A thin film bulk acoustic wave resonator chip structure and manufacturing method

Abstract

The disclosed embodiment provides a thin film bulk acoustic wave resonator chip structure and a manufacturing method. The structure includes: a first substrate and a piezoelectric layer, a first metal layer and a fourth metal layer constituting a resonator unit; the first metal layer is divided into a first metal layer first electrode portion, a first metal layer second electrode connecting portion and a first metal layer resonator peripheral portion by an isolation groove; the second metal layer includes a second metal layer first portion, a second metal layer second portion and a second metal layer third portion; the third metal layer first portion is located on a side of the second metal layer first portion away from the first metal layer; the third metal layer second portion is located on a side of the second metal layer second portion away from the first metal layer; the third metal layer third portion is located on a side of the second metal layer third portion away from the first metal layer; the sum of the heights of the second metal layer and the third metal layer determines the height of the first cavity between the first substrate and the resonator unit.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to a thin film bulk acoustic wave resonator chip structure and a manufacturing method. Background Art

[0002] Film Bulk Acoustic Resonator (FBAR) converts electrical energy into sound waves to form resonance through the inverse piezoelectric effect of piezoelectric film. This resonance technology can be used to make advanced components such as thin film frequency shaping devices. Film Bulk Acoustic Resonator (FBAR) acoustic wave devices have the characteristics of small size, low cost, high quality factor (Q), strong power handling capacity, high frequency (up to 1-10GHz) and compatibility with IC technology.

[0003] Current filter products including thin film bulk acoustic resonators have a technical problem of poor heat dissipation. Summary of the invention

[0004] In view of this, the present disclosure provides a thin film bulk acoustic wave resonator chip structure and a manufacturing method to improve the heat dissipation performance of the thin film bulk acoustic wave resonator chip structure.

[0005] The present disclosure provides a thin film bulk acoustic wave resonator chip structure, comprising: a first substrate;

[0006] A piezoelectric layer is located on one side of the first substrate; the piezoelectric layer comprises an upper surface and a lower surface that are arranged opposite to each other; the lower surface of the piezoelectric layer is a surface facing the first substrate;

[0007] A first metal layer is located on the lower surface of the piezoelectric layer, the first metal layer is provided with an isolation groove, the bottom of the isolation groove exposes the piezoelectric layer, the first metal layer is divided into a first metal layer first electrode portion, a first metal layer second electrode connecting portion and a first metal layer resonator peripheral portion by the isolation groove, and the first metal layer resonator peripheral portion encloses and surrounds the first metal layer first electrode portion and the first metal layer second electrode connecting portion;

[0008] a first passivation layer, located on a side of the first metal layer away from the piezoelectric layer; the isolation groove also penetrates the first passivation layer; a contact hole is provided in the first passivation layer, the contact hole comprises a first contact hole portion, a second contact hole portion and a third contact hole portion, the bottom of the first contact hole portion exposes the first electrode portion of the first metal layer, the bottom of the second contact hole portion exposes the second electrode connecting portion of the first metal layer, and the bottom of the third contact hole portion exposes the peripheral portion of the resonator of the first metal layer;

[0009] The second metal layer is located on a side of the first passivation layer away from the first metal layer, and includes a first portion of the second metal layer, a second portion of the second metal layer, and a third portion of the second metal layer; the first portion of the second metal layer is connected to the first electrode portion of the first metal layer through the first portion of the contact hole; the second portion of the second metal layer is connected to the second electrode connecting portion of the first metal layer through the second portion of the contact hole; and the third portion of the second metal layer is connected to the resonator peripheral portion of the first metal layer through the third portion of the contact hole;

[0010] a third metal layer, located on one side of the first substrate, comprising a first portion of the third metal layer, a second portion of the third metal layer and a third portion of the third metal layer; the first portion of the third metal layer is located on a side of the first portion of the second metal layer away from the first metal layer; the second portion of the third metal layer is located on a side of the second portion of the second metal layer away from the first metal layer; the third portion of the third metal layer is located on a side of the third portion of the second metal layer away from the first metal layer;

[0011] a fourth metal layer, located on the upper surface of the piezoelectric layer;

[0012] The piezoelectric layer, the first metal layer and the fourth metal layer constitute a resonator unit, and the sum of the heights of the second metal layer and the third metal layer determines the height of a first cavity between the first substrate and the resonator unit.

[0013] The present disclosure provides a method for manufacturing a thin film bulk acoustic wave resonator chip structure, comprising:

[0014] obtaining a temporary substrate;

[0015] forming a buffer layer on one side of the temporary substrate;

[0016] A piezoelectric layer, a first metal layer and a first passivation layer are sequentially formed on a side of the buffer layer away from the temporary substrate; the piezoelectric layer comprises an upper surface and a lower surface arranged opposite to each other; the first metal layer is located on the lower surface of the piezoelectric layer; and the first passivation layer is located on a side of the first metal layer away from the piezoelectric layer;

[0017] An isolation groove is formed in the first passivation layer and the first metal layer, the bottom of the isolation groove exposes the piezoelectric layer, the first metal layer is divided into a first metal layer first electrode portion, a first metal layer second electrode connecting portion and a first metal layer resonator peripheral portion by the isolation groove, and the first metal layer resonator peripheral portion closes and surrounds the first metal layer first electrode portion and the first metal layer second electrode connecting portion;

[0018] A contact hole is formed in the first passivation layer, the contact hole comprising a first contact hole portion, a second contact hole portion and a third contact hole portion, the bottom of the first contact hole portion exposes the first electrode portion of the first metal layer, the bottom of the second contact hole portion exposes the second electrode connecting portion of the first metal layer, and the bottom of the third contact hole portion exposes the resonator peripheral portion of the first metal layer;

[0019] A second metal layer is formed on a side of the first passivation layer away from the first metal layer, the second metal layer comprising a first portion of the second metal layer, a second portion of the second metal layer, and a third portion of the second metal layer; the first portion of the second metal layer is connected to the first electrode portion of the first metal layer through the first portion of the contact hole; the second portion of the second metal layer is connected to the second electrode connecting portion of the first metal layer through the second portion of the contact hole; the third portion of the second metal layer is connected to the resonator peripheral portion of the first metal layer through the third portion of the contact hole;

[0020] Obtaining a first substrate, wherein a third metal layer is formed on one side of the first substrate, and the third metal layer includes a third metal layer first portion, a third metal layer second portion, and a third metal layer third portion;

[0021] The third metal layer and the second metal layer are connected by a bonding process; wherein the first portion of the third metal layer is located on a side of the first portion of the second metal layer away from the first metal layer; the second portion of the third metal layer is located on a side of the second portion of the second metal layer away from the first metal layer; the third portion of the third metal layer is located on a side of the third portion of the second metal layer away from the first metal layer;

[0022] removing the temporary substrate;

[0023] removing the buffer layer;

[0024] forming a fourth metal layer on the upper surface of the piezoelectric layer;

[0025] The piezoelectric layer, the first metal layer and the fourth metal layer constitute a resonator unit, and the sum of the heights of the second metal layer and the third metal layer determines the height of a first cavity between the first substrate and the resonator unit.

[0026] In the thin film bulk acoustic wave resonator chip structure and manufacturing method provided by the embodiments of the present disclosure, the piezoelectric layer, the first metal layer and the fourth metal layer constitute the resonator unit, and the sum of the heights of the second metal layer and the third metal layer determines the height of the first cavity between the first substrate and the resonator unit. The first substrate and the resonator unit are bonded and connected by metal-metal bonding of the second metal layer and the third metal layer. Structurally, there is a large-area metal bonding layer between the first substrate and the piezoelectric layer, and the first substrate can flexibly select a material with good thermal conductivity. And the sum of the heights of the second metal layer and the third metal layer determines the height of the first cavity between the first substrate and the resonator unit, while enhancing the supporting capacity, forming a cavity structure that improves the electrical performance of the resonator unit.

[0027] It should be noted that the above description of the structure and manufacturing method of the surface acoustic wave filter chip and the related description to be described below are merely exemplary and explanatory and are not intended to limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings of the embodiments will be described in detail one by one below. It should be noted that the drawings in the following description only relate to the embodiments of the present disclosure, but not to limit the present disclosure. It must also be pointed out that the various features shown in the drawings are not drawn to scale. In fact, for the sake of clarity, it is sometimes necessary to arbitrarily increase or decrease the size of various features.

