Semiconductor structure and method of bonding thereof

Abstract

The application relates to a semiconductor structure and a bonding method thereof, and relates to the technical field of semiconductors. The application first provides two substrates, the substrate comprises a groove and a conductive layer in the groove, the height of the conductive layer is smaller than the height of the groove in the direction perpendicular to the substrate, and a composite material layer is arranged on the conductive layer. The composite material is synthesized in situ in the direction of the conductive layer in the groove, the reaction condition can be controlled, the amount of the composite material generated is controlled, and the height of the conductive layer in the traditional process is not specially adjusted. The porous structure of the composite material can accommodate the thermal melting diffusion of the conductive layer in the bonding process, the metal penetration of the conductive layer into the substrate is prevented, and the conductive continuity is ensured through skeleton filling. The surface of the composite material layer is rich in functional groups, so that the bonding interface has the synergistic effect of dielectric material bonding and composite material bonding, the bonding strength is higher than that of the prior art, and the semiconductor structure formed by adopting the bonding method of the application has higher bonding strength and better reliability.

Description

Technical Field

[0001] This application relates to the field of semiconductor technology, and in particular to a semiconductor structure and a bonding method thereof. Background Technology

[0002] In packaging technology, high-density interconnects are achieved by embedding conductive metal nodes into dielectric materials and connecting them through bonding between dielectric materials and thermal diffusion connection of conductive metal nodes.

[0003] However, during the metal bonding process of semiconductor structures, due to the properties of the materials and the bonding process, it is easy for the conductive metal to fail to connect, or for the thermal expansion of the metal to diffuse into the conductive layer, resulting in risks such as reduced reliability. Summary of the Invention

[0004] Therefore, it is necessary to provide a semiconductor structure and its bonding method to address the issue of how to improve the bonding effect.

[0005] To achieve the above objectives, in one aspect, the present invention provides a bonding method for semiconductor structures, comprising:

[0006] Two substrates are provided, each substrate including a groove and a conductive layer located within the groove, wherein the height of the conductive layer is less than the height of the groove in a direction perpendicular to the substrate;

[0007] A composite material layer is grown in situ on the conductive layer, the composite material layer fills the groove, and the surface of the composite material layer has a variety of functional groups;

[0008] The two substrates are bonded together, wherein the composite material layers are disposed opposite each other and the functional groups are bonded together.

[0009] In one embodiment, prior to the step of growing the composite material layer in situ on the conductive layer, the method includes:

[0010] Measure the first height H between the surface of the conductive layer on the side away from the substrate and the surface of the substrate on the side where the groove is provided;

[0011] The number of composite material layers N is calculated based on the first height H to quantitatively grow the composite material layers. The calculation formula is as follows:

[0012]

[0013] Wherein, L is the thickness of each composite material layer in the direction perpendicular to the substrate.

[0014] In one embodiment, the composite material layer has a porous skeleton structure.

[0015] In one embodiment, after the step of bonding the two substrates, the method includes:

[0016] Annealing is performed to allow the particles of the conductive layer to diffuse into the composite material layer.

[0017] In one embodiment, the step of growing the composite material layer in situ on the conductive layer includes:

[0018] The substrate is treated in an alcoholic organic solution containing conjugated organic ligands to grow the composite material layer containing the conjugated organic ligands in situ on the conductive layer, wherein the conjugated organic ligands have a variety of the aforementioned functional groups.

[0019] In one embodiment, the step of growing the composite material layer in situ on the conductive layer includes:

[0020] The substrate is placed in an alcoholic organic solution containing conjugated organic ligands and magnetic materials for treatment, so as to grow the composite material layer containing the conjugated organic ligands and magnetic materials in situ on the conductive layer, wherein the conjugated organic ligands have a variety of functional groups.

[0021] In one embodiment, the step of bonding the two substrates includes:

[0022] A magnetic field is applied to the composite material layer containing the magnetic material to perform self-alignment of the substrate;

[0023] The self-aligned substrate is then bonded.

[0024] In one embodiment, the magnetic material comprises a metal compound of Fe, Co, or Ni.

[0025] In one embodiment, prior to the step of bonding the two substrates, the method includes:

[0026] The surface of the substrate to which the composite material layer is disposed is subjected to plasma treatment.

