the inner side of the first edge portion 1451 (i.e., facing the side of the central axis of the BAW resonator 1400); a first extension portion (unlabeled) is located on the outer side of the first edge portion 1451 (i.e., facing the side opposite to the central axis of the BAW resonator 1400), a first end of the first extension portion is connected to the first edge portion 1451, and a second end of the first extension portion opposite to the first end is located in the groove 1431, wherein the depth of the groove 1431 is equal to the thickness of the first extension portion, and the first extension portion includes a first edge extension layer 1453, which is electrically connected to the first edge portion 1451 and the first composite support layer. 1455, located on the first edge extension layer 1453, connected to the first edge portion 1451, the first composite support layer 1455 and the first edge extension layer 1453 overlap; a piezoelectric layer 1460, located on the first electrode layer 1440, the first edge portion 1451, the first composite support layer 1455 and the intermediate layer 1420, covering the cavity 1430, wherein the piezoelectric layer 1460 includes a first side 1461 and a second side 1463 opposite to the first side 1461, the first electrode layer 1440, the first composite structure 1450 and the intermediate layer 1420 are located on the first side 1461; a second an electrode layer 1470 located on the second side 1463 and on the piezoelectric layer 1460; the first edge portion 1451 and the second electrode layer 1470 have an overlapping portion; the first edge extension layer 1453 and the first composite support layer 1455 have a first overlapping portion with the second electrode layer 1470; a second composite structure 1480 comprising: a second edge portion 1481 located on the second side 1463 and on the piezoelectric layer 1460; the second electrode layer 1470 located inward of the second edge portion 1481; and an overlapping portion between the second edge portion 1481 and the first electrode layer 1440.A second extension portion (not labeled) is located on second side 1463, on piezoelectric layer 1460, outside of and connected to second edge portion 1481. The second extension portion includes a second edge extension layer 1483, located on second side 1463, above piezoelectric layer 1460, and electrically connected to second edge portion 1481, and a second composite support layer 1485, located on second side 1463, on piezoelectric layer 1460, between piezoelectric layer 1460 and second edge extension layer 1483, and connected to second edge portion 1481. The second composite support layer 1485 overlaps with the second edge extension layer 1483, and the second edge extension layer 1483 and the second composite support layer 1485 form a second overlapping portion with the first electrode layer 1440.

[0596] It should be noted that the first composite support layer 1455 thickens the medium between the second electrode layer 1470 and the first edge extension layer 1453, reducing the edge capacitance between the second electrode layer 1470 and the first edge extension layer 1453, and the second composite support layer 1485 thickens the medium between the first electrode layer 1440 and the second edge extension layer 1483, reducing the edge capacitance between the first electrode layer 1440 and the second edge extension layer 1483, thereby improving the electromechanical coupling coefficient of the resonant device.

[0597] In addition, the first edge portion 1451 and the first extension portion form a first reflection structure, which is located on the outside of the first electrode layer 1440; the second edge portion 1481 and the second extension portion form a second reflection structure, which is...

Claims

1. A bulk acoustic wave resonator device, characterized in that: include: a first layer, the first layer comprising a cavity; a first electrode layer, wherein the first electrode layer is located in the cavity; a piezoelectric layer, located on the first electrode layer and covering the cavity, the piezoelectric layer comprising a first side and a second side perpendicular to the first side, the first electrode layer being located on the first side; a second electrode layer, located on the second side and on the piezoelectric layer, wherein a portion of the second electrode layer overlapping with the first electrode layer is located above the cavity and corresponds to the cavity; as well as a first composite structure, located on the first side and contacting the piezoelectric layer, the first composite structure surrounding the first electrode layer, the first composite structure comprising: a first edge portion, located in the cavity, the first edge portion connected to the first electrode layer and surrounding the first electrode layer, the first edge portion and the second electrode layer having an overlapping portion; a first extension portion, connected to the first edge portion, a first end of the first extension portion close to the first electrode layer being located in the cavity, and a second end of the first extension portion, facing away from the first electrode layer and opposite to the first end in a horizontal direction, being embedded in the first layer; a third extension portion, located in the cavity, connected to the first edge portion; the first extension portion and the third extension portion being located at opposite ends of the first electrode layer in a horizontal direction; Among them, the first extension part includes a first edge extension layer and a first supporting layer, the first edge extension layer, the first supporting layer and the second electrode layer have a first overlapping part, and the first supporting layer is located between the piezoelectric layer and the first edge extension layer, and is used to reduce the edge capacitance; the third extension part includes a third edge extension layer and a third supporting layer, the third edge extension layer, the third supporting layer and the second electrode layer have a third overlapping part, the third overlapping part matches the first overlapping part, and the third supporting layer is located between the piezoelectric layer and the third edge extension layer.

