Bonding method, packaging method, bonding structure and packaging structure

Abstract

The invention discloses a bonding method, a packaging method, a bonding structure and a packaging structure, and the bonding method comprises the steps: providing a first bonding surface comprising an inorganic matter layer and a plurality of first metal structures, and a second bonding surface comprising a polymer layer and a plurality of second metal structures, and bonding the first bonding surface and the second bonding surface, and meanwhile, metal-metal bonding and inorganic matter-polymer dielectric bonding are formed. Therefore, in the bonding method provided by the embodiment of the invention, the flexibility of the polymer is utilized to improve the robustness and the interface quality in the bonding process, and the rigidity of the inorganic substance layer is utilized to ensure the stability of the structure, so that the bonding quality of the heterogeneous dielectric substance of the polymer layer and the inorganic substance layer is relatively high, and the metal bonding quality is indirectly improved; and high-reliability and high-yield hybrid bonding can be realized.

Description

Technical Field

[0001] The invention relates to the semiconductor field, and more particularly to a bonding method, a packaging method, a bonding structure, and a packaging structure. Background Technology

[0002] With the continuous development of cutting-edge technologies such as high-performance computing (High Bandwidth Memory) and artificial intelligence (AI), the amount of data generated and processed by various application scenarios is growing exponentially.

[0003] Against this backdrop, memory bandwidth performance, as a key component directly affecting core computing power metrics, has gradually become a bottleneck restricting the overall performance improvement of the system. To address this challenge, high-bandwidth memory technology has emerged, maximizing data transmission bandwidth within a limited chip area, thus becoming a key technological path to improve overall computing power.

[0004] In current technological practices for improving HBM storage capacity and bandwidth, increasing the number of vertical stacking layers of dynamic random access memory (DRAM) chips through advanced packaging technology is the industry-recognized mainstream technical solution. In order to achieve high-density vertical stacking and reliable electrical interconnection between multi-layer DRAM chips, existing advanced packaging products such as HBM3 and HBM3E generally adopt an interconnect architecture that combines through silicon vias (TSVs) and micro-bumps. However, there is still room for further improvement in micro-bump interconnect technology. Summary of the Invention

[0005] This invention provides a bonding method, a packaging method, a bonding structure, and a packaging structure to improve the manufacturing yield and process stability of the packaging structure.

[0006] To address the aforementioned problems, the present invention provides a bonding method, comprising: providing a first bonding surface, the first bonding surface comprising an inorganic layer and a plurality of first metal structures; providing a second bonding surface, the second bonding surface comprising a polymer layer and a plurality of second metal structures; bonding the first bonding surface and the second bonding surface to form a metallic bond between the first metal structures and the second metal structures, and to form a dielectric bond between the inorganic layer and the polymer layer.

[0007] The present invention provides a method for forming a package structure, comprising: providing a device wafer, the device wafer including a first bonding surface, the first bonding surface including an inorganic layer and a plurality of first metal structures; providing a first package, the first package including a second bonding surface, the second bonding surface including a polymer layer and a plurality of second metal structures; bonding the first bonding surface of the device wafer and the second bonding surface of the first package to form a metal bond between the first metal structures and the second metal structures, and forming a dielectric bond between the inorganic layer and the polymer layer.

[0008] The present invention also provides a bonding structure, comprising: a first bonding surface, the first bonding surface including an inorganic layer and a plurality of first metal structures; and a second bonding surface bonded to the first bonding surface, the second bonding surface including a polymer layer and a plurality of second metal structures, wherein the first metal structures and the second metal structures constitute a metallic bond, and the inorganic layer and the polymer layer constitute a dielectric bond.

[0009] The present invention also provides a packaging structure, comprising: a device package body including a first bonding surface, the first bonding surface including an inorganic layer and a plurality of first metal structures; and a first package body bonded to the device package body, the first package body including a second bonding surface, the second bonding surface including a polymer layer and a plurality of second metal structures, wherein the first metal structures and the second metal structures form a metal bond, and the inorganic layer and the polymer layer form a dielectric bond.

[0010] Compared with the prior art, the technical solution of the invention has the following advantages:

[0011] The bonding method provided in this invention provides a first bonding surface comprising an inorganic layer and multiple first metal structures, and a second bonding surface comprising a polymer layer and multiple second metal structures. By bonding the first and second bonding surfaces, metal-to-metal bonding and inorganic-polymer dielectric bonding are simultaneously formed. Firstly, the polymer layer has a lower Young's modulus and higher elasticity and viscoelasticity than the inorganic layer. Therefore, during the bonding process of the first and second bonding surfaces, the polymer layer can effectively absorb and buffer bonding pressure and better adapt to the microscopic irregularities on the surface of the inorganic layer in the first bonding surface. This results in a larger tolerance window for the inorganic-polymer dielectric bonding, which in turn facilitates a more uniform and comprehensive contact between the first and second metal structures, improving the quality of the metal bonding formation. Secondly, the polymer layer is relatively soft, and its flexibility provides stress buffering during the bonding process. Conversely, the inorganic layer is relatively hard, and its rigidity provides stable mechanical support for the entire bonded structure. This prevents collapse or excessive deformation during the bonding of the inorganic and polymer layers, ensuring the structural stability of the structure after bonding the first and second bonding surfaces. Therefore, the bonding method provided in this embodiment utilizes the flexibility of the polymer to improve the robustness and interface quality of the bonding process, and the rigidity of the inorganic layer to ensure structural stability. This results in high-quality heterodielectric bonding between the polymer and inorganic layers, indirectly improving the quality of metal bonding and contributing to the achievement of highly reliable and high-yield hybrid bonding.

[0012] In the method for forming the packaging structure provided in this embodiment of the invention, the device wafer includes a first bonding surface, which includes an inorganic layer and a first metal structure. The first package includes a second bonding surface, which includes a polymer layer and a second metal structure. The first bonding surface of the device wafer and the second bonding surface of the first package are bonded together, simultaneously forming a metal-metal bond between the first and second metal structures, and an inorganic-polymer dielectric bond between the inorganic layer and the polymer. This embodiment of the invention utilizes an asymmetric interface material, specifically a rigid inorganic layer with a high Young's modulus bonded to a polymer layer with a low Young's modulus. Because the polymer layer has higher elasticity and viscoelasticity, it can effectively absorb and buffer bonding pressure during the bonding process of the first and second bonding surfaces. It can also better adapt to the microscopic unevenness on the surface of the inorganic layer in the first bonding surface, resulting in a larger tolerance window for the dielectric bonding of inorganic-polymer materials. Consequently, the bonding process window from the first package to the device wafer (Chip-to-Wafer) is expanded. In addition, the high quality of the heterogeneous dielectric bonding between the polymer layer and the inorganic layer also indirectly improves the quality of metal bonding, enabling reliable electrical interconnection between different device wafers and the first package, which is beneficial to improving the manufacturing yield and process stability of the package structure. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0014] Figure 1 This is a flowchart of the bonding method according to an embodiment of the present invention;

[0015] Figures 2 to 5 This is a schematic diagram of the structure corresponding to the bonding method in an embodiment of the present invention;

[0016] Figures 6 to 12 This is a schematic diagram of the method for forming the packaging structure according to an embodiment of the present invention. Detailed Implementation

[0017] As the background technology indicates, while microbump interconnect technology brings performance improvements, its inherent physical characteristics also bring its development to a bottleneck, leading to a series of pressing technical problems. On the one hand, the existing microbump technology has limited interconnect pitch shrinkage capabilities, typically ranging from 25 to 50 micrometers, making it difficult to economically and stably reduce to below 20 micrometers. This directly restricts further increases in interconnect density, thus becoming a major obstacle to achieving another leap in next-generation HBM bandwidth. On the other hand, in the chip stacking process using microbumps, underfill material must be filled into the gaps between the microbumps between chip layers. This filling step not only increases the overall stack thickness of the HBM chip, thus limiting the total number of stackable DRAM layers, but also increases the thermal resistance of the chip stack due to the typically low thermal conductivity of the fill material. This hinders the effective conduction of core heat outwards, negatively impacting the heat dissipation performance of the entire chip system.