[0029] Figure 1 : A plan view of a thin film bulk acoustic wave resonator chip structure.

[0030] Figure 2 : A cross-sectional schematic diagram of a thin film bulk acoustic wave resonator chip structure, Figure 1 The AA′ section is shown in a plan view from above.

[0031] Figure 3 : A cross-sectional schematic diagram of a thin film bulk acoustic wave resonator chip structure, Figure 1 The AA′ section is shown in a plan view from above.

[0032] Figure 4 : A cross-sectional schematic diagram of a thin film bulk acoustic wave resonator chip structure, Figure 1 The AA′ section is shown in a plan view from above.

[0033] Figure 5 : A cross-sectional schematic diagram of a thin film bulk acoustic wave resonator chip structure, Figure 1 The AA′ section is shown in a plan view from above.

[0034] Figure 6: A cross-sectional schematic diagram of a thin film bulk acoustic wave resonator chip structure, Figure 1 The AA′ section is shown in a plan view from above.

[0035] Figure 7 : A cross-sectional schematic diagram of a thin film bulk acoustic wave resonator chip structure, Figure 1 The AA′ section is shown in a plan view from above.

[0036] Figure 8 :and Figure 2 and Figure 3 A process flow chart related to the manufacturing method corresponding to the thin film bulk acoustic wave resonator chip structure shown.

[0037] Figures 9 to 25 : Show Figure 8 The schematic cross-sectional view of each process step related to the manufacturing method corresponding to the thin film bulk acoustic wave resonator chip structure shown.

[0038] Fig.26 :and Figures 4 to 7 A process flow chart related to the manufacturing method corresponding to the thin film bulk acoustic wave resonator chip structure shown.

[0039] Figure 27 to Figure 28 : Show Fig.26 The schematic cross-sectional view of each process step related to the manufacturing method corresponding to the thin film bulk acoustic wave resonator chip structure shown.

[0040] Figures 1 to 28 This is a schematic diagram of the thin film bulk acoustic wave resonator chip structure and manufacturing method involved in the present disclosure, and the figure numbers are as follows:

[0041] 200: First substrate.

[0042] 120: Piezoelectric layer.

[0043] 130 : a first metal layer, including a first metal layer first electrode portion 130 a , a first metal layer second electrode connecting portion 130 b and a first metal layer resonator peripheral portion 130 c .

[0044] 140: First passivation layer.

[0045] 150: Isolation slot.

[0046] 160 : contact hole, including a first contact hole portion 160 a , a second contact hole portion 160 b and a third contact hole portion 160 c .

[0047] 165: a second metal layer, including a second metal layer first portion 165a, a second metal layer second portion 165b and a second metal layer third portion 165c.

[0048] 220 : a third metal layer, including a third metal layer first portion 220 a , a third metal layer second portion 220 b and a third metal layer third portion 220 c .

[0049] 170: Fourth metal layer.

[0050] 180: Second passivation layer.

[0051] 185: a first through hole, comprising a first through hole first portion 185a, a first through hole second portion 185b and a first through hole third portion 185c.

[0052] 190 : a fifth metal layer, including a fifth metal layer first portion 190 a , a fifth metal layer second portion 190 b and a fifth metal layer third portion 190 c .

[0053] 210: First depression.

[0054] 300: Second substrate.

[0055] 310 : a sixth metal layer, including a sixth metal layer first portion 310 a , a sixth metal layer second portion 310 b and a sixth metal layer third portion 310 c .

[0056] 1000: First cavity.

[0057] 230: Second through hole.

[0058] 320: The third through hole.

[0059] 110: Buffer layer.

[0060] 100: Temporary substrate. DETAILED DESCRIPTION

[0061] In order to be able to understand the features and technical contents of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure is described in detail below in conjunction with the accompanying drawings. The attached drawings are for reference only and are not used to limit the embodiments of the present disclosure. In the following technical description, for the convenience of explanation, a full understanding of the disclosed embodiments is provided through multiple details. However, one or more embodiments can still be implemented without these details. In other cases, in order to simplify the drawings, well-known structures and devices can be simplified for display. And it should be noted that, in the absence of conflict, the embodiments in the embodiments of the present disclosure and the features in the embodiments can be combined with each other.

[0062] Figure 1 The figure shows a plan view of a thin film bulk acoustic wave resonator chip structure, and the position of the AA′ section is marked in the figure.

[0063] Figure 2 and Figure 3The following is a thin film bulk acoustic wave resonator chip structure embodiment (embodiment 1) corresponding to Figure 1 Schematic diagram of the AA′ section of the plan view shown.

[0064] The following combination Figure 1 and Figure 2 as well as Figure 3 As shown, the structural features of the thin film bulk acoustic wave resonator chip structure of the first embodiment are described in detail.

[0065] The thin film bulk acoustic wave resonator chip structure includes:

[0066] The first substrate 200 is made of any one of Si, glass, ceramic and silicon carbide. Preferably, the first substrate 200 is made of ceramic or silicon carbide. Ceramics and silicon carbide have excellent thermal conductivity and can improve the heat dissipation performance of the thin film bulk acoustic wave resonator chip structure.

[0067] The piezoelectric layer 120 is located on one side of the first substrate 200; the piezoelectric layer 120 includes an upper surface and a lower surface that are opposite to each other; the lower surface of the piezoelectric layer 120 is a surface facing the first substrate 200. Optionally, the piezoelectric layer 120 includes aluminum nitride (AlN) and / or scandium-doped aluminum nitride (ScAlN).

[0068] The first metal layer 130 is located on the lower surface of the piezoelectric layer 120. The first metal layer 130 is provided with an isolation groove 150. The bottom of the isolation groove 150 exposes the piezoelectric layer 120. The first metal layer 130 is divided into a first metal layer first electrode portion 130a, a first metal layer second electrode connecting portion 130b and a first metal layer resonator peripheral portion 130c by the isolation groove. The first metal layer resonator peripheral portion 130c encloses and surrounds the first metal layer first electrode portion 130a and the first metal layer second electrode connecting portion 130b. Optionally, the first metal layer 130 includes at least one of Mo, TiW, W and Ru.

[0069] The first passivation layer 140 is located on the side of the first metal layer 130 away from the piezoelectric layer 120; the isolation groove 150 also penetrates the first passivation layer 140; the first passivation layer 140 is provided with a contact hole 160, and the contact hole 160 includes a first contact hole portion 160a, a second contact hole portion 160b and a third contact hole portion 160c, the bottom of the first contact hole portion 160a exposes the first metal layer first electrode portion 130a, the bottom of the second contact hole portion 160b exposes the first metal layer second electrode connection portion 130b, and the bottom of the third contact hole portion 160c exposes the first metal layer resonator peripheral portion 130c. Optionally, the first passivation layer 140 includes at least one of AlN, SiC, SiO2 and SiN.

[0070] The second metal layer 165 is located on the side of the first passivation layer 140 away from the first metal layer 130, and includes a second metal layer first portion 165a, a second metal layer second portion 165b, and a second metal layer third portion 165c; the second metal layer first portion 165a is connected to the first metal layer first electrode portion 130a through the contact hole first portion 160a; the second metal layer second portion 165b is connected to the first metal layer second electrode connection portion 130b through the contact hole second portion 160b; the second metal layer third portion 165c is connected to the first metal layer resonator peripheral portion 130c through the contact hole third portion 160c. Optionally, the second metal layer 165 includes at least one of Ti, Cr, TiW, Al, Au, Cu, Ag, and Pt.

[0071] The third metal layer 220 is located on one side of the first substrate 200, and includes a third metal layer first portion 220a, a third metal layer second portion 220b, and a third metal layer third portion 220c; the third metal layer first portion 220a is located on the side of the second metal layer first portion 165a away from the first metal layer 130; the third metal layer second portion 220b is located on the side of the second metal layer second portion 165b away from the first metal layer 130; the third metal layer third portion 220c is located on the side of the second metal layer third portion 165c away from the first metal layer 130. Optionally, the third metal layer 220 includes at least one of Ti, Cr, TiW, Al, Au, Cu, Ag, and Pt, which is the same as the optional material of the second metal layer 165.