[0027] On the other hand, a semiconductor structure is also provided, which is fabricated using any of the bonding methods described above.

[0028] Compared with existing technologies, the above technical solution has the following unexpected technical features:

[0029] In this semiconductor structure and its bonding method, two substrates are first provided. Each substrate includes a groove and a conductive layer located within the groove. The height of the conductive layer is less than the height of the groove in the direction perpendicular to the substrate. A composite material layer is disposed on the conductive layer. This composite material is synthesized in situ and directionally on the conductive layer within the groove. This allows for control of reaction conditions and the amount of composite material generated, eliminating the need for precise height adjustment of the conductive layer in traditional processes. The porous structure of the composite material can accommodate the thermal diffusion of the conductive layer during bonding, preventing metal penetration into the substrate while ensuring conductive continuity through framework filling. The abundant functional groups on the surface of the composite material layer enable the bonding interface to possess the synergistic effect of both dielectric material bonding and composite material bonding, resulting in higher bonding strength than existing methods. The bonding method of this application can form semiconductor structures with higher bonding strength and better reliability. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a flowchart illustrating a bonding method for a semiconductor structure provided in an embodiment of this application.

[0032] Figure 2 This application provides a schematic diagram of a substrate structure.

[0033] Figure 3 This application provides a schematic diagram of the structure after forming a composite material layer structure.

[0034] Figure 4 This application provides a schematic diagram of the structure after substrate bonding;

[0035] Figure 5 This application provides a schematic diagram of a structure in which a magnetic field is applied during substrate bonding, as described in an embodiment of the present application.

[0036] Figure 6 This application provides a schematic diagram of the structure of a substrate bonded in a magnetic field.

[0037] Explanation of reference numerals in the attached figures: 01-substrate, 01a-substrate; 01b-dielectric layer; 02-groove; 03-conductive layer; 04-composite material layer. Detailed Implementation

[0038] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0040] It should be understood that when a layer is referred to as "on," "adjacent to," or "connected to" other layers, it can be directly on, adjacent to, or connected to other layers, or there can be intervening layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," or "directly connected to" other layers, there are no intervening layers.

[0041] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising,” “including,” or “having,” etc., specify the presence of the stated feature, whole, step, operation, component, part, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof.

[0042] Based on the content in the background art, the applicant found that controlling the height difference between the conductive layer and the groove is difficult when bonding semiconductor devices. This causes the conductive layer to fail to connect when the height difference is large, and the conductive layer to expand and diffuse into the substrate when the height difference is small, which further leads to low reliability of the bonded semiconductor device.

[0043] Based on this, this application provides a semiconductor structure and its bonding method. In this semiconductor structure and bonding method, two substrates are first provided. Each substrate includes a groove and a conductive layer located within the groove. In the direction perpendicular to the substrate, the height of the conductive layer is less than the height of the groove. A composite material layer is disposed on the conductive layer. This composite material is directionally synthesized in situ on the conductive layer within the groove, allowing for control of reaction conditions and the amount of composite material generated, eliminating the need for precise height adjustment of the conductive layer in traditional processes. The porous structure of the composite material can accommodate the thermal diffusion of the conductive layer during bonding, preventing metal penetration of the conductive layer into the substrate while ensuring conductive continuity through framework filling. The abundant functional groups on the surface of the composite material layer enable the bonding interface to possess the synergistic effect of both dielectric material bonding and composite material bonding, resulting in higher bonding strength than existing methods. The bonding method of this application can form semiconductor structures with higher bonding strength and better reliability.

[0044] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, this application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0045] Please refer to Figure 1 , Figure 1 This application provides a schematic flowchart of a semiconductor structure bonding method, which includes the following steps:

[0046] Step S10: Provide two substrates 01, each substrate 01 including a groove 02 and a conductive layer 03 located within the groove 02. In a direction perpendicular to the substrate 01, the height of the conductive layer 03 is less than the height of the groove 02 (e.g., ...). Figure 2 (As shown).

[0047] In this step, the two substrates 01 can be identical, and the structure does not need to be differentiated. Substrate 01 may include a silicon substrate 01a and a dielectric layer 01b stacked together, with the groove 02 located on the side of the dielectric layer 01b away from the substrate 01a. The conductive layer 03 can be made of copper, and there is no specific limitation on its material.

