Preparation method for heterogeneous integrated filter, and heterogeneous integrated filter

Abstract

The present application relates to the technical field of semiconductor devices, and specifically relates to a preparation method for a heterogeneous integrated filter, and a heterogeneous integrated filter. The preparation method comprises: providing a resonator on a surface of a first substrate; providing a passive device on a surface of a second substrate, and providing a bonding structure on the surface of the second substrate facing away from the passive device; bonding the first substrate to the second substrate by means of the bonding structure; and providing a through hole in the second substrate, and providing a metal connection line in the through hole, such that the resonator is electrically connected to the passive device. By means of improvements to a manufacturing process, the present application can improve yield and effectively reduce manufacturing costs.

Description

Fabrication method of heterogeneous integrated filter and heterogeneous integrated filter

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 2025101315327, filed on February 6, 2025, entitled "Method for fabricating heterogeneous integrated filters and heterogeneous integrated filters", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of semiconductor device technology, and more specifically, to a method for fabricating a heterogeneous integrated filter and a heterogeneous integrated filter. Background Technology

[0004] Connecting acoustic resonators in series or parallel with passive components such as capacitors and inductors can shift the series or parallel resonant frequencies of the resonator. Utilizing this characteristic, the effective electromechanical coupling coefficient of the hybrid resonator can be increased by rationally designing the values ​​and connections of the passive components. To integrate acoustic resonators and passive components at the wafer level, a heterogeneous integrated filter with high bandwidth, high suppression, and small size can be obtained. Current technology typically fabricates passive components such as capacitors on the package structure of the acoustic resonator. Since capacitors and other components require relatively flat surfaces to achieve controllable fabrication precision, an inorganic layer is usually deposited on the redistribution layer surface, followed by polishing. This process involves multiple steps, and defects accumulate at different stages, ultimately leading to a decrease in fabrication yield.

[0005] Application content

[0006] The purpose of this application is to provide a method for fabricating a heterogeneous integrated filter and a heterogeneous integrated filter, which can improve the yield and effectively reduce the manufacturing cost by improving the fabrication process.

[0007] The embodiments of this application are implemented as follows:

[0008] In a first aspect, embodiments of this application provide a method for fabricating a heterogeneous integrated filter, comprising:

[0009] A resonator is disposed on the surface of the first substrate;

[0010] A passive device is disposed on the surface of a second substrate, and a bonding structure is disposed on the surface of the second substrate opposite to the passive device; wherein, a metal bump is disposed on the surface of the second substrate, and the metal bump is electrically connected to the passive device;

[0011] The first substrate and the second substrate are bonded together by the bonding structure;

[0012] A through-hole is formed on the second substrate, and a metal connecting wire is provided in the through-hole to electrically connect the resonator to the passive device.

[0013] As an optional implementation, the bonding structure disposed on the second substrate is a non-metallic bonding structure;

[0014] The step of forming a through-hole on the second substrate and providing a metal connection wire within the through-hole to electrically connect the resonator to the passive device includes:

[0015] A first through-hole is formed on the second substrate, and the first through-hole penetrates the non-metallic bonding structure;

[0016] A first metal connection line is formed inside the first through hole, with one end of the first metal connection line connected to the resonator and the other end connected to the passive device.

[0017] As an optional implementation, the bonding structure disposed on the second substrate is a metal bonding structure;

[0018] The step of forming a through-hole on the second substrate and providing a metal connection wire within the through-hole to electrically connect the resonator to the passive device includes:

[0019] A second through-hole is formed on the second substrate;

[0020] A second metal connection line is formed in the second through hole, one end of the second metal connection line is connected to the metal bonding structure and the other end is connected to the passive device.

[0021] As an optional implementation, the step of setting a passive device on the surface of the second substrate and setting a bonding structure on the surface of the second substrate opposite to the passive device includes:

[0022] The surface of the second substrate facing away from the resonator is polished to obtain a polished surface.

[0023] Passive devices are disposed on the polished surface.

[0024] As an optional implementation, the step of setting a passive device on the polished plane includes:

[0025] A bottom metal layer, an insulating layer, and a top metal layer are sequentially stacked on the polished surface.

[0026] As an optional implementation, after forming metal bumps on the surface of the second substrate and electrically connecting the metal bumps to the passive device, the method includes:

[0027] A protective layer is formed on the surface of the second substrate;

[0028] A cutout is formed in the protective layer to expose the metal protrusion.