[0072] The fourth metal layer 170 is located on the upper surface of the piezoelectric layer 120. Optionally, the fourth metal layer 170 includes at least one of Mo, TiW, W, and Ru, which is the same as the optional material of the first metal layer 130.

[0073] The piezoelectric layer 120 , the first metal layer 130 and the fourth metal layer 170 constitute a resonator unit, and the sum of the heights of the second metal layer 165 and the third metal layer 220 determines the height of the first cavity 1000 between the first substrate 200 and the resonator unit.

[0074] Optional, such as Figure 2 and Figure 3 As shown, the FBAW resonator chip structure further includes a second passivation layer 180, which is located on a side of the fourth metal layer 170 away from the piezoelectric layer 120, and the second passivation layer 180 covers a portion of the surface of the fourth metal layer. Optionally, the second passivation layer 180 includes at least one of AlN, SiC, SiO2 and SiN, which is the same as the optional material of the first passivation layer 140.

[0075] Optional, such as Figure 2 and Figure 3As shown, the piezoelectric layer 120 is provided with a first through hole 185, including a first through hole first part 185a, a first through hole second part 185b and a first through hole third part 185c; the bottom of the first through hole first part 185a exposes the first metal layer first electrode part 130a, the bottom of the first through hole second part 185b exposes the first metal layer second electrode connecting part 130b, and the bottom of the first through hole third part 185c exposes the first metal layer resonator peripheral part 130c.

[0076] The thin film bulk acoustic wave resonator chip structure also includes a fifth metal layer 190, which is located on the upper surface of the piezoelectric layer 120, including a first part 190a of the fifth metal layer, a second part 190b of the fifth metal layer and a third part 190c of the fifth metal layer; the first end of the first part 190a of the fifth metal layer is connected to the first electrode part 130a of the first metal layer through the first through hole first part 185a, and the second end of the first part 190a of the fifth metal layer is located on the upper surface of the piezoelectric layer 120; the first end of the second part 190b of the fifth metal layer is connected to the second electrode connecting part 130b of the first metal layer through the first through hole second part 185b, and the second end of the second part 190b of the fifth metal layer is connected to the fourth metal layer 170; the first end of the third part 190c of the fifth metal layer is adjacent to the first metal layer resonator peripheral part 130c through the first through hole third part 185c, and the second end of the third part 190c of the fifth metal layer is located on the upper surface of the piezoelectric layer 120. Optionally, the fifth metal layer 190 includes at least one of Ti, Cr, TiW, Al, Au, Cu, Ag and Pt, which is the same as the optional material of the second metal layer 165 .

[0077] In the technical solution of the embodiment of the present disclosure, the piezoelectric layer 120, the first metal layer 130 and the fourth metal layer 170 constitute a resonator unit, and the sum of the heights of the second metal layer 165 and the third metal layer 220 determines the height of the first cavity 1000 between the first substrate 200 and the resonator unit. The first substrate 200 and the resonator unit are bonded and connected by metal-metal bonding of the second metal layer 165 and the third metal layer 220. Structurally, there is a large-area metal bonding layer between the first substrate 200 and the piezoelectric layer 120, and the first substrate 200 can flexibly select a material with good thermal conductivity. And the sum of the heights of the second metal layer 165 and the third metal layer 220 determines the height of the first cavity 1000 between the first substrate 200 and the resonator unit, while enhancing the supporting capacity, forming a cavity structure that improves the electrical performance of the resonator unit.

[0078] in, Figure 2 and Figure 3 The differences in the FBAW chip structures shown are:

[0079] like Figure 3As shown, the first substrate 200 is provided with a first recess 210 , and the first recess 210 is connected to the first cavity 1000 .

[0080] Specifically, when the total thickness of the second metal layer 165 and the third metal layer 220 is relatively thin and the height of the first cavity 1000 is insufficient, the introduction of the first recess 210 can increase the height of the first cavity 1000, thereby improving the electrical performance of the thin film bulk acoustic wave resonator chip structure.

[0081] Figure 4 and Figure 5 as well as Figure 6 and Figure 7 The following is a thin film bulk acoustic wave resonator chip structure embodiment (embodiment 2) corresponding to Figure 1 The difference between the thin film bulk acoustic wave resonator chip structure and the aforementioned thin film bulk acoustic wave resonator chip structure is that:

[0082] like Figure 4 and Figure 5 as well as Figure 6 and Figure 7 As shown, the thin film bulk acoustic wave resonator chip structure also includes a second substrate 300. Optionally, the second substrate 300 includes at least one of Si, glass, ceramic and silicon carbide. Preferably, the second substrate 300 includes ceramic or silicon carbide with excellent heat dissipation performance, which is the same as the optional material of the first substrate 200.

[0083] The sixth metal layer 310 is located between the second substrate 300 and the fifth metal layer 190; the sixth metal layer 310 includes a sixth metal layer first portion 310a, a sixth metal layer second portion 310b and a sixth metal layer third portion 310c; the sixth metal layer first portion 310a is located on the side of the fifth metal layer first portion 190a away from the piezoelectric layer 120; the sixth metal layer second portion 310b is located on the side of the fifth metal layer second portion 190b away from the piezoelectric layer 120; the sixth metal layer third portion 310c is located on the side of the fifth metal layer third portion 190c away from the piezoelectric layer 120.

[0084] A second recess 305 is disposed on a surface of the second substrate 300 opposite to the resonator unit, and a vertical projection area of ​​the second recess 305 on the first substrate 200 covers a vertical projection area of ​​the first cavity 1000 on the first substrate 200 .

[0085] On the basis of the above-mentioned embodiments, in the technical scheme of the embodiments of the present disclosure, the second substrate 300 of the wafer-level packaging cover and the resonator unit are bonded and connected by metal-to-metal bonding of the sixth metal layer 310 and the fifth metal layer 190. Structurally, there is a large-area metal bonding layer between the second substrate 300 and the piezoelectric layer 120, and the second substrate 300 can flexibly select a material with good thermal conductivity. And the sum of the heights of the sixth metal layer 310 and the fifth metal layer 19 determines the height of the second cavity 2000 between the second substrate 300 and the resonator unit, while enhancing the supporting capacity, forming a cavity structure that improves the electrical performance of the resonator unit. And the setting of the second recess 305 makes a part of the second cavity 2000 between the second substrate 300 and the resonator unit, increases the height of the second cavity 2000, and improves the electrical performance of the thin film bulk acoustic wave resonator chip structure.

[0086] in, Figure 4 and Figure 5 and Figure 6 and Figure 7 The differences in the FBAW chip structures shown are:

[0087] Figure 4 and Figure 5 In the embodiment, the first substrate 200 is provided with a second through hole 230, and the bottom of the second through hole 230 exposes the first portion 220a of the third metal layer and the second portion 220b of the third metal layer. The second through hole 230 serves as a window for external electrical connection of the resonator unit. Figure 6 and Figure 7 In the embodiment, the second substrate 300 is provided with a third through hole 320, and the bottom of the third through hole 320 exposes the first portion 310a of the sixth metal layer and the second portion 310b of the sixth metal layer. The third through hole 320 serves as a window for external electrical connection of the resonator unit.

[0088] in, Figure 5 and Figure 4 The difference is that Figure 5 In the embodiment, the first substrate 200 is provided with a first recess 210 , and the first recess 210 is communicated with the first cavity 1000 . Figure 7 and Figure 6 The difference is that Figure 7 In the embodiment, the first substrate 200 is provided with a first recess 210 , and the first recess 210 is communicated with the first cavity 1000 .

[0089] Specifically, when the total thickness of the second metal layer 165 and the third metal layer 220 is relatively thin and the height of the first cavity 1000 is insufficient, the introduction of the first recess 210 can increase the height of the first cavity 1000, thereby improving the electrical performance of the thin film bulk acoustic wave resonator chip structure.