[0048] It should be noted that a conductive material layer can be formed in the groove 02 by deposition, and then part of the conductive material layer in the groove 02 can be removed so that the height of the conductive material layer in the direction perpendicular to the substrate 01 is less than the height of the groove 02, so as to obtain the conductive layer 03. That is, the groove 02 is not completely filled, leaving some space for the subsequent growth of composite materials.

[0049] It should be noted that when partially removing the conductive material layer here, there is no specific limitation on the thickness, which eliminates the need for height adjustment of the conductive layer 03 in the traditional process, making the preparation of the conductive layer 03 simpler.

[0050] Step S20: A composite material layer 04 is grown in situ on the conductive layer 03. The composite material layer 04 fills the groove 02, and the surface of the composite material layer 04 has a variety of functional groups (such as... Figure 3 (As shown).

[0051] In this step, the composite material layer 04 can be directionally grown in situ on the conductive layer 03. That is, the various functional groups in the composite material layer 04 that are easy to bond and interconnect can only form bonds with the conductive layer 03, but cannot form on the substrate 01.

[0052] The in-situ growth method forms a composite material layer 04 only on the conductive layer 03. Forming the composite material layer 04 allows for the control of reaction conditions, the amount of composite material generated, and the thickness of the final layer. This reduces both material waste and the number of preparation steps.

[0053] It should be noted that the various functional groups on the surface of composite layer 04 that are easy to bond and interconnect can include, but are not limited to, carboxylic acid groups, hydroxyl groups, alkyl groups, etc.

[0054] Step S30: Bond the two substrates 01 together, wherein the composite material layer 04 is positioned opposite each other and functional groups are bonded (e.g., ...). Figure 4 (As shown).

[0055] In this step, when the two substrates 01 are bonded, the substrates 01 are positioned opposite each other, and the composite material layer 04 is also positioned opposite each other to ensure that the substrates 01 and the composite material layer 04 are aligned. The composite material layer 04 fills the groove 02 through in-situ growth. Due to the porous structure of the composite material, the porous structure can accommodate the thermal diffusion of the conductive layer 03 during the bonding process, which not only prevents the conductive metal from penetrating the substrate, but also ensures the continuity of conductivity through the skeleton filling. The composite material layer 04 does not diffuse into the spaces between the substrates 01, increasing the reliability of the device. Furthermore, because the surface of the composite material layer 04 has various functional groups, hydrogen bonds, covalent bonds, ionic bonds, and coordination bonds are formed between the functional groups, resulting in a higher bonding strength than existing bonding methods and a more reliable structure.

[0056] In this embodiment, two substrates 01 are first provided. Each substrate 01 includes a groove 02 and a conductive layer 03 located within the groove 02. The height of the conductive layer 03 is less than the height of the groove 02 in the direction perpendicular to the substrate 01. A composite material layer 04 is disposed on the conductive layer 03. This composite material is synthesized in situ in a directional manner on the conductive layer 03 within the groove 02, allowing for control of reaction conditions and the amount of composite material generated, eliminating the need for special height adjustment of the conductive layer 03 in traditional processes. The porous structure of the composite material can accommodate the thermal diffusion of the conductive layer 03 during bonding, preventing metal penetration into the substrate while ensuring conductive continuity through framework filling, thus reducing reliability risks. The abundant functional groups on the surface of the composite material layer 04 enable the bonding interface to possess the synergistic effect of both dielectric material bonding and composite material bonding, resulting in higher bonding strength than existing methods. The bonding method of this application can form semiconductor structures with higher bonding strength and better reliability.

[0057] In another embodiment of this application, before the composite material layer 04 is grown in situ on the conductive layer 03, the following is included:

[0058] Step S100: Measure the first height H (e.g., ) between the surface of the conductive layer 03 away from the substrate 01 and the surface of the substrate 01 on the side where the groove 02 is provided. Figure 2 (as shown)

[0059] Step S101: Calculate the number of composite material layers N based on the first height H to quantitatively grow composite material layers 04. The calculation formula is as follows:

[0060]

[0061] Where L is the thickness of each composite material layer 04 in the direction perpendicular to the substrate 01.