[0029] As an optional implementation, the first substrate is bonded to the bonding structure, including:

[0030] A cavity is formed between the first substrate and the second substrate.

[0031] As an optional implementation, the resonator is disposed on the surface of the first substrate, comprising:

[0032] A bottom electrode layer, a piezoelectric layer, and an upper electrode layer are sequentially stacked on the surface of the first substrate.

[0033] Secondly, the heterogeneous integrated filter provided in this application embodiment is fabricated using the above-described fabrication method.

[0034] The beneficial effects of the embodiments of this application include:

[0035] This application provides a method for fabricating a heterogeneous integrated filter, comprising: fabricating a resonator on the surface of a first substrate; fabricating a passive device on the surface of a second substrate; and fabricating a bonding structure on the surface of the second substrate opposite to the passive device; bonding the first substrate and the second substrate through the bonding structure; forming a through-hole on the second substrate and placing a metal interconnect within the through-hole to electrically connect the resonator and the passive device. Compared to the prior art, this application uses two independent substrates, fabricating the resonator on the first substrate and the passive device on the second substrate, and then bonding the first substrate and the second substrate. This application can fabricate the resonator and the passive device separately on the first substrate and the second substrate, respectively, allowing the two devices to be fabricated independently. This avoids the need to continuously integrate the process steps of the two devices on a single substrate, effectively improving yield and reducing production costs. Furthermore, the separate fabrication of the two devices also improves production efficiency.

[0036] This application provides a heterogeneous integrated filter, which is fabricated using the above-described method. In the heterogeneous integrated filter provided by this application, a resonator and a passive device are fabricated on a first substrate and a second substrate, respectively. The two devices can be fabricated separately, avoiding the need to continuously integrate the fabrication steps of the two devices onto a single substrate. This effectively improves yield and reduces production costs. Attached Figure Description

[0037] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 is a schematic diagram of one of the heterogeneous integrated filter structures according to an embodiment of this application;

[0039] Figure 2 is a second schematic diagram of the heterogeneous integrated filter structure according to an embodiment of this application;

[0040] Figure 3 is a schematic diagram of the heterogeneous integrated filter structure according to an embodiment of this application;

[0041] Figure 4 is a schematic diagram of the heterogeneous integrated filter structure according to an embodiment of this application.

[0042] icon:

[0043] 100 - First substrate; 101 - Resonator; 102 - Second substrate; 103 - Passive device; 104 - Non-metallic bonding structure; 105 - First through-hole; 106 - First metal connection line; 107 - Metallic bonding structure; 108 - Second through-hole; 109 - Second metal connection line; 110 - Cavity. Embodiments of the present invention

[0044] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0045] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0046] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0047] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0048] Connecting acoustic resonators in series or parallel with passive components such as capacitors and inductors can shift the series or parallel resonant frequencies of the resonator. Utilizing this characteristic, the effective electromechanical coupling coefficient of the hybrid resonator can be increased by rationally designing the values ​​and connections of the passive components. To integrate acoustic resonators and passive components at the wafer level, a heterogeneous integrated filter with high bandwidth, high suppression, and small size can be obtained. Current technology typically fabricates passive components such as capacitors on the package structure of the acoustic resonator. Since capacitors and other components require relatively flat surfaces to achieve controllable fabrication precision, an inorganic layer is usually deposited on the redistribution layer surface, followed by polishing. This process involves multiple steps, and defects accumulate at different stages, ultimately leading to a decrease in fabrication yield.

[0049] To address the aforementioned technical problems, this application provides a method for fabricating a heterogeneous integrated filter and a heterogeneous integrated filter.

[0050] Referring to Figures 1 and 3, this application provides a method for fabricating a heterogeneous integrated filter, including:

[0051] A resonator 101 is disposed on the surface of the first substrate 100;

[0052] A passive device 103 is disposed on the surface of the second substrate 102, and a bonding structure is disposed on the surface of the second substrate 102 opposite to the passive device 103.

[0053] The first substrate 100 and the second substrate 102 are bonded together by a bonding structure;

[0054] A through-hole is formed on the second substrate 102, and a metal connecting wire is provided in the through-hole to electrically connect the resonator 101 to the passive device 103.

[0055] It should be noted that in this embodiment of the application, a resonator 101 is formed on the surface of the first substrate 100, and a passive device 103 is formed on the surface of the second substrate 102. The resonator 101 and the passive device 103 can be manufactured separately, avoiding the need to fabricate the passive device 103 on the already fabricated resonator 101. This prevents the continuous integration of process steps on a single module, avoids the accumulation of defects at multiple different stages, and thus effectively improves production yield.