[0090] Figure 8 The process steps related to the disclosed embodiment of a method for manufacturing a film bulk acoustic wave resonator chip structure are shown, which is called embodiment 3, corresponding to the aforementioned embodiment 1 of the method for manufacturing a film bulk acoustic wave resonator chip structure, including:

[0091] S11: Obtain a temporary substrate.

[0092] S12: forming a buffer layer on one side of the temporary substrate.

[0093] S13: forming a piezoelectric layer, a first metal layer and a first passivation layer in sequence on a side of the buffer layer away from the temporary substrate; the piezoelectric layer comprises an upper surface and a lower surface arranged opposite to each other; the first metal layer is located on the lower surface of the piezoelectric layer; and the first passivation layer is located on a side of the first metal layer away from the piezoelectric layer.

[0094] S14: An isolation groove is formed in the first passivation layer and the first metal layer, the piezoelectric layer is exposed at the bottom of the isolation groove, and the first metal layer is divided into a first metal layer first electrode portion, a first metal layer second electrode connecting portion and a first metal layer resonator peripheral portion by the isolation groove, and the first metal layer resonator peripheral portion encloses and surrounds the first metal layer first electrode portion and the first metal layer second electrode connecting portion.

[0095] S15: A contact hole is formed in the first passivation layer, the contact hole comprising a first contact hole portion, a second contact hole portion and a third contact hole portion, the bottom of the first contact hole portion exposes the first electrode portion of the first metal layer, the bottom of the second contact hole portion exposes the second electrode connecting portion of the first metal layer, and the bottom of the third contact hole portion exposes the peripheral portion of the resonator of the first metal layer.

[0096] S16: A second metal layer is formed on a side of the first passivation layer away from the first metal layer, the second metal layer comprising a second metal layer first portion, a second metal layer second portion, and a second metal layer third portion; the second metal layer first portion is connected to the first electrode portion of the first metal layer through the first contact hole portion; the second metal layer second portion is connected to the second electrode connecting portion of the first metal layer through the second contact hole portion; the second metal layer third portion is connected to the peripheral portion of the resonator of the first metal layer through the third contact hole portion.

[0097] S17: obtaining a first substrate, wherein a third metal layer is formed on one side of the first substrate, and the third metal layer includes a third metal layer first portion, a third metal layer second portion, and a third metal layer third portion.

[0098] S18: Connect the third metal layer and the second metal layer through a bonding process; wherein the first portion of the third metal layer is located on a side of the first portion of the second metal layer away from the first metal layer; the second portion of the third metal layer is located on a side of the second portion of the second metal layer away from the first metal layer; the third portion of the third metal layer is located on a side of the third portion of the second metal layer away from the first metal layer.

[0099] S19: removing the temporary substrate.

[0100] S20: removing the buffer layer.

[0101] S21: forming a fourth metal layer on the upper surface of the piezoelectric layer.

[0102] The piezoelectric layer, the first metal layer and the fourth metal layer constitute a resonator unit, and the sum of the heights of the second metal layer and the third metal layer determines the height of the first cavity between the first substrate and the resonator unit.

[0103] S22: forming a second passivation layer on a side of the fourth metal layer away from the piezoelectric layer.

[0104] S23: patterning the second passivation layer and the fourth metal layer, wherein the second passivation layer covers a portion of the surface of the fourth metal layer.

[0105] S24: A first through hole is formed in the piezoelectric layer, wherein the first through hole includes a first through hole first portion, a first through hole second portion and a first through hole third portion; the bottom of the first through hole first portion exposes the first electrode portion of the first metal layer, the bottom of the first through hole second portion exposes the first metal layer second electrode connecting portion, and the bottom of the first through hole third portion exposes the first metal layer resonator peripheral portion.

[0106] S25: A fifth metal layer is formed on the upper surface of the piezoelectric layer, the fifth metal layer comprising a first portion of the fifth metal layer, a second portion of the fifth metal layer and a third portion of the fifth metal layer; a first end of the first portion of the fifth metal layer is connected to the first electrode portion of the first metal layer through the first portion of the first through hole, and a second end of the first portion of the fifth metal layer is located on the upper surface of the piezoelectric layer; a first end of the second portion of the fifth metal layer is connected to the second electrode connecting portion of the first metal layer through the second portion of the first through hole, and a second end of the second portion of the fifth metal layer is connected to the fourth metal layer; a first end of the third portion of the fifth metal layer is adjacent to the peripheral portion of the resonator of the first metal layer through the third portion of the first through hole, and a second end of the third portion of the fifth metal layer is located on the upper surface of the piezoelectric layer.

[0107] Figure 9-Figure 25 The figure shows a schematic cross-sectional view of each process step related to the manufacturing method of the thin film bulk acoustic wave resonator chip structure (Example 3) of the present disclosure. The following is a detailed description of each related process step in conjunction with the accompanying drawings.

[0108] Fig. 9 It is a detailed process schematic diagram of the process steps related to process steps S11-S12 of the manufacturing method of the thin film bulk acoustic wave resonator chip structure (Example 3) of the present disclosure. A temporary substrate 100 is obtained, and a buffer layer 110 is deposited on the temporary substrate 100. The material of the temporary substrate 100 is silicon, and the material of the buffer layer 110 can optionally include at least one of SiO2, AlN and GaN.

[0109] Figure 10-11 FIG. 1 is a detailed process diagram of process steps related to process step S13 of the method for manufacturing a thin film bulk acoustic wave resonator chip structure (Example 3) disclosed in the present invention. Fig.10 As shown, a piezoelectric layer 120 is deposited on the buffer layer 110, and its material may include aluminum nitride (AlN) or scandium-doped aluminum nitride (ScAlN). Fig.11 As shown, the piezoelectric layer 120 includes an upper surface and a lower surface that are arranged opposite to each other. A first metal layer 130 and a first passivation layer 140 are sequentially deposited on the lower surface of the piezoelectric layer 120. Optionally, the material of the first metal layer 130 includes at least one of Mo, TiW, W, and Ru; optionally, the first passivation layer 140 includes at least one of AlN, SiC, SiO2, and SiN.

[0110] Fig.12 It is a detailed process schematic diagram of the process steps related to process step S14 of the manufacturing method of the thin film bulk acoustic wave resonator chip structure disclosed in the present invention (Example 3). The first passivation layer 140 and the first metal layer 130 are continuously etched and stay on the surface of the piezoelectric layer 120 to form an isolation groove 150. The isolation groove 150 divides the first metal layer 130 into three parts: the first metal layer first electrode part 130a, the first metal layer second electrode connecting part 130b and the first metal layer resonator peripheral part 130c.

[0111] The first metal layer first electrode portion 130a serves as the lower electrode of the resonator unit; the first metal layer second electrode connecting portion 130b is connected to the fifth metal layer second portion 190b via the first through hole second portion 185b, and further connected to the fourth metal layer 170, and the fourth metal layer 170 serves as the upper electrode of the resonator unit; the first metal layer resonator peripheral portion 130c encloses and surrounds the resonator periphery, specifically, the first metal layer first electrode portion 130a and the first metal layer second electrode connecting portion 130b.

[0112] Fig.13 It is a detailed process schematic diagram of the process steps related to process step S15 of the manufacturing method of the thin film bulk acoustic wave resonator chip structure disclosed in the present invention (Example 3). The first passivation layer 140 is etched and stays on the surface of the first metal layer 130 to form a contact hole 160. The contact hole 160 includes a first contact hole portion 160a, a second contact hole portion 160b and a third contact hole portion 160c. The bottom of the first contact hole portion 160a exposes the first metal layer first electrode portion 130a, the bottom of the second contact hole portion 160b exposes the first metal layer second electrode connecting portion 130b, and the bottom of the third contact hole portion 160c exposes the first metal layer resonator peripheral portion 130c.

[0113] Fig.14It is a detailed process schematic diagram of the process steps related to the process step S16 of the manufacturing method of the thin film bulk acoustic wave resonator chip structure disclosed in the present invention (Example 3). A second metal layer 165 is formed on the surface of the first passivation layer 140 and in the contact hole 160 by a metal lift-off process, and the second metal layer 165 includes a first part 165a of the second metal layer, a second part 165b of the second metal layer, and a third part 165c of the second metal layer; the first part 165a of the second metal layer is connected to the first electrode part 130a of the first metal layer through the first part 160a of the contact hole; the second part 165b of the second metal layer is connected to the second electrode connecting part 130b of the first metal layer through the second part 160b of the contact hole; the third part 165c of the second metal layer is connected to the peripheral part 130c of the first metal layer resonator through the third part 160c of the contact hole. Optionally, the second metal layer 165 includes at least one of Ti, Cr, TiW, Al, Au, Cu, Ag and Pt.