[0062] Specifically, the existing conductive layer 03 has difficulty in height control in the direction perpendicular to the substrate 01. Therefore, in this application, the height of the conductive layer 03 is not adjusted. After removing part of the conductive material layer, the sidewall of part of the groove 02 is exposed. The conductive layer 03 can be formed at any height. Then, the first height H between the surface of the conductive layer 03 away from the substrate 01 and the surface of the substrate 01 with the groove 02 is measured, which is the height of the area in the groove 02 that is not filled by the conductive layer 03. Then, a composite material layer 04 is grown in situ on the surface of the conductive layer 03 away from the substrate 01. At this time, the composite material layer 04 can be grown quantitatively, thus eliminating the need for special height adjustment of the conductive layer 03 in the traditional process.

[0063] The quantitative growth of composite material layer 04 can include calculating the number of layers N of composite material layer 04 according to a calculation formula to quantitatively grow composite material layer 04, where N > 1 and N is a natural number. For example, the number of layers of composite material layer 04 can be 3 layers, or the number of layers of composite material layer 04 can be 5 layers, etc., without specific limitations. In this case, since the thickness of composite material layer 04 is quantitatively grown, its height can be controlled to be parallel to the substrate 01, ultimately achieving the filling of groove 02. This reduces the difficulty of controlling the height of conductive layer 03 in the direction perpendicular to substrate 01.

[0064] In one embodiment, the height of each composite material layer 04 in the direction perpendicular to the substrate 01 can range from 4 angstroms to 7 angstroms, including endpoint values. For example, the height of each composite material layer 04 in the direction perpendicular to the substrate 01 may be 4 angstroms, or the height of each composite material layer 04 in the direction perpendicular to the substrate 01 may be 5 angstroms, or the height of each composite material layer 04 in the direction perpendicular to the substrate 01 may be 7 angstroms, etc., without specific limitation.

[0065] It should be noted that the number of composite material layer 04 can be accurately calculated according to the calculation formula, and then the reaction conditions such as reaction time and temperature can be adjusted to control the amount of in-situ grown composite material layer 04, further avoiding material waste.

[0066] In another embodiment of this application, before bonding the two substrates 01, the following steps are included:

[0067] Plasma treatment is performed on the surface of the substrate 01 where the composite material layer 04 is provided.

[0068] Specifically, bonding the two substrates 01 requires bonding not only the composite material layer 04 but also the substrates 01. Before bonding the substrates 01, plasma treatment can be used to activate the surface of the substrates 01 where the composite material layer 04 is located, generating hydroxyl groups between the substrates 01 and promoting the formation of silicon-oxygen bonds, thus enabling covalent bonding. In this case, because the groove 02 contains the composite material layer 04, compared to existing metal filling methods, the problem of metal particle spatter is avoided during plasma treatment, improving the yield of the semiconductor structure.

[0069] In this embodiment, plasma treatment allows the substrate 01 to achieve covalent bonding, thereby increasing the bonding strength.

[0070] In another embodiment of this application, the composite material layer 04 is a porous skeleton structure.

[0071] In another embodiment of this application, after bonding the two substrates 01, the process includes:

[0072] Annealing is performed to allow the particles of conductive layer 03 to diffuse into composite material layer 04.

[0073] Specifically, the composite material layer 04 can be a porous skeleton structure, meaning that there are spaces between the composite material layers 04. During bonding, even if the conductive layer 03 is thermally melted and diffused, it will diffuse into the composite material layer 04. This not only prevents the metal of the conductive layer 03 from penetrating into the dielectric layer 01b of the substrate 01, but also ensures the continuity of conductivity through the porous skeleton structure.

[0074] In some embodiments, annealing is performed during the bonding of the substrate 01, which allows the material of the conductive layer 03 to expand, thereby filling the composite material layer 04 with a porous framework structure, increasing the bonding strength, and further ensuring the continuity of conductivity.

[0075] In some embodiments, the annealing temperature can be in the range of 100℃-200℃, including the endpoint values. For example, the annealing temperature can be 100℃, or 130℃, or 160℃, etc., without specific limitations. Since composite material layer 04 is used, the annealing temperature does not need to be set too high, and bonding of composite material layer 04 can be achieved at low temperatures. Low-temperature bonding is also easier to achieve.