[0056] The passive device 103 in this application embodiment includes one or a combination of capacitors, inductors and resistors.

[0057] For example, a capacitor is formed on the surface of the second substrate 102. For example, an inductor is formed on the surface of the second substrate 102. For example, a resistor is formed on the surface of the second substrate 102.

[0058] In this embodiment, a bonding structure is provided on the surface of the second substrate 102 opposite to the passive device 103. The bonding structure can be a metallic bonding structure 107 or a non-metallic bonding structure 104. Those skilled in the art can choose according to their needs, and no special limitation is made.

[0059] Compared to existing technologies, this application embodiment uses two independent substrates. A resonator 101 is fabricated on a first substrate 100, and a passive device 103 is fabricated on a second substrate 102. Then, the first substrate 100 and the second substrate 102 are bonded together. This application embodiment can fabricate the resonator 101 and the passive device 103 on the first substrate 100 and the second substrate 102 respectively. The two devices can be fabricated independently, avoiding the need to continuously integrate the process steps of the two devices onto a single substrate, effectively improving yield and reducing production costs. Furthermore, the separate fabrication of the two devices in this application embodiment also improves production efficiency.

[0060] In this embodiment of the application, a resonator 101 is disposed on the surface of the first substrate 100, including:

[0061] A bottom electrode layer, a piezoelectric layer, and an upper electrode layer are sequentially stacked on the surface of the first substrate 100.

[0062] Referring to Figures 1 and 2, as an optional embodiment, the bonding structure disposed on the second substrate 102 is a non-metallic bonding structure 104.

[0063] The process of forming a through-hole on the second substrate 102 and providing a metal interconnect within the through-hole to electrically connect the resonator 101 to the passive device 103 includes:

[0064] A first through hole 105 is formed on the second substrate 102, and the first through hole 105 penetrates the non-metallic bonding structure 104.

[0065] A first metal connection line 106 is formed inside the first through hole 105. One end of the first metal connection line 106 is connected to the resonator 101 and the other end is connected to the passive device 103.

[0066] It should be noted that a non-metallic bonding structure 104 is fabricated on the second substrate 102. This non-metallic bonding structure 104 can connect the first substrate 100 and the second substrate 102, and can also support the first substrate 100 and the second substrate 102. That is to say, the non-metallic bonding structure 104 in this embodiment of the application has a supporting function.

[0067] It should be noted that the bonding surfaces formed by the non-metallic bonding structure 104 connecting to the first substrate 100 and the second substrate 102 can be silicon-silicon bonds or glass-glass bonds. Those skilled in the art can choose the appropriate method as needed, and this application does not impose any special limitations on this.

[0068] During the actual bonding process, the two surfaces to be bonded are cleaned and polished to ensure they are smooth and free of contaminants. The two surfaces are then gently brought into contact and a certain amount of pressure is applied to ensure a tight bond. Finally, annealing at a high temperature is performed to enhance the bond strength. For silicon-silicon bonding, annealing is typically carried out between 400-1200℃. It should be noted that direct bonding does not introduce an additional metal layer or adhesive, reducing parasitic capacitance and resistance.

[0069] Referring to Figures 3 and 4, as an optional embodiment, the bonding structure provided on the second substrate 102 is a metal bonding structure 107;

[0070] The process of forming a through-hole on the second substrate 102 and providing a metal interconnect within the through-hole to electrically connect the resonator 101 to the passive device 103 includes:

[0071] A second through-hole 108 is formed on the second substrate 102;

[0072] A second metal connection line 109 is formed inside the second through hole 108. One end of the second metal connection line 109 is connected to the metal bonding structure 107, and the other end is connected to the passive device 103.

[0073] Unlike the above embodiments, the embodiments of this application employ a metal bonding structure 107.

[0074] As an optional implementation, referring to Figures 3 and 4, the metal bonding structure 107 includes a first part and a second part that are independent of each other, spaced apart and not connected, thereby ensuring insulation between them. A second metal connection line 109 is connected to the first part via a second through-hole 108, and another second metal connection line 109 is connected to the second part via another second through-hole 108. Thus, one electrode of the passive device is electrically connected to one electrode of the resonator 101 via a second metal connection line 109 and the first part, and the other electrode of the passive device is electrically connected to the other electrode of the resonator 101 via another second metal connection line 109 and the second part.