[0114] Fig.15 and Fig.16 FIG. 1 is a detailed process diagram of process steps related to process step S17 of the method for manufacturing a thin film bulk acoustic wave resonator chip structure (Example 3) disclosed in the present invention. Fig.15 As shown, a first substrate 200 is obtained, and a patterned third metal layer 220 is formed on the lower surface thereof, wherein the third metal layer 220 includes a third metal layer first portion 220a, a third metal layer second portion 220b, and a third metal layer third portion 220c. The third metal layer 220 includes at least one of Ti, Cr, TiW, Al, Au, Cu, Ag, and Pt, and the optional materials of the third metal layer 220 and the second metal layer 165 are the same.

[0115] Optionally, S17 obtaining the first substrate includes: obtaining the first substrate provided with a first recess, so that after the third metal layer and the second metal layer are connected by a bonding process, the first recess and the first cavity are connected. Fig.16 As shown, the lower surface of the first substrate 200 is etched to form a first recess 210. Figure 3 As shown, after the third metal layer 220 and the second metal layer 165 are connected by a bonding process, the first recess 210 and the first cavity 1000 are connected.

[0116] Specifically, when the total thickness of the second metal layer 165 and the third metal layer 220 is relatively thin and the height of the first cavity 1000 is insufficient, the introduction of the first recess 210 can increase the height of the first cavity 1000, thereby improving the electrical performance of the thin film bulk acoustic wave resonator chip structure.

[0117] Fig.17 and Fig.18It is a detailed process schematic diagram of the process steps related to process step S18 of the manufacturing method of the thin film bulk acoustic wave resonator chip structure disclosed in the present invention (Example 3). The third metal layer 229 is connected to the second metal layer 165 through a bonding process. The first part 165a of the second metal layer, the second part 165b of the second metal layer, and the third part 165c of the second metal layer are aligned and bonded with the first part 220a of the third metal layer, the second part 220b of the third metal layer, and the third part 220c of the third metal layer, respectively, to form a first cavity 1000 after bonding. Fig.18 and Fig.17 The difference is that Fig.18 In the embodiment, a first recess 210 is formed on the lower surface of the first substrate 200 . The introduction of the first recess 210 can increase the height of the first cavity 1000 , thereby improving the electrical performance of the thin film bulk acoustic wave resonator chip structure.

[0118] Fig.19 Detailed process diagram of process steps related to process step S19 of the method for manufacturing a thin film bulk acoustic wave resonator chip structure (Example 3) of the present disclosure. The temporary substrate 100 is removed by grinding and etching processes to expose the surface of the buffer layer 110 .

[0119] Fig. 20 Detailed process diagram of process steps related to process step S20 of the method for manufacturing a thin film bulk acoustic wave resonator chip structure (Example 3) of the present disclosure: The buffer layer 110 is removed by etching to expose the surface of the piezoelectric layer 120 .

[0120] Optionally, before forming the fourth metal layer on the side of the piezoelectric layer away from the first metal layer, S21 further includes: thinning the upper surface of the piezoelectric layer. Fig.21 As shown, a portion of the thickness of the surface of the piezoelectric layer 120 is removed by plasma etching and ion beam etching (IBE) processes, so that the remaining thickness of the piezoelectric layer 120 reaches the target thickness set by the design. The advantage of this is that a piezoelectric layer 120 with good thickness and thickness uniformity is obtained, which is conducive to obtaining a resonator unit with good frequency consistency. At the same time, the piezoelectric layer with relatively poor epitaxial quality of the initial deposition can be removed, and the piezoelectric layer with good epitaxial quality can be retained, thereby obtaining a resonator with better performance.

[0121] Fig. 22It is a detailed process schematic diagram of the process steps related to the process step S21 of the manufacturing method of the thin film bulk acoustic wave resonator chip structure disclosed in the present invention (Example 3). A fourth metal layer 170 and a second passivation layer 180 are sequentially deposited on the upper surface of the piezoelectric layer 120, and the fourth metal layer 170 serves as the upper electrode of the resonator unit. The fourth metal layer 170 includes at least one of Mo, TiW, W, and Ru. The optional materials of the fourth metal layer 170 and the first metal layer 130 are the same. The second passivation layer 180 includes at least one of AlN, SiC, SiO2 and SiN. The optional materials of the second passivation layer 180 and the first passivation layer 140 are the same.

[0122] Optionally, after forming a fourth metal layer on the upper surface of the piezoelectric layer, S21 further includes:

[0123] S22: forming a second passivation layer on a side of the fourth metal layer away from the piezoelectric layer.

[0124] S23: patterning the second passivation layer and the fourth metal layer, wherein the second passivation layer covers a portion of the surface of the fourth metal layer.

[0125] Fig.23 and Fig.24 FIG. 1 is a detailed process diagram of process steps related to process step S23 of the method for manufacturing a thin film bulk acoustic wave resonator chip structure (Example 3) disclosed in the present invention. Fig.23 As shown, the second passivation layer 180 and the fourth metal layer 170 are continuously etched and stay on the surface of the piezoelectric layer 120. Fig.24 As shown, the second passivation layer 180 is etched and stays on the surface of the fourth metal layer 170, the second passivation layer 180 covers part of the surface of the fourth metal layer 170 to expose part of the surface of the fourth metal layer 170, and the part of the fourth metal layer 170 not covered by the second passivation layer 180 serves as the contact connection part between the fifth metal layer 190 and the fourth metal layer 170. Optionally, the second passivation layer 180 includes at least one of AlN, SiC, SiO2 and SiN, which is the same as the optional material of the first passivation layer 140.

[0126] Optionally, after patterning the second passivation layer and the fourth metal layer, S23 includes:

[0127] S24: A first through hole is formed in the piezoelectric layer, wherein the first through hole includes a first through hole first portion, a first through hole second portion and a first through hole third portion; the bottom of the first through hole first portion exposes the first electrode portion of the first metal layer, the bottom of the first through hole second portion exposes the first metal layer second electrode connecting portion, and the bottom of the first through hole third portion exposes the first metal layer resonator peripheral portion.

[0128] S25: A fifth metal layer is formed on the upper surface of the piezoelectric layer, the fifth metal layer comprising a first portion of the fifth metal layer, a second portion of the fifth metal layer and a third portion of the fifth metal layer; a first end of the first portion of the fifth metal layer is connected to the first electrode portion of the first metal layer through the first portion of the first through hole, and a second end of the first portion of the fifth metal layer is located on the upper surface of the piezoelectric layer; a first end of the second portion of the fifth metal layer is connected to the second electrode connecting portion of the first metal layer through the second portion of the first through hole, and a second end of the second portion of the fifth metal layer is connected to the fourth metal layer; a first end of the third portion of the fifth metal layer is adjacent to the peripheral portion of the resonator of the first metal layer through the third portion of the first through hole, and a second end of the third portion of the fifth metal layer is located on the upper surface of the piezoelectric layer.

[0129] Fig.25 FIG. 1 is a detailed process diagram of process steps related to process step S24 of the method for manufacturing a thin film bulk acoustic wave resonator chip structure (Example 3) disclosed in the present invention. Fig.25 As shown, the piezoelectric layer 120 is etched to form a first through hole 185, including a first through hole first portion 185a, a first through hole second portion 185b and a first through hole third portion 185c. The bottom of the first through hole first portion 185a exposes the first metal layer first electrode portion 130a, the bottom of the first through hole second portion 185b exposes the first metal layer second electrode connecting portion 130b, and the bottom of the first through hole third portion 185c exposes the first metal layer resonator peripheral portion 130c.