[0018] Therefore, the bottlenecks in existing technologies regarding interconnect density, stacking thickness, and heat dissipation efficiency can no longer meet the future development requirements of HBM and chip packaging technologies for higher integration.

[0019] Currently, mainstream bumpless hybrid bonding technologies primarily employ metal / inorganic dielectric material systems such as copper / silicon dioxide (Cu / SiO2). Essentially, this involves using chemical mechanical polishing (CMP) to obtain an ultra-smooth bonding surface, followed by high-precision alignment, bonding, and thermal annealing to achieve direct copper-copper metal interconnects. While this approach theoretically increases interconnect density by two orders of magnitude with extremely low signal loss, it faces a series of severe technical challenges and drawbacks in actual industrial-scale fabrication. First, this technology places extremely stringent requirements on the surface quality of the bonding interface. The CMP process must construct a surface with atomically flatness; any minute roughness or morphological defects will severely affect the bonding strength and may even lead to bonding failure. Second, in the interface construction, the height difference between the copper (Cu) and the dielectric layer (SiO2), i.e., the depth of the copper disc-shaped depression, must be strictly controlled. The control precision of the copper content has reached the single-atom-layer level, resulting in an extremely narrow process window. Furthermore, the entire fabrication process is highly sensitive to environmental cleanliness; contamination from a single microparticle can cause voids at the bonding interface, directly leading to device failure. Therefore, in general, existing Cu / inorganic dielectric hybrid bonding schemes face significant challenges in process development and yield control due to their extreme dependence on surface quality, complex and costly surface treatment and fabrication procedures (such as damascus steel and PECVD), and the substantial investment required for high-precision, high-cost equipment. These factors constitute the main technical bottlenecks hindering their widespread application.

[0020] To address the aforementioned technical problems, the bonding method provided in this invention provides a first bonding surface comprising an inorganic layer and multiple first metal structures, and a second bonding surface comprising a polymer layer and multiple second metal structures. By bonding the first and second bonding surfaces, metal-to-metal bonding and inorganic-polymer dielectric bonding are simultaneously formed. Firstly, the polymer layer has a lower Young's modulus and higher elasticity and viscoelasticity than the inorganic layer. Therefore, during the bonding process of the first and second bonding surfaces, the polymer layer can effectively absorb and buffer bonding pressure and better adapt to the microscopic irregularities on the surface of the inorganic layer in the first bonding surface. This results in a larger tolerance window for the inorganic-polymer dielectric bonding, which in turn facilitates a more uniform and comprehensive contact between the first and second metal structures, improving the quality of the metal bonding formation. Secondly, the polymer layer is relatively soft, and its flexibility provides stress buffering during the bonding process. Conversely, the inorganic layer is relatively hard, and its rigidity provides stable mechanical support for the entire bonded structure. This prevents collapse or excessive deformation during the bonding of the inorganic and polymer layers, ensuring the structural stability of the structure after bonding the first and second bonding surfaces. Therefore, the bonding method provided in this embodiment utilizes the flexibility of the polymer to improve the robustness and interface quality of the bonding process, and the rigidity of the inorganic layer to ensure structural stability. This results in high-quality heterodielectric bonding between the polymer and inorganic layers, indirectly improving the quality of metal bonding and contributing to the achievement of highly reliable and high-yield hybrid bonding.

[0021] The technical solutions in the disclosed embodiments will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the invention, and not all embodiments. Based on the embodiments of the invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the invention.

[0022] Accordingly, the present invention also provides a method for forming an encapsulation structure. Figure 1 This is a flowchart of the bonding method according to an embodiment of the present invention; Figures 2 to 5 This is a schematic diagram of the bonding method according to an embodiment of the present invention.

[0023] Combination Figure 1 ,refer to Figure 2 A first bonding surface 10 is provided, the first bonding surface 10 including an inorganic layer 11 and a plurality of first metal structures 12.

[0024] The first bonding surface 10 is used to bond with the second bonding surface 20, and the inorganic layer 11 is bonded with the corresponding polymer layer 21, and the first metal structure 12 is bonded with the corresponding second metal structure 22.

[0025] In some embodiments, the inorganic layer 11 has a high Young's modulus, and during the subsequent bonding process of the first bonding surface 10 and the second bonding surface 20, the inorganic layer 11 can suppress the deformation or collapse of the bonded structure.

[0026] In some embodiments, during the step of providing the first bonding surface 10, the inorganic layer 11 comprises silicon carbonitride (SiCN).

[0027] Silicon carbonitride (SiCN) is rich in carbon (C), which provides higher stiffness and stronger interfacial bonding force for the bonding interface between the subsequent inorganic layer 11 and polymer layer 21. Therefore, the use of SiCN not only enables the subsequently formed bonding structure to have strong mechanical support, but also provides favorable surface conditions for achieving strong dielectric-dielectric chemical bonding, thereby improving the strength and stability of the entire hybrid bonding and facilitating the realization of reliable heterogeneous material interface interconnection.

[0028] refer to Figure 3 A second bonding surface 20 is provided, the second bonding surface 20 including a polymer layer 21 and a plurality of second metal structures 22.

[0029] The polymer layer 21 of the second bonding surface 20 has a lower Young's modulus and higher elasticity and viscoelasticity, which can effectively absorb and buffer external pressure during the bonding process. This allows it to better adapt to the microscopic unevenness of the inorganic layer 11 surface or accommodate small particles, which relaxes the requirements for the flatness and cleanliness of the first bonding surface 10 and the second bonding surface 20, thereby increasing the tolerance window of the bonding process.

[0030] In some embodiments, in the step of providing the first bonding surface 10, the first metal structure 12 is recessed in the surface of the inorganic layer 11; in the step of providing the second bonding surface 20, the second metal structure 22 protrudes from the surface of the polymer layer 21.

[0031] By constructing a recessed first metal structure 12 on the relatively rigid inorganic layer 11 and a matching protruding second metal structure 22 on the flexible polymer layer 21, a microscopic "mortise and tenon" structure can be formed between the first metal structure 12 and the second metal structure 22 when the first bonding surface 10 and the second bonding surface 20 are bonded. This mechanical locking mechanism prevents lateral displacement during the bonding process. Therefore, in the bonding process of the first bonding surface 10 and the second bonding surface 20, in addition to metal-metal bonding and polymer-inorganic chemical bonding, a mechanical locking structure is introduced to further improve the shear resistance and peel resistance between the first bonding surface 10 and the second bonding surface 20, which is beneficial to improving the reliability of the bonding structure under thermal cycling or mechanical impact.

[0032] In other embodiments, the first metal structure may protrude from the surface of the inorganic layer in the step of providing the first bonding surface; and the second metal structure may be recessed into the surface of the polymer layer in the step of providing the second bonding surface.

[0033] In some embodiments, during the step of providing the first bonding surface 10, the Young's modulus of the polymer layer 21 is lower than that of the inorganic layer 11.

[0034] The high Young's modulus of the inorganic layer 11 is used to construct a stable structural framework, thereby preventing the collapse of the polymer-inorganic bonding structure under bonding pressure. The low Young's modulus of the polymer layer 21 provides higher elasticity and viscoelasticity, which can act as a stress buffer, effectively absorbing and buffering bonding pressure. It can also better adapt to the microscopic unevenness on the surface of the inorganic layer 11 in the first bonding surface 10, so that the dielectric bonding of the inorganic-polymer has a larger tolerance window. This is conducive to forming a more uniform and comprehensive contact between the first metal structure 12 and the second metal structure 22, thereby improving the formation quality of the metal bonding.