[0075] The metal bonding structure 107 of this application embodiment can connect the first substrate 100 and the second substrate 102, and can also support the first substrate 100 and the second substrate 102. That is to say, the metal bonding structure 107 of this application embodiment has a supporting function.

[0076] It should be noted that, in this embodiment of the application, a cavity 110 is formed between the first substrate 100 and the second substrate 102. The size of the cavity 110 can be controlled by the thickness of the bonding structure. Increasing the thickness of the bonding structure can increase the size of the cavity 110 between the first substrate 100 and the second substrate 102, resulting in a larger gap between the resonator 101 and the passive device 103, thus avoiding parasitic problems between the resonator 101 and the passive device 103. For example, as shown in FIG1 or FIG3, at least part of the cavity is located between the resonator 101 and the second substrate 102.

[0077] As an alternative implementation, the metal bonding structure 107 is located within the cavity 110, so the first and second parts of the metal bonding structure 107 can be isolated by the air inside the cavity 110.

[0078] As an optional implementation, the first substrate 100 and the second substrate 102 are stacked to reduce the area occupied in the horizontal direction. Optionally, the orthographic projection of the passive device 103 on the first substrate 100 should fall within the orthographic projection of the resonator 101 on the first substrate 100.

[0079] As an optional implementation, a passive device 103 is disposed on the surface of the second substrate 102, and a bonding structure is disposed on the surface of the second substrate 102 opposite to the passive device 103, including:

[0080] The surface of the second substrate 102 facing away from the resonator 101 is polished to obtain a polished surface;

[0081] Passive device 103 is placed on the polished surface.

[0082] It should be noted that, in this embodiment of the application, the surface of the second substrate 102 facing away from the resonator 101 is mechanically ground and polished, and the second substrate 102 is thinned.

[0083] It should be noted that the passive device 103 in this application embodiment includes one or a combination of capacitors, resistors and inductors.

[0084] For example, a MIM capacitor is fabricated on a second substrate 102.

[0085] Specifically, setting the passive device 103 on the polished surface includes:

[0086] A bottom metal layer, an insulating layer, and a top metal layer are sequentially stacked on the polished surface.

[0087] As an optional implementation, as shown in FIG3, the insulating layer has an extension that extends from the upper surface of the bottom metal layer through its sidewall to the upper surface of the second substrate 102 (i.e., the side surface away from the resonator 101 or the first substrate 100). The second metal connection line 109 connected to the top metal layer can climb to the upper surface of the insulating layer by means of the extension of the insulating layer, thereby facilitating contact and connection with the top metal layer, while also being insulated from the bottom metal layer by means of the extension of the insulating layer, ensuring reliability.

[0088] As an optional implementation, referring to Figure 3, the second metal connecting line 109 connected to the top metal layer extends from the side of the top metal layer to its upper surface (the side surface facing away from the bottom metal layer), which improves the stability and reliability of the contact connection between the two. Similarly, referring to Figure 3, the bottom metal layer has a relatively extended connecting portion, the upper surface of which does not have an insulating layer or a top metal layer, and the second metal connecting line 109 connected to the bottom metal layer extends from the side of the bottom metal layer to its upper surface (the side surface near the top metal layer), which improves the stability and reliability of the contact connection between the two.

[0089] As an optional implementation, a passive device 103 is disposed on the surface of the second substrate 102, and a bonding structure is disposed on the surface of the second substrate 102 opposite to the passive device 103, including:

[0090] Metal bumps are provided on the surface of the second substrate 102, and the metal bumps are electrically connected to the passive device 103.

[0091] As an optional implementation, after forming metal bumps on the surface of the second substrate 102 and electrically connecting the metal bumps to the passive device 103, the method includes:

[0092] A protective layer is formed on the surface of the second substrate 102;

[0093] Hollowed-out sections are formed in the protective layer to expose the metal protrusions.

[0094] This application provides a heterogeneous integrated filter, which is fabricated using the above-described method. In the heterogeneous integrated filter provided by this application, a resonator 101 and a passive device 103 are fabricated on a first substrate 100 and a second substrate 102, respectively. The two devices can be fabricated separately, avoiding the need to continuously integrate the process steps of the two devices onto a single substrate, effectively improving yield and reducing production costs.

[0095] In addition, the embodiments of this application can also improve production efficiency by fabricating the two devices separately.

[0096] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application. Industrial applicability

[0097] The heterogeneous integrated filter fabrication method and heterogeneous integrated filter of this application can improve yield and effectively reduce manufacturing costs through improvements in the fabrication process.