2. The bulk acoustic wave resonator device according to claim 1, wherein The material of the first edge extension layer includes metal; the medium of the first support layer includes one of the following: non-metallic material, air, and vacuum; the material of the third edge extension layer includes metal; the medium of the third support layer includes one of the following: non-metallic material, air, and vacuum.

3. The bulk acoustic wave resonator device according to claim 1, wherein The first edge portion includes a first edge surrounding layer. The material of the first edge surrounding layer includes metal. The first edge surrounding layer is connected to the first electrode layer. The first edge surrounding layer is also connected to the first edge extension layer.

4. The bulk acoustic wave resonator device according to claim 1, wherein The width of the first overlapping portion is equal to the width of the first edge portion, and the width of the third overlapping portion is equal to the width of the first edge portion.

5. The bulk acoustic wave resonator device according to claim 1, wherein The thickness of the first edge portion is equal to the sum of the thicknesses of the first edge extension layer and the first supporting layer, and the thickness of the first edge portion is equal to the sum of the thicknesses of the third edge extension layer and the third supporting layer.

6. The bulk acoustic wave resonator device according to claim 1, wherein: The first layer includes: an intermediate layer, the intermediate layer includes the cavity, wherein a material of the intermediate layer includes at least one of the following: a polymer, an insulating dielectric, and polysilicon.

7. A method for forming a bulk acoustic wave resonator device, characterized in that: include: forming a piezoelectric layer, the piezoelectric layer comprising a first side and a second side perpendicular to the first side; forming a first electrode layer located on the first side; forming a first layer located on the first side, wherein the first electrode layer is located between the first layer and the piezoelectric layer; forming a second electrode layer located on the second side; forming a first composite structure located on the first side and contacting the piezoelectric layer, wherein the first composite structure surrounds the first electrode layer, and forming the first composite structure includes: forming a first edge portion, wherein the first edge portion is connected to the first electrode layer and surrounds the first electrode layer, and the first edge portion and the second electrode layer have an overlapping portion; forming a first extension portion, which is connected to the first edge portion, wherein a second end of the first extension portion, which is away from the first electrode layer, is embedded in the first layer; and forming a third extension portion, which is connected to the first edge portion; wherein the first extension portion and the third extension portion are located at opposite ends of the first electrode layer in a horizontal direction. Wherein, forming the first extension portion includes forming a first edge extension layer and a first supporting layer, the first edge extension layer, the first supporting layer, and the second electrode layer having a first overlapping portion, the first supporting layer being located between the piezoelectric layer and the first edge extension layer, and being used to reduce edge capacitance; forming the third extension portion includes forming a third edge extension layer and a third supporting layer, the third edge extension layer, the third supporting layer, and the second electrode layer having a third overlapping portion, the third overlapping portion matching the first overlapping portion, and the third supporting layer being located between the piezoelectric layer and the third edge extension layer; and A cavity is formed and located on the first side, the cavity is located between the first layer and the piezoelectric layer, embedded in the first layer, the piezoelectric layer covers the cavity, the first electrode layer is located in the cavity, the first edge portion is located in the cavity, the first extension portion is close to the first electrode layer and the first end opposite to the second end in the horizontal direction is located in the cavity, and the third extension portion is located in the cavity.

8. The method for forming a bulk acoustic wave resonator device according to claim 7, wherein: Forming the first layer includes: forming a sacrificial layer on the first side of the piezoelectric layer, the sacrificial layer covering the first electrode layer; forming a first bonding layer on the first side of the piezoelectric layer, the first bonding layer covering the sacrificial layer and the first electrode layer; providing a substrate; forming a second bonding layer on one side of the substrate; bonding the first bonding layer and the second bonding layer to form an intermediate layer, the substrate is located on the first side, and the intermediate layer is located between the substrate and the piezoelectric layer.