[0130] like Figure 2 and Figure 3 As shown, the fifth metal layer 190 is formed by a lift-off process, including a first part 190a of the fifth metal layer, a second part 190b of the fifth metal layer and a third part 190c of the fifth metal layer. One end of the first part 190a of the fifth metal layer is connected to the first electrode part 130a of the first metal layer through the first through-hole first part 185a, and the other end is located above the piezoelectric layer 120; one end of the second part 190b of the fifth metal layer is connected to the second electrode connecting part 130b of the first metal layer through the first through-hole second part 185b, and the other end is connected to the fourth metal layer 170; one end of the third part 190c of the fifth metal layer is connected to the resonator peripheral part 130c of the first metal layer through the first through-hole third part 185c, and the other end is located above the piezoelectric layer 120. The fifth metal layer 190 includes at least one of Ti, Cr, TiW, Al, Au, Cu, Ag and Pt, and the optional materials of the fifth metal layer 190 and the second metal layer 165 are the same.

[0131] In the technical solution of the embodiment of the present disclosure, the piezoelectric layer 120, the first metal layer 130 and the fourth metal layer 170 constitute a resonator unit, and the sum of the heights of the second metal layer 165 and the third metal layer 220 determines the height of the first cavity 1000 between the first substrate 200 and the resonator unit. The first substrate 200 and the resonator unit are bonded and connected by metal-metal bonding of the second metal layer 165 and the third metal layer 220. The piezoelectric layer 120 is transferred by metal-metal bonding. In terms of structure, there is a large-area metal bonding layer between the first substrate 200 and the piezoelectric layer 120, and the first substrate 200 can flexibly select a material with good thermal conductivity. And the sum of the heights of the second metal layer 165 and the third metal layer 220 determines the height of the first cavity 1000 between the first substrate 200 and the resonator unit, and while enhancing the supporting capacity, a cavity structure that improves the electrical performance of the resonator unit is formed.

[0132] Fig.26 The figure shows the process steps related to the disclosed embodiment of a method for manufacturing a film bulk acoustic wave resonator chip structure, which is called embodiment 4 and corresponds to the aforementioned embodiment 2 of the method for manufacturing a film bulk acoustic wave resonator chip structure.

[0133] The manufacturing method of the film bulk acoustic wave resonator chip structure comprises:

[0134] S31: Obtain a temporary substrate.

[0135] S32: forming a buffer layer on one side of the temporary substrate.

[0136] S33: A piezoelectric layer, a first metal layer and a first passivation layer are sequentially formed on a side of the buffer layer away from the temporary substrate; the piezoelectric layer includes an upper surface and a lower surface arranged opposite to each other; the first metal layer is located on the lower surface of the piezoelectric layer; and the first passivation layer is located on a side of the first metal layer away from the piezoelectric layer.

[0137] S34: An isolation groove is formed in the first passivation layer and the first metal layer, the bottom of the isolation groove exposes the piezoelectric layer, and the first metal layer is divided into a first metal layer first electrode portion, a first metal layer second electrode connecting portion and a first metal layer resonator peripheral portion by the isolation groove, and the first metal layer resonator peripheral portion encloses and surrounds the first metal layer first electrode portion and the first metal layer second electrode connecting portion.

[0138] S35: A contact hole is formed in the first passivation layer, the contact hole comprising a first contact hole portion, a second contact hole portion and a third contact hole portion, the bottom of the first contact hole portion exposes the first electrode portion of the first metal layer, the bottom of the second contact hole portion exposes the second electrode connecting portion of the first metal layer, and the bottom of the third contact hole portion exposes the peripheral portion of the resonator of the first metal layer.

[0139] S36: A second metal layer is formed on a side of the first passivation layer away from the first metal layer, the second metal layer comprising a second metal layer first portion, a second metal layer second portion and a second metal layer third portion; the second metal layer first portion is connected to the first electrode portion of the first metal layer through the first contact hole; the second metal layer second portion is connected to the second electrode connecting portion of the first metal layer through the second contact hole; the second metal layer third portion is connected to the peripheral portion of the resonator of the first metal layer through the third contact hole.

[0140] S37: Obtain a first substrate, a third metal layer is formed on one side of the first substrate, and the third metal layer includes a third metal layer first portion, a third metal layer second portion and a third metal layer third portion.

[0141] S38: Connect the third metal layer and the second metal layer through a bonding process; wherein the first portion of the third metal layer is located on a side of the first portion of the second metal layer away from the first metal layer; the second portion of the third metal layer is located on a side of the second portion of the second metal layer away from the first metal layer; the third portion of the third metal layer is located on a side of the third portion of the second metal layer away from the first metal layer.

[0142] S39: Remove the temporary substrate.

[0143] S40: removing the buffer layer.

[0144] S41: forming a fourth metal layer on the upper surface of the piezoelectric layer.

[0145] S42: forming a second passivation layer on a side of the fourth metal layer away from the piezoelectric layer.

[0146] S43: patterning the second passivation layer and the fourth metal layer, wherein the second passivation layer covers a portion of the surface of the fourth metal layer.

[0147] S44: A first through hole is formed in the piezoelectric layer, wherein the first through hole includes a first through hole first portion, a first through hole second portion and a first through hole third portion; the bottom of the first through hole first portion exposes the first electrode portion of the first metal layer, the bottom of the first through hole second portion exposes the first metal layer second electrode connecting portion, and the bottom of the first through hole third portion exposes the first metal layer resonator peripheral portion.

[0148] S45: A fifth metal layer is formed on the upper surface of the piezoelectric layer, the fifth metal layer comprising a first portion of a fifth metal layer, a second portion of a fifth metal layer and a third portion of a fifth metal layer; a first end of the first portion of the fifth metal layer is connected to the first electrode portion of the first metal layer through the first portion of the first through hole, and a second end of the first portion of the fifth metal layer is located on the upper surface of the piezoelectric layer; a first end of the second portion of the fifth metal layer is connected to the second electrode connecting portion of the first metal layer through the second portion of the first through hole, and a second end of the second portion of the fifth metal layer is connected to the fourth metal layer; a first end of the third portion of the fifth metal layer is adjacent to the peripheral portion of the resonator of the first metal layer through the third portion of the first through hole, and a second end of the third portion of the fifth metal layer is located on the upper surface of the piezoelectric layer.

[0149] S46: Obtain a second substrate, wherein a second recess is provided on one side of the second substrate.

[0150] S47: forming a sixth metal layer on one side of the second substrate, the sixth metal layer comprising a sixth metal layer first portion, a sixth metal layer second portion and a sixth metal layer third portion.

[0151] S48: Connect the sixth metal layer and the fifth metal layer through a bonding process, wherein the first portion of the sixth metal layer is located on a side of the first portion of the fifth metal layer away from the piezoelectric layer; the second portion of the sixth metal layer is located on a side of the second portion of the fifth metal layer away from the piezoelectric layer; the third portion of the sixth metal layer is located on a side of the third portion of the fifth metal layer away from the piezoelectric layer; the vertical projection area of ​​the second recess on the first substrate covers the vertical projection area of ​​the first cavity on the first substrate, and the second recess is located on the surface opposite to the second substrate and the resonator unit.

[0152] Fig.26 It is shown that the difference between the fourth embodiment and the third embodiment is that after forming the fifth metal layer on the upper surface of the piezoelectric layer in S45 , steps S46 to S48 are also included.

[0153] Figure 27-Figure 28 The figure shows a schematic cross-sectional view of each process step related to the method for manufacturing the thin film bulk acoustic wave resonator chip structure (Example 4) of the present disclosure. The following is a detailed description of each related process step in conjunction with the accompanying drawings.

[0154] like Fig. 27 As shown, a second substrate 300 is obtained, and its lower surface is etched to form a second recess 305 .

[0155] like Fig.28 As shown, a patterned sixth metal layer 310 is formed on the lower surface of the second substrate 300 , including a sixth metal layer first portion 310 a , a sixth metal layer second portion 310 b , and a sixth metal layer third portion 310 c .