Claims

1. A method for fabricating a heterogeneous integrated filter, characterized in that, include: A resonator is disposed on the surface of the first substrate; A passive device is disposed on the surface of a second substrate, and a bonding structure is disposed on the surface of the second substrate opposite to the passive device; wherein, a metal bump is disposed on the surface of the second substrate, and the metal bump is electrically connected to the passive device; The first substrate and the second substrate are bonded together by the bonding structure; A through-hole is formed on the second substrate, and a metal connecting wire is provided in the through-hole to electrically connect the resonator to the passive device.

2. The method for fabricating a heterogeneous integrated filter according to claim 1, characterized in that, The bonding structure disposed on the second substrate is a non-metallic bonding structure; The step of forming a through-hole on the second substrate and providing a metal connection wire within the through-hole to electrically connect the resonator to the passive device includes: A first through-hole is formed on the second substrate, and the first through-hole penetrates the non-metallic bonding structure; A first metal connection line is formed inside the first through hole, with one end of the first metal connection line connected to the resonator and the other end connected to the passive device.

3. The method for fabricating a heterogeneous integrated filter according to claim 1, characterized in that, The bonding structure disposed on the second substrate is a metal bonding structure; The step of forming a through-hole on the second substrate and providing a metal connection wire within the through-hole to electrically connect the resonator to the passive device includes: A second through-hole is formed on the second substrate; A second metal connection line is formed in the second through hole, one end of the second metal connection line is connected to the metal bonding structure and the other end is connected to the passive device.

4. The method for fabricating a heterogeneous integrated filter according to any one of claims 1-3, characterized in that, The step of setting a passive device on the surface of the second substrate and setting a bonding structure on the surface of the second substrate opposite to the passive device includes: The surface of the second substrate facing away from the resonator is polished to obtain a polished surface. Passive devices are disposed on the polished surface.

5. The method for fabricating a heterogeneous integrated filter according to claim 4, characterized in that, The polishing process on the side of the second substrate facing away from the resonator to obtain a polished plane includes: The surface of the second substrate facing away from the resonator is mechanically ground, polished, and thinned to obtain the polished plane.

6. The method for fabricating a heterogeneous integrated filter according to claim 4, characterized in that, The step of setting a passive device on the polished surface includes: A bottom metal layer, an insulating layer, and a top metal layer are sequentially stacked on the polished surface.

7. The method for fabricating a heterogeneous integrated filter according to claim 1, characterized in that, After forming a metal bump on the surface of the second substrate and electrically connecting the metal bump to the passive device, the method includes: A protective layer is formed on the surface of the second substrate; A cutout is formed in the protective layer to expose the metal protrusion.

8. The method for fabricating a heterogeneous integrated filter according to any one of claims 1-3, characterized in that, The first substrate is bonded to the bonding structure, including: A cavity is formed between the first substrate and the second substrate.

9. The method for fabricating a heterogeneous integrated filter according to any one of claims 1-3, characterized in that, The method of setting a resonator on the surface of the first substrate includes: A bottom electrode layer, a piezoelectric layer, and an upper electrode layer are sequentially stacked on the surface of the first substrate.

10. The method for fabricating a heterogeneous integrated filter according to any one of claims 1-3, characterized in that, The first substrate and the second substrate are bonded together by the bonding structure, including: The surfaces of the first substrate and the bonding structure to be bonded are cleaned and polished. The first substrate and the surfaces of the bonding structure to be bonded first come into contact, and then pressure is applied. Annealing is performed at a preset temperature.

11. The method for fabricating a heterogeneous integrated filter according to claim 10, characterized in that, The preset temperature is between 400-1200℃.

12. The method for fabricating a heterogeneous integrated filter according to any one of claims 1-3, characterized in that, The passive device includes one or a combination of capacitors, resistors, and inductors.

13. The method for fabricating a heterogeneous integrated filter according to claim 6, characterized in that, The insulating layer has an extension that extends from the upper surface of the bottom metal layer through its sidewall to the upper surface of the second substrate. A second metal connection line connected to the top metal layer is in contact with the top metal layer through the extension of the insulating layer, and the second metal connection line connected to the top metal layer is spaced from the bottom metal layer through the extension of the insulating layer.

14. The method for fabricating a heterogeneous integrated filter according to claim 8, characterized in that, At least a portion of the cavity is located between the resonator and the second substrate.

15. A heterogeneous integrated filter, characterized in that, It is prepared by any one of the preparation methods described in claims 1-14.

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