9. The method for forming a bulk acoustic wave resonator device according to claim 7, wherein: Also includes: A transition substrate is provided; and the piezoelectric layer is formed based on the transition substrate, wherein the transition substrate is located on the second side.

10. The method for forming a bulk acoustic wave resonator device according to claim 9, wherein: Also includes: After forming the first layer, the transition substrate is removed; after removing the transition substrate, the second electrode layer is formed.

11. The method for forming a bulk acoustic wave resonator device according to claim 8, wherein: Forming the cavity includes removing the sacrificial layer, wherein removing the sacrificial layer includes wet etching the sacrificial layer.

12. The method for forming a bulk acoustic wave resonator device according to claim 7, wherein: Forming the first edge portion includes forming a first edge surrounding layer, wherein a material of the first edge surrounding layer includes metal, the first edge surrounding layer is connected to the first electrode layer, and the first edge surrounding layer is further connected to the first edge extension layer.

13. The method for forming a bulk acoustic wave resonator device according to claim 7, wherein: The width of the first overlapping portion is equal to the width of the first edge portion, and the width of the third overlapping portion is equal to the width of the first edge portion.

14. The method for forming a bulk acoustic wave resonator device according to claim 7, wherein: The thickness of the first edge portion is equal to the sum of the thicknesses of the first edge extension layer and the first supporting layer, and the thickness of the first edge portion is equal to the sum of the thicknesses of the third edge extension layer and the third supporting layer.

15. A bulk acoustic wave resonance device, characterized in that: include: a first layer, the first layer comprising a cavity; a first electrode layer, wherein at least one end of the first electrode layer is located in the cavity; a piezoelectric layer, located on the first electrode layer and covering the cavity, the piezoelectric layer comprising a first side and a second side perpendicular to the first side, the first electrode layer being located on the first side; a second electrode layer, located on the second side and on the piezoelectric layer, wherein a portion of the second electrode layer overlapping with the first electrode layer is located above the cavity and corresponds to the cavity; as well as a second composite structure, located on the second side and contacting the piezoelectric layer, the second composite structure surrounding the second electrode layer, the second composite structure comprising: a second edge portion, connected to and surrounding the second electrode layer, the second edge portion and the first electrode layer having an overlapping portion; a second extension portion, connected to the second edge portion; and a fourth extension portion, connected to the second edge portion; the second extension portion and the fourth extension portion being located at opposite ends of the second electrode layer in a horizontal direction; Among them, the second extension part includes a second edge extension layer and a second supporting layer, the second edge extension layer and the second supporting layer and the first electrode layer have a second overlapping portion, and the second supporting layer is located between the piezoelectric layer and the second edge extension layer, and is used to reduce the edge capacitance; the fourth extension part includes a fourth edge extension layer and a fourth supporting layer, the fourth edge extension layer and the fourth supporting layer and the first electrode layer have a fourth overlapping portion, the fourth overlapping portion matches the second overlapping portion, and the fourth supporting layer is located between the piezoelectric layer and the fourth edge extension layer.

16. The bulk acoustic wave resonator device according to claim 15, wherein: The material of the second edge extension layer includes metal; the medium of the second support layer includes one of the following: non-metallic material, air, and vacuum; the material of the fourth edge extension layer includes metal; the medium of the fourth support layer includes one of the following: non-metallic material, air, and vacuum.

17. The bulk acoustic wave resonator device according to claim 15, wherein: The second edge portion includes a second edge surrounding layer. The material of the second edge surrounding layer includes metal. The second edge surrounding layer is connected to the second electrode layer. The second edge surrounding layer is also connected to the second edge extension layer.

18. The bulk acoustic wave resonator device according to claim 15, wherein: The width of the second overlapping portion is equal to the width of the second edge portion, and the width of the fourth overlapping portion is equal to the width of the second edge portion.

19. The bulk acoustic wave resonator device according to claim 15, wherein: The thickness of the second edge portion is equal to the sum of the thicknesses of the second edge extension layer and the second supporting layer, and the thickness of the second edge portion is equal to the sum of the thicknesses of the fourth edge extension layer and the fourth supporting layer.

20. The bulk acoustic wave resonator device according to claim 15, wherein: The first layer includes: an intermediate layer, the intermediate layer includes the cavity, wherein a material of the intermediate layer includes at least one of the following: a polymer, an insulating dielectric, and polysilicon.