[0156] like Figure 4 and Figure 5 as well as Figure 6 and Figure 7 As shown, the first part 190a of the fifth metal layer, the second part 190b of the fifth metal layer, and the third part 190c of the fifth metal layer are aligned and bonded with the first part 310a of the sixth metal layer, the second part 310b of the sixth metal layer, and the third part 310c of the sixth metal layer, respectively, to form a second cavity 2000 after bonding. A second recess 305 is provided on the surface opposite to the resonator unit of the second substrate 300, and the vertical projection area of ​​the second recess 305 on the first substrate 200 covers the vertical projection area of ​​the first cavity 1000 on the first substrate 200. Among them, the first part 310a of the sixth metal layer is located on the side of the first part 190a of the fifth metal layer away from the piezoelectric layer 120; the second part 310b of the sixth metal layer is located on the side of the second part 190b of the fifth metal layer away from the piezoelectric layer 120; and the third part 310c of the sixth metal layer is located on the side of the third part 190c of the fifth metal layer away from the piezoelectric layer 120.

[0157] In the technical solution of the embodiment of the present disclosure, the second substrate 300 of the wafer-level packaging cover and the resonator unit are bonded and connected by metal-to-metal bonding of the sixth metal layer 310 and the fifth metal layer 190. Structurally, there is a large-area metal bonding layer between the second substrate 300 and the piezoelectric layer 120, and the second substrate 300 can flexibly select a material with good thermal conductivity. And the sum of the heights of the sixth metal layer 310 and the fifth metal layer 19 determines the height of the second cavity 2000 between the second substrate 300 and the resonator unit, while enhancing the supporting capacity, forming a cavity structure that improves the electrical performance of the resonator unit. And the setting of the second recess 305 makes a part of the second cavity 2000 between the second substrate 300 and the resonator unit, increases the height of the second cavity 2000, and improves the electrical performance of the thin film bulk acoustic wave resonator chip structure.

[0158] in, Figure 4 and Figure 5 and Figure 6 and Figure 7 The differences in the FBAW chip structures shown are:

[0159] Figure 4 and Figure 5 In the embodiment, the first substrate 200 is provided with a second through hole 230, and the bottom of the second through hole 230 exposes the first portion 220a of the third metal layer and the second portion 220b of the third metal layer. The second through hole 230 serves as a window for external electrical connection of the resonator unit. Figure 6 and Figure 7 In the embodiment, the second substrate 300 is provided with a third through hole 320, and the bottom of the third through hole 320 exposes the first portion 310a of the sixth metal layer and the second portion 310b of the sixth metal layer. The third through hole 320 serves as a window for external electrical connection of the resonator unit.

[0160] in, Figure 5 and Figure 4 The difference is that Figure 5 In the embodiment, the first substrate 200 is provided with a first recess 210 , and the first recess 210 is communicated with the first cavity 1000 . Figure 7 and Figure 6 The difference is that Figure 7 In the embodiment, the first substrate 200 is provided with a first recess 210 , and the first recess 210 is communicated with the first cavity 1000 .

[0161] Specifically, when the total thickness of the second metal layer 165 and the third metal layer 220 is relatively thin and the height of the first cavity 1000 is insufficient, the introduction of the first recess 210 can increase the height of the first cavity 1000, thereby improving the electrical performance of the thin film bulk acoustic wave resonator chip structure.

[0162] It must be noted that the above are only specific implementation methods of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, which should be covered by the protection scope of the present disclosure.

Claims

1. A thin film bulk acoustic wave resonator chip structure, characterized in that: include: a first substrate; A piezoelectric layer is located on one side of the first substrate; the piezoelectric layer includes an upper surface and a lower surface that are oppositely arranged; The lower surface of the piezoelectric layer is a surface facing the first substrate; A first metal layer is located on the lower surface of the piezoelectric layer, the first metal layer is provided with an isolation groove, the bottom of the isolation groove exposes the piezoelectric layer, the first metal layer is divided into a first metal layer first electrode portion, a first metal layer second electrode connecting portion and a first metal layer resonator peripheral portion by the isolation groove, and the first metal layer resonator peripheral portion encloses and surrounds the first metal layer first electrode portion and the first metal layer second electrode connecting portion; A first passivation layer, located on a side of the first metal layer away from the piezoelectric layer; The isolation groove also penetrates the first passivation layer; The first passivation layer is provided with a contact hole, the contact hole comprises a first contact hole portion, a second contact hole portion and a third contact hole portion, the bottom of the first contact hole portion exposes the first electrode portion of the first metal layer, the bottom of the second contact hole portion exposes the second electrode connecting portion of the first metal layer, and the bottom of the third contact hole portion exposes the resonator peripheral portion of the first metal layer; The second metal layer is located on a side of the first passivation layer away from the first metal layer, and includes a first portion of the second metal layer, a second portion of the second metal layer, and a third portion of the second metal layer; the first portion of the second metal layer is connected to the first electrode portion of the first metal layer through the first portion of the contact hole; the second portion of the second metal layer is connected to the second electrode connecting portion of the first metal layer through the second portion of the contact hole; and the third portion of the second metal layer is connected to the resonator peripheral portion of the first metal layer through the third portion of the contact hole; a third metal layer, located on one side of the first substrate, comprising a first portion of the third metal layer, a second portion of the third metal layer and a third portion of the third metal layer; the first portion of the third metal layer is located on a side of the first portion of the second metal layer away from the first metal layer; the second portion of the third metal layer is located on a side of the second portion of the second metal layer away from the first metal layer; the third portion of the third metal layer is located on a side of the third portion of the second metal layer away from the first metal layer; a fourth metal layer, located on the upper surface of the piezoelectric layer; The piezoelectric layer, the first metal layer and the fourth metal layer constitute a resonator unit, and the sum of the heights of the second metal layer and the third metal layer determines the height of a first cavity between the first substrate and the resonator unit.

2. The thin film bulk acoustic wave resonator chip structure according to claim 1, characterized in that: It also includes a second passivation layer located on a side of the fourth metal layer away from the piezoelectric layer, and the second passivation layer covers a portion of the surface of the fourth metal layer.

3. The thin film bulk acoustic wave resonator chip structure according to claim 2, characterized in that: The piezoelectric layer is provided with a first through hole, including a first through hole first portion, a first through hole second portion and a first through hole third portion; the bottom of the first through hole first portion exposes the first metal layer first electrode portion, the bottom of the first through hole second portion exposes the first metal layer second electrode connecting portion, and the bottom of the first through hole third portion exposes the first metal layer resonator peripheral portion; The thin film bulk acoustic wave resonator chip structure further includes a fifth metal layer, which is located on the upper surface of the piezoelectric layer and includes a first portion of the fifth metal layer, a second portion of the fifth metal layer and a third portion of the fifth metal layer; The first end of the first part of the fifth metal layer is connected to the first electrode part of the first metal layer through the first part of the first through hole, and the second end of the first part of the fifth metal layer is located on the upper surface of the piezoelectric layer; the first end of the second part of the fifth metal layer is connected to the second electrode connecting part of the first metal layer through the second part of the first through hole, and the second end of the second part of the fifth metal layer is connected to the fourth metal layer; the first end of the third part of the fifth metal layer is adjacent to the peripheral part of the resonator of the first metal layer through the third part of the first through hole, and the second end of the third part of the fifth metal layer is located on the upper surface of the piezoelectric layer.

4. The thin film bulk acoustic wave resonator chip structure according to any one of claims 1 to 3, characterized in that: The first substrate is provided with a first recess, and the first recess is communicated with the first cavity.

5. The thin film bulk acoustic wave resonator chip structure according to claim 3, characterized in that: Also comprising a second substrate; a sixth metal layer, located between the second substrate and the fifth metal layer; the sixth metal layer comprises a first portion of the sixth metal layer, a second portion of the sixth metal layer and a third portion of the sixth metal layer; the first portion of the sixth metal layer is located on a side of the first portion of the fifth metal layer away from the piezoelectric layer; the second portion of the sixth metal layer is located on a side of the second portion of the fifth metal layer away from the piezoelectric layer; the third portion of the sixth metal layer is located on a side of the third portion of the fifth metal layer away from the piezoelectric layer; A second recess is disposed on a surface of the second substrate opposite to the resonator unit, and a vertical projection area of ​​the second recess on the first substrate covers a vertical projection area of ​​the first cavity on the first substrate.

6. The thin film bulk acoustic wave resonator chip structure according to claim 5, characterized in that: The first substrate is provided with a second through hole, and the bottom of the second through hole exposes the first portion of the third metal layer and the second portion of the third metal layer.