[0076] In this embodiment, the porous skeleton composite material layer 04 can be annealed to achieve higher bonding strength and ensure the reliability of the device.

[0077] In another embodiment of this application, the in-situ growth of the composite material layer 04 on the conductive layer 03 includes:

[0078] The substrate 01 is placed in an alcoholic organic solution containing conjugated organic ligands for treatment, so as to grow a composite material layer 04 containing conjugated organic ligands in situ on the conductive layer 03. The conjugated organic ligands have a variety of functional groups.

[0079] Specifically, the conjugated organic ligands have a variety of functional groups that are easy to bond and interconnect. The substrate 01 is placed in an alcohol organic solution containing the conjugated organic ligands, and then a composite material layer 04 is formed in situ in the area where the conductive layer 03 contacts the solution by means of hydrothermal, stirring, microwave, ultrasonic, or ionothermal methods. The composite material layer 04 formed at this time has a variety of functional groups that are easy to bond and interconnect.

[0080] Conjugated organic ligands include, but are not limited to, carboxylic acid ligands, such as terephthalic acid (BDC) and trimesic acid (BTC); nitrogen-containing heterocyclic organic ligands, such as 2-methylimidazole and 4,4-bipyridine; and multidentate mixed organic ligands, such as triphenylamine (TCA) and triphenylmethane (TCM). It should be noted that various easily bonded and interconnected functional groups can only bond with the metal of conductive layer 03. Therefore, in-situ growth can only be performed on conductive layer 03 without affecting the substrate 01, thus ensuring the growth position of composite material layer 04.

[0081] In this embodiment, the conjugated organic ligand and the metal of the conductive layer 03 form a composite material layer 04. Since the conjugated organic ligand has a variety of functional groups that are easy to bond and interconnect, the surface of the composite material layer 04 has a variety of functional groups. The abundant functional groups on the surface of the composite material layer 04 enable the bonding interface to have the synergistic effect of dielectric material bonding and composite material bonding at the same time, which is higher than the existing bonding strength.

[0082] In another embodiment of this application, the in-situ growth of the composite material layer 04 on the conductive layer 03 includes:

[0083] The substrate 01 is placed in an alcoholic organic solution containing conjugated organic ligands and magnetic materials for treatment, so as to grow a composite material layer 04 containing conjugated organic ligands and magnetic materials in situ on the conductive layer 03. The conjugated organic ligands have a variety of functional groups.

[0084] In another embodiment of this application, the magnetic material includes a metal compound of Fe, Co, or Ni.

[0085] Specifically, the substrate 01 is placed in an alcoholic organic solution containing conjugated organic ligands and magnetic materials, and then a composite material layer 04 is formed in the area where the conductive layer 03 contacts the solution by means of hydrothermal, stirring, microwave, ultrasonic, or ionothermal methods.

[0086] Conjugated organic ligands include, but are not limited to, carboxylic acid ligands, such as terephthalic acid (BDC) and trimesic acid (BTC); nitrogen-containing heterocyclic organic ligands, such as 2-methylimidazole and 4,4-bipyridine; and multidentate mixed organic ligands, such as triphenylamine (TCA) and triphenylmethane (TCM). Magnetic materials include metal compounds of Fe, Co, or Ni materials, without specific limitations.

[0087] It should be noted that the conjugated organic ligands possess a variety of functional groups that are easily bonded and interconnected. These conjugated organic ligands can bond with both the metal and magnetic metals of the conductive layer 03. Due to the addition of magnetic materials, the composite material layer 04 becomes magnetic. Thus, the resulting composite material layer 04 possesses both a variety of easily bonded and interconnected functional groups and magnetic properties.

[0088] In this embodiment, the composite material layer 04, which incorporates conjugated organic ligands and magnetic materials, not only possesses a variety of functional groups that are easy to bond and interconnect, but also improves the alignment accuracy of the bonding.

[0089] In another embodiment of this application, bonding the two substrates 01 includes:

[0090] Step 301: Apply a magnetic field to the composite material layer 04 containing magnetic material to perform self-alignment of the substrate 01 (e.g., Figure 5 (as shown)

[0091] Step 302: Bond the self-aligned substrate 01 (e.g.) Figure 6 (As shown).