21. A method for forming a bulk acoustic wave resonator device, characterized in that: include: forming a piezoelectric layer, the piezoelectric layer comprising a first side and a second side perpendicular to the first side; forming a first electrode layer located on the first side; forming a first layer located on the first side, wherein the first electrode layer is located between the first layer and the piezoelectric layer and is embedded in the first layer; forming a second electrode layer located on the second side; forming a second composite structure located on the second side and contacting the piezoelectric layer, the second composite structure surrounding the second electrode layer, the forming of the second composite structure comprising: forming a second edge portion connected to and surrounding the second electrode layer, the second edge portion and the first electrode layer having an overlapping portion; forming a second extension portion connected to the second edge portion; and forming a fourth extension portion connected to the second edge portion; the second extension portion and the fourth extension portion being located at opposite ends of the second electrode layer in a horizontal direction; Wherein, forming the second extension portion includes forming a second edge extension layer and a second supporting layer, the second edge extension layer and the second supporting layer have a second overlapping portion with the first electrode layer, and the second supporting layer is located between the piezoelectric layer and the second edge extension layer, and is used to reduce edge capacitance; forming the fourth extension portion includes forming a fourth edge extension layer and a fourth supporting layer, the fourth edge extension layer and the fourth supporting layer have a fourth overlapping portion with the first electrode layer, the fourth overlapping portion matches the second overlapping portion, and the fourth supporting layer is located between the piezoelectric layer and the fourth edge extension layer; and A cavity is formed on the first side, the cavity is located between the first layer and the piezoelectric layer, and is embedded in the first layer. The piezoelectric layer covers the cavity, and at least one end of the first electrode layer is located in the cavity.

22. The method for forming a bulk acoustic wave resonator device according to claim 21, wherein: Forming the first layer includes: forming a sacrificial layer on the first side of the piezoelectric layer, the sacrificial layer covering a portion of the first electrode layer, and the sacrificial layer covering at least one end of the first electrode layer; forming a first bonding layer on the first side of the piezoelectric layer, the first bonding layer covering the sacrificial layer and the first electrode layer; providing a substrate; forming a second bonding layer on one side of the substrate; bonding the first bonding layer and the second bonding layer to form an intermediate layer, the substrate being located on the first side, and the intermediate layer being located between the substrate and the piezoelectric layer.

23. The method for forming a bulk acoustic wave resonator device according to claim 21, wherein: Also includes: A transition substrate is provided; and the piezoelectric layer is formed based on the transition substrate, wherein the transition substrate is located on the second side.

24. The method for forming a bulk acoustic wave resonator device according to claim 23, wherein: Also includes: After forming the first layer, the transition substrate is removed; after removing the transition substrate, the second electrode layer is formed.

25. The method for forming a bulk acoustic wave resonator device according to claim 22, wherein: Forming the cavity includes removing the sacrificial layer, wherein removing the sacrificial layer includes wet etching the sacrificial layer.

26. The method for forming a bulk acoustic wave resonator device according to claim 21, wherein: Forming the second edge portion includes forming a second edge surrounding layer, wherein the material of the second edge surrounding layer includes metal, the second edge surrounding layer is connected to the second electrode layer, and the second edge surrounding layer is further connected to the second edge extension layer.

27. The method for forming a bulk acoustic wave resonator device according to claim 21, wherein: The width of the second overlapping portion is equal to the width of the second edge portion, and the width of the fourth overlapping portion is equal to the width of the second edge portion.

28. The method for forming a bulk acoustic wave resonator device according to claim 21, wherein: The thickness of the second edge portion is equal to the sum of the thicknesses of the second edge extension layer and the second supporting layer, and the thickness of the second edge portion is equal to the sum of the thicknesses of the fourth edge extension layer and the fourth supporting layer.

29. A filtering device, characterized in that: include: At least one BAW resonator device according to any one of claims 1 to 6, 15 to 20.

30. A radio frequency front-end device, characterized in that: include: A power amplifying device and at least one filtering device as claimed in claim 29; The power amplifying device is connected to the filtering device.

31. A radio frequency front-end device, characterized in that: include: A low noise amplifier device and at least one filtering device as claimed in claim 29; The low-noise amplifying device is connected to the filtering device.

32. A radio frequency front-end device, characterized in that: include: A multiplexing device comprising at least one filtering device as claimed in claim 29.

Images