[0035] In some embodiments, during the step of providing the first bonding surface, the Young's modulus of the inorganic layer is between 70 GPa and 300 GPa, for example, 100 GPa or 200 GPa. During bonding, the inorganic layer acts as a rigid support to address potential collapse or deformation of the viscoelastic polymer layer under bonding pressure. If the Young's modulus of the inorganic layer is below 70 GPa, its stiffness is insufficient, and under the heat and pressure applied during bonding, it is prone to undesirable plastic deformation or creep. This disrupts the smoothness of the bonding interface between the inorganic and polymer layers, making it impossible for the first metal structure to maintain its depth within the inorganic layer, which is detrimental to the formation of a stable interconnect structure between the first and second metal structures. If the Young's modulus of the inorganic layer is above 300 GPa, the inorganic layer becomes brittle. Under the heat and pressure required for bonding, even small stress concentrations, such as localized high stress caused by uneven bonding pressure or the presence of small particles at the interface, can easily lead to cracking or brittle fracture of the inorganic layer. This contradicts the original intention of this invention to improve process robustness and reduce failure risk by introducing the flexibility of polymers.

[0036] In some embodiments, the Young's modulus of the polymer layer is between 0.1 GPa and 3 GPa, for example, 1 GPa or 2 GPa. When the Young's modulus of the polymer layer is below 0.1 GPa, the polymer layer is relatively soft and lacks the necessary mechanical strength and shape stability. Under pressure and temperature, the polymer layer is close to a viscous fluid rather than a solid. When the first metal structure and the second metal structure are bonded, the size of the second metal structure protruding from the polymer layer cannot be controlled, which is not conducive to the formation of a stable interconnect structure between the first metal structure and the second metal structure. If the Young's modulus of the polymer layer is higher than 3 GPa, it means that the polymer layer is too hard and does not have the flexible buffering capacity. In this case, the bonding process will again become a direct contact between two high-modulus rigid surfaces.

[0037] In some embodiments, in the step of providing the first bonding surface 10, the first metal structure 12 is recessed 2 to 5 nanometers in the surface of the inorganic layer 11; in the step of providing the second bonding surface 20, the second metal structure 22 protrudes 10 to 30 nanometers from the surface of the polymer layer 21.

[0038] The size of the second metal structure 22 protruding from the surface of the polymer layer 21 is significantly larger than the size of the first metal structure 12 recessed into the surface of the inorganic layer 11. This allows the protruding second metal structure 22 to have sufficient margin to embed into the recessed first metal structure 12 when the first bonding surface 10 and the second bonding surface 20 are bonded. This also compensates for the deformation of the polymer under pressure and heat. In other words, even if the polymer layer 21 undergoes large thermal expansion, it will not affect the high-quality metal-metal bonding between the protruding second metal structure 22 and the recessed first metal structure 12, which helps to maximize the bonding strength and ensure the integrity of the electrical connection.

[0039] In some embodiments, the polymer layer 21 is made of a polymer material having a predetermined low coefficient of thermal expansion (CTE).

[0040] By selecting a polymer material with a low coefficient of thermal expansion, the interfacial stress caused by thermal mismatch is suppressed during the temperature rise and fall of the bonding process and the thermal cycle during chip operation. This reduces the risk of interface delamination, cracking, or fatigue failure of the first metal structure 12 and the second metal structure 22 caused by stress. Therefore, the polymer layer 21 is made of a polymer material with a preset low coefficient of thermal expansion (CTE), which helps to reduce the thermomechanical stress inside the bonding structure and makes the bonding structure thermally reliable.

[0041] As an example, in the step of providing the second bonding surface, the material of the polymer layer includes polyimide.

[0042] In some embodiments, in the step of providing the first bonding surface 10, the first metal structure 12 includes pads; in the step of providing the second bonding surface 20, the second metal structure 22 includes pads. Both the first metal structure 12 and the second metal structure 22 include pads, which are electrical interconnection paths between the first bonding surface 10 and the second bonding surface 20.

[0043] In some embodiments, the first metal structure 12 adopts... <111> The second metal structure 22 is a nanotwinned copper with a crystalline phase. <111> Nanotwinned copper with crystalline phase.

[0044] The first metal structure 12 and the second metal structure 22 adopt the following: <111> Nanotwinned copper with a crystalline phase, meaning the pads use a type of... <111> Nanotwinned copper (Nt-Cu) with crystalline phase has <111> The crystalline phase of nanotwinned copper has an extremely high atomic diffusion rate, which can promote the rapid diffusion of copper atoms across the bonding interface at relatively low temperatures, thereby achieving dense, void-free copper-copper metal bonding. This is beneficial for achieving low-temperature bonding of the first bonding surface 10 and the second bonding surface 20, which significantly reduces the thermal budget of the bonding process, helps to reduce the impact on temperature-sensitive device structures, and improves bonding efficiency.

[0045] In some embodiments, before bonding the first bonding surface 10 and the second bonding surface 20, the first bonding surface 10 is treated to form hydroxyl dangling bonds on the surface of the inorganic layer 11.

[0046] The pre-formation of high-density hydroxyl (-OH) dangling bonds on the surface of inorganic layer 11 is to prepare for the subsequent bonding of polymer and inorganic materials. By transforming the originally chemically inert inorganic surface into a highly reactive surface, the necessary conditions are provided for the subsequent chemical reaction with the functional groups on the polymer surface.

[0047] In some embodiments, the step of forming hydroxyl dangling bonds on the surface of the inorganic layer 11 includes: performing an alkaline chemical wet treatment on the surface of the inorganic layer 11.

[0048] During the alkaline chemical wet treatment of the inorganic layer 11 surface, the alkaline solution reacts with the inorganic layer 11 surface to generate hydroxyl functional groups. This can uniformly introduce a high density of active sites across the entire dielectric surface, preparing for subsequent chemical reactions with functional groups on the polymer surface.

[0049] In some embodiments, the step of performing alkaline chemical wet treatment on the surface of the inorganic layer 11 includes treatment with ammonia water.

[0050] Ammonia (NH3·H2O) is used as the reagent for alkaline chemical wet treatment. Ammonia is a mature application in semiconductor technology and can react with inorganic dielectric materials such as SiCN to generate hydroxyl dangling bonds on the surface of inorganic layer 11 without damaging the material.

[0051] It should be noted that the step of forming hydroxyl dangling bonds on the surface of the inorganic layer 11 includes: before performing alkaline chemical wet treatment on the surface of the inorganic layer 11, subjecting the first bonding surface 10 to plasma bombardment to remove oxides on the surface of the first metal structure 12, and performing surface activation on the inorganic layer 11.

[0052] Plasma bombardment of the first bonding surface 10 removes oxides from the surface of the first metal structure 12 and simultaneously slightly etches and activates the surface of the inorganic dielectric layer 11, increasing its surface energy. A clean surface environment also prevents metal oxides from contaminating and interfering with the subsequent alkaline wet process, and improves the surface energy of the entire bonding surface. It also provides a highly clean and active surface state for subsequent bonding, allowing subsequent copper-copper diffusion interconnects to occur on a clean metal interface, avoiding oxides from hindering the formation of metal bonds. Therefore, plasma bombardment of the first bonding surface 10 is a dual guarantee for ensuring the electrical performance of metal bonding and the chemical activity of dielectric bonding, which is conducive to achieving high-quality hybrid bonding.

[0053] In some embodiments, the plasma bombardment is a bombardment using a plasma containing argon (Ar) and hydrogen (H2).

[0054] Argon and hydrogen are specially added to the plasma. Ar plasma mainly removes surface contaminants and oxide layers through physical sputtering, thus achieving physical cleaning. H2 plasma, through its strong reducing properties, reacts chemically with metal oxides to achieve chemical reduction cleaning. Therefore, the mixed plasma of argon and hydrogen combines the advantages of physical and chemical cleaning, making the removal of oxides on the copper surface more thorough and without residue, thus preparing for subsequent bonding.

[0055] In some embodiments, the bonding method further includes: before bonding the first bonding surface 10 and the second bonding surface 20, treating the second bonding surface 20 to form a carboxyl (-COOH) functional group on the surface of the polymer layer 21.

[0056] Carboxyl functional groups are pre-formed on the surface of polymer layer 21. By transforming the relatively chemically stable polymer surface into a surface containing active functional groups, it is made capable of chemically reacting with the hydroxyl groups on the surface of inorganic layer 11, thus preparing for the subsequent formation of strong chemical bonds between polymer and inorganic materials.