7. The thin film bulk acoustic wave resonator chip structure according to claim 5, characterized in that: The second substrate is provided with a third through hole, and the bottom of the third through hole exposes the first portion of the sixth metal layer and the second portion of the sixth metal layer.

8. The thin film bulk acoustic wave resonator chip structure according to any one of claims 5 to 7, characterized in that: The first substrate is provided with a first recess, and the first recess is communicated with the first cavity.

9. The thin film bulk acoustic wave resonator chip structure according to claim 1, characterized in that: The first substrate includes any one of Si, glass, ceramic and silicon carbide.

10. The thin film bulk acoustic wave resonator chip structure according to claim 5, characterized in that: The second substrate includes any one of Si, glass, ceramic and silicon carbide.

11. A method for manufacturing a thin film bulk acoustic wave resonator chip structure, characterized in that: include: obtaining a temporary substrate; forming a buffer layer on one side of the temporary substrate; A piezoelectric layer, a first metal layer and a first passivation layer are sequentially formed on a side of the buffer layer away from the temporary substrate; the piezoelectric layer comprises an upper surface and a lower surface arranged opposite to each other; the first metal layer is located on the lower surface of the piezoelectric layer; and the first passivation layer is located on a side of the first metal layer away from the piezoelectric layer; An isolation groove is formed in the first passivation layer and the first metal layer, the bottom of the isolation groove exposes the piezoelectric layer, the first metal layer is divided into a first metal layer first electrode portion, a first metal layer second electrode connecting portion and a first metal layer resonator peripheral portion by the isolation groove, and the first metal layer resonator peripheral portion closes and surrounds the first metal layer first electrode portion and the first metal layer second electrode connecting portion; A contact hole is formed in the first passivation layer, the contact hole comprising a first contact hole portion, a second contact hole portion and a third contact hole portion, the bottom of the first contact hole portion exposes the first electrode portion of the first metal layer, the bottom of the second contact hole portion exposes the second electrode connecting portion of the first metal layer, and the bottom of the third contact hole portion exposes the resonator peripheral portion of the first metal layer; A second metal layer is formed on a side of the first passivation layer away from the first metal layer, the second metal layer comprising a first portion of the second metal layer, a second portion of the second metal layer, and a third portion of the second metal layer; the first portion of the second metal layer is connected to the first electrode portion of the first metal layer through the first portion of the contact hole; the second portion of the second metal layer is connected to the second electrode connecting portion of the first metal layer through the second portion of the contact hole; the third portion of the second metal layer is connected to the resonator peripheral portion of the first metal layer through the third portion of the contact hole; Obtaining a first substrate, wherein a third metal layer is formed on one side of the first substrate, and the third metal layer includes a third metal layer first portion, a third metal layer second portion, and a third metal layer third portion; The third metal layer and the second metal layer are connected by a bonding process; wherein the first portion of the third metal layer is located on a side of the first portion of the second metal layer away from the first metal layer; the second portion of the third metal layer is located on a side of the second portion of the second metal layer away from the first metal layer; the third portion of the third metal layer is located on a side of the third portion of the second metal layer away from the first metal layer; removing the temporary substrate; removing the buffer layer; forming a fourth metal layer on the upper surface of the piezoelectric layer; The piezoelectric layer, the first metal layer and the fourth metal layer constitute a resonator unit, and the sum of the heights of the second metal layer and the third metal layer determines the height of a first cavity between the first substrate and the resonator unit.

12. The method for manufacturing a thin film bulk acoustic wave resonator chip structure according to claim 11, characterized in that: After forming a fourth metal layer on the upper surface of the piezoelectric layer, the method further comprises: forming a second passivation layer on a side of the fourth metal layer away from the piezoelectric layer; The second passivation layer and the fourth metal layer are patterned, wherein the second passivation layer covers a portion of the surface of the fourth metal layer.

13. The method for manufacturing a thin film bulk acoustic wave resonator chip structure according to claim 12, characterized in that: After patterning the second passivation layer and the fourth metal layer, the method comprises: A first through hole is formed in the piezoelectric layer, wherein the first through hole includes a first through hole first portion, a first through hole second portion and a first through hole third portion; the bottom of the first through hole first portion exposes the first metal layer first electrode portion, the bottom of the first through hole second portion exposes the first metal layer second electrode connecting portion, and the bottom of the first through hole third portion exposes the first metal layer resonator peripheral portion; A fifth metal layer is formed on the upper surface of the piezoelectric layer, the fifth metal layer comprising a first portion of a fifth metal layer, a second portion of a fifth metal layer and a third portion of a fifth metal layer; a first end of the first portion of the fifth metal layer is connected to the first electrode portion of the first metal layer through the first portion of the first through hole, and a second end of the first portion of the fifth metal layer is located on the upper surface of the piezoelectric layer; a first end of the second portion of the fifth metal layer is connected to the second electrode connecting portion of the first metal layer through the second portion of the first through hole, and a second end of the second portion of the fifth metal layer is connected to the fourth metal layer; a first end of the third portion of the fifth metal layer is adjacent to the peripheral portion of the resonator of the first metal layer through the third portion of the first through hole, and a second end of the third portion of the fifth metal layer is located on the upper surface of the piezoelectric layer.

14. The method for manufacturing a thin film bulk acoustic wave resonator chip structure according to any one of claims 11 to 13, characterized in that: Obtaining a first substrate includes: A first substrate provided with a first recess is obtained, so that after the third metal layer and the second metal layer are connected by a bonding process, the first recess and the first cavity are connected.

15. The method for manufacturing a thin film bulk acoustic wave resonator chip structure according to claim 13, characterized in that: After forming a fifth metal layer on the upper surface of the piezoelectric layer, the method further comprises: Obtaining a second substrate, wherein a second recess is provided on one side of the second substrate; forming a sixth metal layer on one side of the second substrate, the sixth metal layer comprising a sixth metal layer first portion, a sixth metal layer second portion and a sixth metal layer third portion; The sixth metal layer and the fifth metal layer are connected by a bonding process, wherein the first portion of the sixth metal layer is located on a side of the first portion of the fifth metal layer away from the piezoelectric layer; the second portion of the sixth metal layer is located on a side of the second portion of the fifth metal layer away from the piezoelectric layer; the third portion of the sixth metal layer is located on a side of the third portion of the fifth metal layer away from the piezoelectric layer; the vertical projection area of ​​the second recess on the first substrate covers the vertical projection area of ​​the first cavity on the first substrate, and the second recess is located on a surface of the second substrate opposite to the resonator unit.

16. The method for manufacturing a thin film bulk acoustic wave resonator chip structure according to claim 15, characterized in that: After connecting the sixth metal layer and the fifth metal layer through a bonding process, the method further includes: A second through hole is formed in the first substrate, and a bottom of the second through hole exposes the first portion of the third metal layer and the second portion of the third metal layer.

17. The method for manufacturing a thin film bulk acoustic wave resonator chip structure according to claim 15, characterized in that: After connecting the sixth metal layer and the fifth metal layer through a bonding process, the method further includes: A third through hole is formed in the second substrate, and a bottom of the third through hole exposes the first portion of the sixth metal layer and the second portion of the sixth metal layer.

18. The method for manufacturing a thin film bulk acoustic wave resonator chip structure according to any one of claims 15 to 17, characterized in that: Obtaining a first substrate includes: A first substrate provided with a first recess is obtained, so that after the third metal layer and the second metal layer are connected by a bonding process, the first recess and the first cavity are connected.

19. The method for manufacturing a thin film bulk acoustic wave resonator chip structure according to claim 11, characterized in that: Before forming a fourth metal layer on a side of the piezoelectric layer away from the first metal layer, the method further includes: The upper surface of the piezoelectric layer is thinned.

20. The method for manufacturing a thin film bulk acoustic wave resonator chip structure according to claim 11, characterized in that: The first substrate includes any one of Si, glass, ceramic and silicon carbide.

21. The method for manufacturing a thin film bulk acoustic wave resonator chip structure according to claim 15, characterized in that: The second substrate includes any one of Si, glass, ceramic and silicon carbide.

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