[0092] Specifically, before bonding substrate 01, substrate 01 can be placed in a magnetic field. Applying the magnetic field allows the composite material layers 04 containing magnetic materials in the upper and lower opposing substrates 01 to achieve magnetic self-alignment, thereby enabling substrate 01 to form self-alignment. Bonding of substrate 01 is then performed after self-alignment. This can reduce alignment deviations during bonding and improve device reliability.

[0093] Based on the bonding method of the semiconductor structure described above, this application also provides a semiconductor structure, which is made by the bonding method of any of the above embodiments, and its structure corresponds to the bonding method of the semiconductor structure described above.

[0094] The semiconductor structure includes two substrates 01, each substrate 01 comprising a groove 02 and a conductive layer 03 located within the groove 02. In a direction perpendicular to the substrate 01, the height of the conductive layer 03 is less than the height of the groove 02. A composite material layer 04 is disposed on the conductive layer 03. This composite material is synthesized in situ and directionally on the conductive layer 03 within the groove 02, allowing for control of reaction conditions and the amount of composite material generated, eliminating the need for precise height adjustment of the conductive layer 03 in traditional processes. The porous structure of the composite material can accommodate the thermal diffusion of the conductive layer 03 during bonding, preventing metal penetration into the substrate while ensuring conductive continuity through framework filling, thus reducing reliability risks. The abundant functional groups on the surface of the composite material layer 04 enable the bonding interface to possess the synergistic effect of both dielectric material bonding and composite material bonding, resulting in higher bonding strength than existing methods. The bonding method described in this application can form semiconductor structures with higher bonding strength and better reliability.

[0095] In the description of this specification, references to terms such as "some embodiments," "another embodiment," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0096] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features of the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0097] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A bonding method for a semiconductor structure, characterized in that, include: Two substrates are provided, each substrate including a groove and a conductive layer located within the groove, wherein the height of the conductive layer is less than the height of the groove in a direction perpendicular to the substrate; A composite material layer is grown in situ on the conductive layer, the composite material layer fills the groove, the composite material layer has a porous skeleton structure, and the surface of the composite material layer has a variety of functional groups. The two substrates are bonded together, wherein the composite material layers are disposed opposite each other and the functional groups are bonded together; Annealing is performed to allow the particles of the conductive layer to diffuse into the composite material layer.

2. The bonding method according to claim 1, characterized in that, Prior to the step of growing the composite material layer in situ on the conductive layer, the method includes: Measure the first height H between the surface of the conductive layer on the side away from the substrate and the surface of the substrate on the side where the groove is provided; The number of composite material layers N is calculated based on the first height H to quantitatively grow the composite material layers. The calculation formula is as follows: Wherein, L is the thickness of each composite material layer in the direction perpendicular to the substrate.

3. The bonding method according to claim 1, characterized in that, The step of growing the composite material layer in situ on the conductive layer includes: The substrate is treated in an alcoholic organic solution containing conjugated organic ligands to grow the composite material layer containing the conjugated organic ligands in situ on the conductive layer, wherein the conjugated organic ligands have a variety of the aforementioned functional groups.

4. The bonding method according to claim 1, characterized in that, The step of growing the composite material layer in situ on the conductive layer includes: The substrate is placed in an alcoholic organic solution containing conjugated organic ligands and magnetic materials for treatment, so as to grow the composite material layer containing the conjugated organic ligands and magnetic materials in situ on the conductive layer, wherein the conjugated organic ligands have a variety of functional groups.

5. The bonding method according to claim 4, characterized in that, The step of bonding the two substrates includes: A magnetic field is applied to the composite material layer containing the magnetic material to perform self-alignment of the substrate; The self-aligned substrate is then bonded.

6. The bonding method according to claim 4, characterized in that, The magnetic material includes metal compounds of Fe, Co, or Ni.

7. The bonding method according to claim 1, characterized in that, Prior to the step of bonding the two substrates, the following steps are included: The surface of the substrate to which the composite material layer is disposed is subjected to plasma treatment.

8. A semiconductor structure, characterized in that, The semiconductor structure is fabricated using the bonding method described in any one of claims 1-7.

Images