[0057] In some embodiments, the step of forming carboxyl functional groups on the surface of the polymer layer 21 includes: subjecting the surface of the polymer layer 21 to acidic catalytic activation treatment.

[0058] Acidic catalytic activation treatment of the polymer layer 21 is one way to achieve carboxylation of the polymer layer 21 surface. By utilizing the acidic environment to catalyze the chemical changes of polymer surface molecules to generate carboxyl functional groups, the desired chemically active sites can be introduced into the flexible polymer surface, preparing for subsequent chemical reactions with hydroxylated inorganic surfaces.

[0059] In some embodiments, the step of performing acidic catalytic activation treatment on the surface of the polymer layer 21 includes treatment with citric acid.

[0060] Citric acid is used as the reagent for acidic catalytic activation treatment. Citric acid is a mild organic acid that can catalyze the formation of carboxyl groups on the surface of polymer layer 21 without severely corroding polymer layer 21 and the second metal structure 22, thereby achieving selective surface modification. In addition, citric acid itself contains multiple carboxyl groups, and while catalyzing the reaction on the polymer surface, it may also adsorb or graft onto the polymer surface, directly increasing the carboxyl group density on the surface. Therefore, the use of citric acid makes the activation process of the polymer surface both safe and effective.

[0061] In some embodiments, the step of forming carboxyl functional groups on the surface of the polymer layer 21 includes: removing oxides on the surface of the second metal structure 22 by plasma bombardment of the second bonding surface 20 before acid catalytic activation treatment of the surface of the polymer layer 21, and surface activation of the polymer layer 21.

[0062] Plasma bombardment of the second bonding surface 20 efficiently removes the oxide layer on the surface of the second metal structure 22, preparing it for subsequent metal bonding. Furthermore, plasma bombardment can slightly etch and modify the surface of the polymer layer 21, activating it, breaking some polymer chains, increasing surface roughness and active sites, and improving the reactivity of the polymer layer 21 surface. Therefore, plasma bombardment of the second bonding surface 20 achieves simultaneous optimization of the second metal structure 22 and the polymer layer 21, improving the cleanliness and chemical activity of the second bonding surface 20, which is beneficial for promoting the simultaneous formation of both metal-metal and inorganic-polymer bonds.

[0063] In some embodiments, the plasma bombardment is a bombardment using a plasma containing Ar and H2.

[0064] Combination Figure 1 ,refer to Figure 5 The first bonding surface 10 and the second bonding surface 20 are bonded together to form a metal bond between the first metal structure 12 and the second metal structure 22, and a dielectric bond is formed between the inorganic layer 11 and the polymer layer 21.

[0065] The bonding method provided in this embodiment of the invention provides a first bonding surface 10 comprising an inorganic layer 11 and a plurality of first metal structures 12, and a second bonding surface 20 comprising a polymer layer 21 and a plurality of second metal structures 22. By bonding the first bonding surface 10 and the second bonding surface 20, metal-metal bonding and inorganic-polymer dielectric bonding are formed simultaneously. First, the polymer layer 21 has a lower Young's modulus and higher elasticity and viscoelasticity than the inorganic layer 11. Therefore, during the bonding process of the first bonding surface 10 and the second bonding surface 20, the polymer layer 21 can effectively absorb and buffer the bonding pressure and better adapt to the microscopic unevenness on the surface of the inorganic layer 11 in the first bonding surface 10. This results in a larger tolerance window for the inorganic-polymer dielectric bonding, which is beneficial for forming a more uniform and comprehensive contact between the first metal structures 12 and the second metal structures 22, thereby improving the quality of metal bonding formation. Secondly, the polymer layer 21 is relatively soft, and its flexibility provides stress buffering during the bonding process. Conversely, the inorganic layer 11 is relatively rigid, and its rigidity provides stable mechanical support for the entire bonded structure. This prevents collapse or excessive deformation during the bonding of the inorganic layer 11 and the polymer layer 21, ensuring the structural stability after the first bonding surface 10 and the second bonding surface 20 are bonded. Therefore, the bonding method provided in this embodiment utilizes the flexibility of the polymer to improve the robustness and interface quality of the bonding process, and utilizes the rigidity of the inorganic layer 11 to ensure structural stability. This results in high-quality heterodielectric bonding between the polymer layer 21 and the inorganic layer 11, and indirectly improves the quality of metal bonding, contributing to the achievement of highly reliable and high-yield hybrid bonding.

[0066] In some embodiments, the step of bonding the first bonding surface 10 and the second bonding surface 20 includes: setting the first bonding surface 10 and the second bonding surface 20 opposite to each other, such that the first metal structure 12 corresponds to the second metal structure 22, and the inorganic layer 11 corresponds to the polymer layer 21; and applying a preset temperature and a preset pressure to the first bonding surface 10 and the second bonding surface 20.

[0067] With the first metal structure 12 corresponding to the second metal structure 22, and the inorganic layer 11 corresponding to the polymer layer 21, a preset temperature and a preset pressure are applied to the first bonding surface 10 and the second bonding surface 20. The pressure is a prerequisite for ensuring close contact between the first metal structure 12 and the second metal structure 22, as well as between the inorganic layer 11 and the polymer layer 21. The temperature provides the activation energy required for atomic diffusion and chemical reaction. Therefore, the synergy of alignment, temperature, and pressure is the core element for achieving mixed bonding of the first bonding surface 10 and the second bonding surface 20, which is beneficial to ensuring the bonding yield of the first bonding surface 10 and the second bonding surface 20.

[0068] In some embodiments, in the step of applying a preset temperature and a preset pressure to the first bonding surface and the second bonding surface, the preset temperature is lower than or equal to 200°C, for example, 100°C or 150°C. On one hand, the materials of the first metal structure 12 and the second metal structure 22 are nanotwinned copper, which possesses excellent diffusion properties, providing a material basis for achieving effective solid-phase diffusion between metal atoms at lower temperatures. On the other hand, the material of the polymer layer 21 has a low Young's modulus and high elasticity and viscoelasticity, which not only ensures that the bonding interface can achieve a tight, gapless physical bond under pressure, but also provides favorable conditions for the movement of polymer molecular chains. Therefore, during the bonding process, while the nanotwinned copper diffuses to form a reliable electrical interconnect, the molecular chains of the polymer layer 21 can fully entangle with the surface of the inorganic layer 11 and form a stable chemical bond. It is this synergistic mechanism of metal diffusion and inorganic-polymer interface bonding that enables the entire hybrid bonding process to be completed efficiently at lower temperatures, thereby effectively avoiding the negative impact that high-temperature processes may have on the structures of other precision devices on the chip.

[0069] In some embodiments, in the step of applying a preset temperature and a preset pressure to the first bonding surface and the second bonding surface, the preset pressure is between 50N and 100N, for example, 60N or 70N. If the preset pressure is less than 50N, it will result in insufficient contact between the first bonding surface and the second bonding surface. For example, the first metal structure and the second metal structure cannot achieve a tight contact, resulting in an open circuit between the first metal structure and the second metal structure. In addition, it will also cause the flexible polymer layer to fail to undergo the necessary micro-deformation to completely fill and adhere to the rigid SiCN surface. This will result in small gaps between the polymer layer and the inorganic layer, making it difficult to form a large bonding force. Moreover, these gaps will also become interface voids, affecting the sealing performance and long-term reliability of the bonding structure. If the preset pressure is greater than 100N, excessive stress will be concentrated on the inorganic dielectric layer, causing microcracks in the inorganic dielectric layer, damaging the insulation, and even causing a short circuit. Excessive pressure will also cause excessive plastic deformation of the first and second metal structures, causing the part of the second metal structure protruding from the polymer layer to be flattened, destroying the "mortise and tenon" shape designed to achieve reliable interlocking.

[0070] refer to Figures 6 to 12 The present invention also provides a method for forming an encapsulation structure.

[0071] refer to Figure 6 A device wafer 100 is provided, the device wafer 100 including the first bonding surface 10 as described in the foregoing embodiments, the first bonding surface 10 including an inorganic layer 11 and a plurality of first metal structures 12.

[0072] The device wafer 100 provides a mechanical support basis for the formation method of the packaging structure, wherein the first bonding surface 10 is used to bond with the second bonding surface 20, the inorganic layer 11 is bonded with the subsequent polymer layer 21, and the first metal structure 12 is bonded with the subsequent second metal structure 22.

[0073] As an example, Figure 6The structure of the device wafer 100 is illustrated. The steps of providing the device wafer 100 include: providing a third substrate 101; forming a metal pillar 103 penetrating the third substrate 101; forming a third metal layer 102 on top of the metal pillar 103; forming a third dielectric stack covering the third substrate 101, the metal pillar 103, and the third metal layer 102, the third dielectric stack including: a first dielectric layer 104, an inorganic layer 11, and a second dielectric layer (not shown) stacked sequentially; etching the third dielectric stack with the top of the third metal layer 102 as the etching stop position, forming a third trench (not shown) in the third dielectric stack; forming a conductive material on the surface of the third trench and the third dielectric stack; removing the conductive material layer above the inorganic layer 11 and the second dielectric layer with the top of the inorganic layer 11 as the planarization stop position, the remaining conductive material located in the third trench serving as a first metal structure 12, the top of the first metal structure 12 being recessed.

[0074] In some embodiments, the material of the first dielectric layer 104 includes silicon oxide, the material of the inorganic layer 11 includes silicon carbonitride, and the material of the second dielectric layer includes silicon oxide.

[0075] In some embodiments, the third dielectric stack is etched using a dry etching process to form a third trench in the third dielectric stack.

[0076] In some embodiments, the materials of the third metal layer 102, the metal pillar 103, and the first metal structure 12 all include copper.

[0077] In some embodiments, an electrochemical plating (ECP) process is used to form a conductive material on the surface of the third trench and the third dielectric stack.

[0078] In some embodiments, a chemical mechanical polishing (CMP) process is used to remove the conductive material layer above the inorganic layer 11 and the second dielectric layer.

[0079] It should be noted that in the step of providing device wafer 100, the device wafer 100 includes multiple spaced-apart unit regions, and each unit region forms a logic chip to be divided.

[0080] The logic chip is used to perform logical operations and control tasks such as control, timing management, address decoding, and data buffering. A first bonding surface 10 is formed on the surface of the logic chip for bonding with the subsequent first package (memory chip) to achieve high-density, low-latency electrical interconnection, thereby receiving data from the memory chip or sending instructions to it.

[0081] It should be noted that, on the side of the logic chip facing away from the first bonding surface 10, after exposing the metal pillars 103 through a backside via reveal (BVR) process, redistribution layer (RDL) micro-bumps are applied, enabling the bottom logic chip to establish electrical and physical connections with external systems (such as GPUs, CPUs, or packaging substrates). The logic chip not only manages the read and write operations of the memory chip but also acts as a bridge, converting and facilitating communication between the internal high-bandwidth data stream and the external system's bus.

[0082] refer to Figure 7 A first package 200 is provided, the first package 200 including the second bonding surface 20 as described in the foregoing embodiments, the second bonding surface 20 including a polymer layer 21 and a plurality of second metal structures 22.

[0083] The first package 200 includes a second bonding surface 20. The polymer layer 21 of the second bonding surface 20 has a low Young's modulus and high elasticity and viscoelasticity. Thus, during the bonding process of the first package 200 to the first bonding surface 10 of the device wafer 100, it can effectively absorb and buffer the externally applied pressure, thereby better adapting to the microscopic unevenness of the inorganic layer 11 surface or accommodating small particles. This relaxes the requirements for the flatness and cleanliness of the first bonding surface 10 and the second bonding surface 20, thereby increasing the tolerance window of the bonding process.

[0084] In some embodiments, reference Figure 8 The first bonding surface 10 of the device wafer 100 and the second bonding surface 20 of the first package 200 are bonded together, so that a metal bond is formed between the first metal structure 12 and the second metal structure 22, and a dielectric bond is formed between the inorganic layer 11 and the polymer layer 21.

[0085] In the method for forming the packaging structure provided in this embodiment of the invention, the device wafer 100 includes a first bonding surface 10, which includes an inorganic layer 11 and a first metal structure 12. The first package 200 includes a second bonding surface 20, which includes a polymer layer 21 and a second metal structure 22. The first bonding surface 10 of the device wafer 100 and the second bonding surface 20 of the first package 200 are bonded together, simultaneously forming a metal-metal bond between the first metal structure 12 and the second metal structure 22, and an inorganic-polymer dielectric bond between the inorganic layer 11 and the polymer. This embodiment of the invention utilizes an asymmetric interface material, specifically bonding a rigid inorganic layer 11 with a high Young's modulus to a polymer layer 21 with a low Young's modulus. Because the polymer layer 21 has higher elasticity and viscoelasticity, it can effectively absorb and buffer bonding pressure during the bonding process of the first bonding surface 10 and the second bonding surface 20. It can also better adapt to the microscopic unevenness on the surface of the inorganic layer 11 in the first bonding surface 10, so that the dielectric bonding of inorganic material-polymer has a larger tolerance window. Correspondingly, the bonding process window from the first package 200 to the device wafer 100 (Chip-to-Wafer) is expanded. In addition, the high quality of the heterogeneous dielectric bonding between the polymer layer 21 and the inorganic layer 11 also indirectly improves the quality of metal bonding, enabling reliable electrical interconnection between different device wafers 100 and the first package 200, which is beneficial to improving the manufacturing yield and process stability of the packaging structure.

[0086] In some embodiments, the first package 200 is a DRAM (Dynamic Random Access Memory) chip, and the first package 200 is the main unit for implementing High Bandwidth Memory (HBM) functionality.

[0087] In some embodiments, in the step of providing a first package 200, the first package 200 includes a first side A and a second side B facing away from each other, a first bonding surface 10 is formed in the first side A, and a second bonding surface 20 is formed in the second side B; the method of forming the package structure further includes: providing a second package 300, on which a second bonding surface 20 is formed, the second bonding surface 20 including a polymer layer 21 and a plurality of second metal structures 22; after providing the second package 300, bonding the first bonding surface 10 of the first package 200 and the second bonding surface 20 of the second package 300 together (e.g., ...). Figure 11 As shown), a metallic bond is formed between the first metal structure 12 and the second metal structure 22, and a dielectric bond is formed between the inorganic layer 11 and the polymer layer 21.

[0088] The first package 200 has a first bonding surface 10 and a second bonding surface 20. By constructing a rigid first bonding surface 10 on one side and a flexible second bonding surface 20 on the other side, the second bonding surface 20 of the first package 200 is bonded to the first bonding surface 10 of the device wafer 100, and the first bonding surface 10 of the first package 200 is bonded to the second bonding surface 20 of the second package 300. This allows the device wafer 100, the first package 200 and the second package 300 to have a stable stacked structure while also achieving reliable electrical connection.

[0089] In some embodiments, in the step of providing a first package 200, there are multiple first packages 200, and the multiple first packages 200 are stacked, with the first bonding surface 10 in the lower first package 200 bonding with the second bonding surface 20 in the upper first package 200.

[0090] The first package 200 has a first bonding surface 10 on one side and a second bonding surface 20 on the other side. By vertically stacking multiple first packages 200 with double-sided asymmetric bonding interfaces, the heterogeneous bonding modes of metal-metal and "inorganic-polymer" are replicated and extended in the stacking direction, thereby constructing a high-density memory chip stack. Therefore, the stacking method of the first package 200 can be directly applied to advanced packaging products (such as HBM) that require multi-layer core chip stacking, enabling memory chips to be tightly integrated, significantly shortening the signal interconnection path, and facilitating the realization of high-performance computing chips with higher bandwidth, lower latency, and lower power consumption.

[0091] HBM technology is one of the core methods to increase total capacity and bandwidth by increasing the number of memory layers. The first package has a first bonding surface 10 and a second bonding surface 20 on its two sides, which are optimized for this purpose. Combined with the metal pillars 103 (through silicon vias, TSVs) that penetrate the first substrate vertically in the first package 200, vertical transmission of signals and power can be achieved between adjacent first packages 200. Each first package 200 contributes a portion of the memory capacity, and all first packages 200 are addressed and controlled by the bottom logic chip through the metal pillars 103.

[0092] refer to Figure 7The step of providing the first package 200 includes: providing a first substrate 201, the first substrate 201 including a first side A and a second side B opposite to each other, the first side A of the first substrate 201 having a first metal layer 202 and a metal pillar 203 located below the first metal layer 202; forming a first dielectric stack (not shown in the figure) on the first side A of the first substrate 201, the first dielectric stack including: a first dielectric layer 2041, an inorganic layer 11 and a second dielectric layer (not shown in the figure) stacked sequentially; etching the first dielectric stack with the top of the first metal layer 202 as the etching stop position, forming a first trench (not shown in the figure) in the first dielectric stack; and forming a trench (not shown in the figure) in the first trench. A conductive material (not shown) is formed on the surface of the first dielectric layer and the inorganic layer 11. Taking the top of the inorganic layer 11 as the planarization stop position, the conductive material above the inorganic layer 11 and the second dielectric layer (not shown) are removed, and the remaining conductive material in the first trench serves as the first metal structure 12. The top of the first metal structure 12 is recessed. A back-side via exposure process is performed on the second side B to expose the metal pillar 203 of the second side B. A second metal structure 22 is formed on the metal pillar 203 of the second side B. A polymer layer 21 is formed on the second side B, covering part of the sidewall of the second metal structure 22. The second metal structure 22 protrudes from the polymer layer 21.

[0093] By employing damascus steeling and CMP processes on the first side A of the first substrate 201, a recessed first metal structure 12 is fabricated in the rigid inorganic layer 11. Simultaneously, on the other side, a metal pillar 203 is exposed through a back-view via (BVR) process. A second metal structure 22 is formed on the metal pillar 203 on the second side B, protruding from the polymer layer 21. Therefore, both a "mortise" structure (recess) and a "tenon" structure (protrusion) are simultaneously formed on the first package 200. Consequently, the first package 200 provides a structural basis for realizing a microscopic "mortise and tenon" interconnection mechanical self-locking mechanism. This increases the interlocking force on the structure, which not only relies on metal diffusion and chemical bonding during chip stacking but also significantly enhances the mechanical strength and shear resistance of the bonding interface, thereby improving the long-term reliability of the package structure.

[0094] In some embodiments, the step of forming a polymer layer 21 covering a portion of the sidewall of the second metal structure 22 on the second side B includes: forming a polymer material layer covering the second metal structure 22 on the second side B; curing the polymer material layer; planarizing the cured polymer material layer with the top of the second metal structure 22 as the planarization stop position, removing the polymer material layer higher than the second metal structure 22; etching a portion of the thickness of the polymer material layer to form a polymer layer 21 covering the sidewall of the second metal structure 22.

[0095] By first planarizing and then re-etching the polymer layer 21, the protrusion height of the second metal structure 22 relative to the surface of the polymer layer 21 can be precisely controlled. This ensures that the height of the second metal structure 22 protruding from the polymer layer 21 matches the recess depth of the first metal structure 12 relative to the inorganic layer 11, as well as the thermal expansion coefficient of the polymer and the bonding process parameters. This achieves "mortise and tenon interconnection," ensuring that when the first bonding surface 10 and the second bonding surface 20 are bonded, the protruding second metal structure 22 can align and contact with the recessed first metal structure 12 and undergo sufficient diffusion interconnection. This is beneficial for ensuring excellent electrical performance and a high bonding success rate.

[0096] In some embodiments, the step of forming a second metal structure 22 on the metal pillar 203 on the second side B includes: depositing a second dielectric stack 207 on the second side B; etching the second dielectric stack 207 to form a second trench in the second dielectric stack 207 exposing the metal pillar 203; and forming the second metal structure 22 in the second trench.

[0097] As an example, the second dielectric stack 207 includes a silicon nitride layer 2071 and a silicon oxide layer 2072 located on the silicon nitride layer 2071.

[0098] In some embodiments, in the step of providing a device wafer 100, the device wafer 100 includes a plurality of spaced-apart unit regions I, and the first bonding surface 10 is located on the surface of the unit region I; the method of forming the package structure includes: sequentially bonding a plurality of first package bodies 200 on the first bonding surface 10 of each unit region I; after sequentially bonding the plurality of first package bodies 200, bonding a second package body 300 on the topmost first package body 200; forming a molding compound 400 covering the device wafer 100, the first package body 200 and the second package body 300, the molding compound 400 exposing the surface of the second package body 300; and cutting the molding compound 400 and the device wafer 100 along the boundaries of adjacent unit regions I to form a plurality of package structures. This achieves a complete process flow from third substrate 101-level manufacturing to the final formation of independent package structures. It combines the bonding process of the first package 200 and the second package 300 with the device wafer 100 with the subsequent molding and dicing processes to form a complete, mass-producible packaging solution. This enables all high-precision hybrid bonding stacks to be completed on the device wafer 100, and then the stack is protected as a whole by molding. Therefore, this third substrate 101-level packaging (WLP) process can maximize the scale effect of third substrate 101 manufacturing, so that each package structure formed by the final dicing has highly consistent performance and reliability, which helps to reduce manufacturing costs and improve the overall yield of the final product.

[0099] It should be noted that the device wafer 100 is cut into device package 500.

[0100] As an example, see reference Figure 11 and Figure 12 The step of forming the molding compound 400 includes: forming a molding compound material layer 401 on the device wafer 100 that covers and stacks a first package 200 and a second package 300; taking the top of the second package 300 as the grinding stop position, removing the molding compound material layer 401 above the second package 300, and the remaining molding compound material layer 401 as the molding compound 400.

[0101] In some embodiments, the second package 300 has a second bonding surface on the side facing the first package 200. The second bonding surface includes a second metal structure 22 and a polymer layer 21. The second package 300 is used to enclose the stacked first package 200 and provide protection.

[0102] In some embodiments, Figure 9The diagram shows a structural schematic of the second package 300. The steps of providing the second package 300 include: providing a second substrate 301, on which a second metal layer 302 is formed; forming a second metal structure 22 on the second metal layer 302; and forming a polymer layer 21 on the second substrate 301 that covers a portion of the sidewalls of the second metal structure 22, wherein the second metal structure 22 protrudes from the polymer layer 21.

[0103] The second metal structure 22 in the second package 300 protrudes from the polymer layer 21. The polymer layer 21 and the second metal structure 22 serve as flexible bonding surfaces to facilitate bonding with the rigid bonding surface of the first package 200, so that they act as a "tenon" structure to cooperate with the "mortise" structure of the first package 200.

[0104] In some embodiments, the step of forming a second metal structure 22 on the second metal layer 302 includes: forming a third dielectric layer 303 covering the second metal layer 302 on the second substrate 301; etching the third dielectric layer 303 to form a first groove in the third dielectric layer 303 exposing the second metal layer 302; forming a seed layer 305 on the surface of the first groove and the third dielectric layer 303; forming a fourth dielectric layer on the second substrate 301 after forming the seed layer 305; etching the fourth dielectric layer to form a second groove (not shown in the figure) in the fourth dielectric layer; and forming the second metal structure 22 in the second groove.

[0105] As an example, the materials of the third dielectric layer 303 and the fourth dielectric layer include silicon oxide.

[0106] As an example, an electrochemical plating process is used to form a second metal structure 22 in the second groove.

[0107] In some embodiments, the step of forming a polymer layer 21 covering a portion of the sidewalls of the second metal structure 22 on the second substrate 301 includes: forming a polymer material layer covering the second metal structure 22 on the second substrate 301; curing the polymer material layer; planarizing the cured polymer material layer with the top of the second metal structure 22 as the planarization stop position, removing the polymer material layer above the second metal structure 22; etching a portion of the thickness of the polymer material layer to form a polymer layer 21 covering the sidewalls of the second metal structure 22.

[0108] As an example, a polymer material layer covering the second metal structure 22 is formed on the second substrate 301 using a coating process.

[0109] As an example, a chemical mechanical planarization process is used to remove the polymer material layer above the second metal structure 22.

[0110] refer to Figure 5 The present invention also provides a bonding structure, the bonding structure comprising: a first bonding surface 10, the first bonding surface 10 comprising an inorganic layer 11 and a plurality of first metal structures 12; and a second bonding surface 20 bonded to the first bonding surface 10, the second bonding surface 20 comprising a polymer layer 21 and a plurality of second metal structures 22, wherein the first metal structures 12 and the second metal structures 22 constitute a metallic bond, and the inorganic layer 11 and the polymer layer 21 constitute a dielectric bond.

[0111] The bonding structure provided in this embodiment of the invention forms both metal-metal bonding and inorganic-polymer dielectric bonding by bonding the first bonding surface 10 and the second bonding surface 20 together. Firstly, the polymer layer 21 has a lower Young's modulus and higher elasticity and viscoelasticity than the inorganic layer 11. Therefore, in the bonding structure of the first bonding surface 10 and the second bonding surface 20, the polymer layer 21 can effectively absorb and buffer the pressure during bonding and better adapt to the microscopic unevenness on the surface of the inorganic layer 11 in the first bonding surface 10. This results in a larger tolerance window for the inorganic-polymer dielectric bonding, which in turn facilitates a more uniform and comprehensive contact between the first metal structure 12 and the second metal structure 22, improving the quality of the metal bonding formation. Secondly, the polymer layer 21 is relatively soft, and its flexibility provides stress buffering for the bonding interface. Conversely, the inorganic layer 11 is relatively rigid, and its rigidity provides stable mechanical support for the entire bonding structure. This prevents collapse or excessive deformation during the bonding of the inorganic layer 11 and polymer layer 21, ensuring the stability of the resulting bonding structure. Therefore, the bonding structure provided in this embodiment utilizes the flexibility of the polymer to improve the robustness of the bonding process and the interface quality, and utilizes the rigidity of the inorganic layer 11 to ensure structural stability. This results in high-quality heterodielectric bonding between the polymer layer 21 and the inorganic layer 11, and indirectly improves the quality of metal bonding, contributing to the achievement of highly reliable and high-yield hybrid bonding.

[0112] In some embodiments, the first bonding surface 10 includes an inorganic layer 11 and a plurality of first metal structures 12.

[0113] In some embodiments, the inorganic layer 11 has a high Young's modulus, and the inorganic layer 11 can suppress deformation or collapse of the bonded structure.

[0114] In some embodiments, the inorganic layer 11 comprises silicon carbonitride.

[0115] The second bonding surface 20 includes a polymer layer 21 and multiple second metal structures 22. The polymer layer 21 of the second bonding surface 20 has a lower Young's modulus and higher elasticity and viscoelasticity, which can effectively absorb and buffer externally applied pressure, thereby better adapting to the microscopic unevenness of the inorganic layer 11 surface or accommodating small particles. This relaxes the requirements for the flatness and cleanliness of the first bonding surface 10 and the second bonding surface 20, thus increasing the tolerance window of the bonding process.

[0116] In some embodiments, the Young's modulus of the polymer layer 21 is lower than that of the inorganic layer 11.

[0117] The high Young's modulus of the inorganic layer 11 is used to construct a stable structural framework, thereby preventing the collapse of the polymer-inorganic bonding structure under bonding pressure. The low Young's modulus of the polymer layer 21 provides higher elasticity and viscoelasticity, which can act as a stress buffer, effectively absorbing and buffering bonding pressure. It can also better adapt to the microscopic unevenness on the surface of the inorganic layer 11 in the first bonding surface 10, so that the dielectric bonding of the inorganic-polymer has a larger tolerance window. This is conducive to forming a more uniform and comprehensive contact between the first metal structure 12 and the second metal structure 22, thereby improving the formation quality of the metal bonding.

[0118] In some embodiments, the polymer layer 21 is made of a polymer material with a coefficient of thermal expansion (CTE) of less than or equal to 50 ppm / K.

[0119] By selecting a polymer material with a coefficient of thermal expansion (CTE) of less than or equal to 50 ppm / K to make the polymer layer 21, the interfacial stress caused by thermal mismatch is suppressed during the heating and cooling process of bonding and the thermal cycling during chip operation. This reduces the risk of interface delamination, cracking, or fatigue failure of the first metal structure 12 and the second metal structure 22 caused by stress. Therefore, the polymer is made of a polymer material with a preset low coefficient of thermal expansion (CTE), which helps to reduce the thermomechanical stress inside the bonding structure and makes the bonding structure have long-term thermal reliability.

[0120] In some embodiments, the Young's modulus of the inorganic layer 11 is between 70 GPa and 300 GPa, for example, 100 GPa or 200 GPa. The inorganic layer acts as a rigid support to address potential collapse or deformation of the viscoelastic polymer layer during bonding. If the Young's modulus of the inorganic layer is below 70 GPa, its stiffness is insufficient, and under the heat and pressure applied during bonding, it is prone to undesirable plastic deformation or creep. This can disrupt the smoothness of the bonding interface between the inorganic and polymer layers, hindering the formation of a stable interconnect structure between the first and second metal structures. If the Young's modulus of the inorganic layer is above 300 GPa, the inorganic layer becomes brittle. Under the heat and pressure required for bonding, even small stress concentrations, such as localized high stress caused by uneven bonding pressure or the presence of small particles at the interface, can easily lead to cracking or brittle fracture of the inorganic layer. This contradicts the original intention of this invention to improve process robustness and reduce failure risk by introducing the flexibility of polymers.

[0121] In some embodiments, the Young's modulus of the polymer layer 21 is between 0.1 GPa and 3 GPa, for example, 1 GPa or 2 GPa. When the Young's modulus of the polymer layer is below 0.1 GPa, the polymer layer is relatively soft and lacks the necessary mechanical strength and shape stability. Under the influence of pressure and temperature during the bonding process, the polymer layer is close to a viscous fluid rather than a solid. When the first metal structure 11 and the second metal structure 12 are bonded, the size of the second metal structure 12 protruding from the polymer layer cannot be controlled, which is not conducive to the formation of a stable interconnect structure between the first metal structure 11 and the second metal structure 12. If the Young's modulus of the polymer layer is higher than 3 GPa, it means that the polymer layer is too hard and does not have the flexible buffering capacity. In this case, the bonding process will again become a direct contact between two high-modulus rigid surfaces.

[0122] In some embodiments, the polymer layer 21 is made of polyimide.

[0123] In some embodiments, the first metal structure 12 includes pads; the second metal structure 22 includes pads. Both the first metal structure 12 and the second metal structure 22 include pads, which are electrical interconnection paths between the first bonding surface 10 and the second bonding surface 20.

[0124] In some embodiments, the first metal structure 12 adopts... <111> The crystalline phase of nanotwinned copper, the second metal structure 22 adopts <111> Nanotwinned copper with crystalline phase.

[0125] The first metal structure 12 and the second metal structure 22 adopt the following: <111> Nanotwinned copper with a crystalline phase, meaning the pads use a type of... <111> Nanotwinned copper (Nt-Cu) with crystalline phase has <111> The crystalline phase of nanotwinned copper has an extremely high atomic diffusion rate, which can promote the rapid diffusion of copper atoms across the bonding interface at relatively low temperatures, thereby achieving dense, void-free copper-copper metal bonding. This is beneficial for achieving low-temperature bonding of the first bonding surface 10 and the second bonding surface 20, which significantly reduces the thermal budget of the bonding process, helps to reduce the influence of temperature-sensitive bonding structures, and improves bonding efficiency.

[0126] In some embodiments, at the interface between the polymer layer 21 and the inorganic layer 11, the surface of the polymer layer 21 includes carboxyl functional groups, and the surface of the inorganic layer 11 includes hydroxyl dangling bonds, with chemical bonds formed between the carboxyl functional groups and the hydroxyl dangling bonds. The formation of this chemical bond enhances the interfacial bonding force between the inorganic layer 11 and the polymer layer 21, thereby improving the strength and reliability of the dielectric bond.

[0127] Combination Figure 6 , Figure 7 and Figure 9 ,refer to Figure 12 The present invention also provides a packaging structure including: a device package 500, including a first bonding surface 10, the first bonding surface 10 including an inorganic layer 11 and a plurality of first metal structures 12; and a first package 200, bonded to the device package 500, the first package 200 including a second bonding surface 20, the second bonding surface 20 including a polymer layer 21 and a plurality of second metal structures 22, wherein the first metal structures 12 and the second metal structures 22 form a metal bond, and the inorganic layer 11 and the polymer layer 21 form a dielectric bond.

[0128] In the packaging structure provided by this embodiment of the invention, the device package 500 includes a first bonding surface 10, which includes an inorganic layer 11 and a first metal structure 12. The first package 200 includes a second bonding surface 20, which includes a polymer layer 21 and a second metal structure 22. The first bonding surface 10 of the device package 500 is bonded to the second bonding surface 20 of the first package 200, and simultaneously possesses metal-metal bonding between the first metal structure 12 and the second metal structure 22, as well as inorganic-polymer dielectric bonding between the inorganic layer 11 and the polymer layer 21. This embodiment of the invention utilizes an asymmetric interface material, specifically bonding a rigid inorganic layer 11 with a high Young's modulus to a polymer layer 21 with a low Young's modulus. Because the polymer layer 21 has higher elasticity and viscoelasticity, in the bonding structure that bonds the first bonding surface 10 and the second bonding surface 20, the polymer layer 21 can effectively absorb and buffer the bonding pressure and better adapt to the microscopic unevenness on the surface of the inorganic layer 11 in the first bonding surface 10. This results in a larger tolerance window for the dielectric bonding of the inorganic-polymer material, which in turn expands the bonding process window from the first package 200 to the device package 500 (Chip-to-Wafer). In addition, the high quality of the heterogeneous dielectric bonding between the polymer layer 21 and the inorganic layer 11 also indirectly improves the quality of the metal bonding, enabling reliable electrical interconnection between different device packages 500 and the first package 200. This is beneficial for improving the manufacturing yield and process stability of the packaging structure.

[0129] In some embodiments, the first package 200 includes a first side A and a second side B facing away from each other, the first side A including a first bonding surface 10, and the second side B including a second bonding surface 20; the package structure further includes a second package 300, the second package 300 including a second bonding surface 20, the second bonding surface 20 including a polymer layer 21 and a plurality of second metal structures 22; the first bonding surface 10 of the first package 200 and the second bonding surface 20 of the second package 300 are bonded together, so that a metal bond is formed between the first metal structure 12 and the second metal structure 22, and a dielectric bond is formed between the inorganic layer 11 and the polymer layer 21.

[0130] The first side A of the first package 200 has a rigid first bonding surface 10, and the second side B has a flexible second bonding surface 20. When the second bonding surface 20 of the first package 200 is bonded to the first bonding surface 10 of the device package 500, and the first bonding surface 10 of the first package 200 is bonded to the second bonding surface 20 of the second package 300, the device package 500, the first package 200 and the second package 300 have a stable stacked structure and also achieve reliable electrical connection.

[0131] In some embodiments, there are multiple first package bodies 200, and the multiple first package bodies 200 are stacked, with the first bonding surface 10 in the lower first package body 200 bonded to the second bonding surface 20 in the upper first package body 200.

[0132] The first package 200 has a first bonding surface 10 on its first side A and a second bonding surface 20 on its second side B. By vertically stacking multiple first packages 200 with double-sided asymmetric bonding interfaces, the heterogeneous bonding modes of metal-metal and "inorganic-polymer" are replicated and extended in the stacking direction, thereby constructing a high-density memory chip stack. Therefore, the stacking method of the first package 200 can be directly applied to advanced packaging products (such as HBM) that require multi-layer core chip stacking, enabling memory chips to be tightly integrated, significantly shortening signal interconnection paths, and facilitating the realization of high-performance computing chips with higher bandwidth, lower latency, and lower power consumption.

[0133] As an example, the first package 200 includes: a first substrate 201, the first substrate 201 including a first side A and a second side B facing away from each other, the first side A of the first substrate 201 having a first metal layer 202 and a metal pillar 203 located below the first metal layer 202; a first metal structure 12, on the first side A, located on top of the first metal layer 202; a first dielectric layer 2041, on the first side A, located on the first substrate 201 on the side of the first metal structure 12; an inorganic layer 11, located on the first dielectric layer 2041 on the side of the first metal structure 12, the inorganic layer 11 and the first dielectric layer 2041 completely covering the sidewall of the first metal structure 12; a second metal structure 22, on the second side B, located at the end of the metal pillar 203 facing away from the first metal layer 202; and a polymer layer 21, on the second side B, located on the first substrate 201 on the side of the second metal structure 22, and the polymer layer 21 covering part of the sidewall of the second metal structure 22.

[0134] In some embodiments, the first package 200 further includes a second dielectric stack 207 located on the second side B between the first substrate 201 and the polymer layer 21.

[0135] As an example, the second dielectric stack 207 includes a silicon nitride layer 2071 and a silicon oxide layer 2072 located between the silicon nitride layer 2071 and the polymer layer 21.

[0136] In some embodiments, the second package 300 includes: a second substrate 301 on which a second metal layer 302 is formed; a second metal structure 22 on the second metal layer 302; and a polymer layer 21 on the second substrate 301 on the side of the second metal structure 22, wherein the polymer layer 21 covers a portion of the sidewall of the second metal structure 22.

[0137] The polymer layer 21 and the second metal structure 22 in the second encapsulation 300 serve as flexible bonding surfaces, forming a bonding structure with the inorganic layer 11 and the first metal structure 12 of the first encapsulation 200, which serve as rigid bonding surfaces.

[0138] As an example, the second package 300 further includes: a third dielectric layer 303 located between the second substrate 301 and the polymer layer 21; and a seed layer 305 located between the second metal layer 302 and the second metal structure 22.

[0139] As an example, the device package 500 includes: a third substrate 101; a third metal layer 102 located on top of the third substrate 101; a metal pillar 103 located at the bottom of the third metal layer 102 and connected to the bottom of the third metal layer 102; a first metal structure 12 located on top of the third metal layer 102; a first dielectric layer 104 located on the third substrate 101, the third metal layer 102, and the metal pillar 103, and exposed on top of the first metal structure 12; and an inorganic layer 11 located on the first dielectric layer 104 on the side of the first metal structure 12.

[0140] The bonding structure can be formed using the bonding method described in the foregoing embodiments, or it can be formed using other methods. For a detailed description of the bonding structure described in this embodiment, please refer to the corresponding descriptions in the foregoing embodiments; these descriptions will not be repeated here.

[0141] The packaging structure can be formed using the forming method described in the foregoing embodiments, or it can be formed using other forming methods. For a detailed description of the packaging structure described in this embodiment, please refer to the corresponding descriptions in the foregoing embodiments; these descriptions will not be repeated here.

[0142] While the embodiments of the present invention have been disclosed above, the invention is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the invention should be determined by the scope defined in the claims.

Claims

1. A bonding method, characterized in that, include: A first bonding surface is provided, the first bonding surface comprising an inorganic layer and a plurality of first metallic structures; A second bonding surface is provided, the second bonding surface comprising a polymer layer and a plurality of second metal structures; The first bonding surface and the second bonding surface are bonded together to form a metallic bond between the first metal structure and the second metal structure, and a dielectric bond is formed between the inorganic layer and the polymer layer.

2. The bonding method as described in claim 1, characterized in that, In the step of providing the first bonding surface, the first metal structure is recessed in the inorganic layer; in the step of providing the second bonding surface, the second metal structure protrudes from the polymer layer. Alternatively, the first metal structure protrudes from the inorganic layer; in the step of providing the second bonding surface, the second metal structure is recessed into the polymer layer.

3. The bonding method as described in claim 1, characterized in that, In the step of providing the first bonding surface, the first metal structure is recessed 2 to 5 nanometers on the surface of the inorganic layer; In the step of providing the second bonding surface, the second metal structure protrudes 10 nanometers to 30 nanometers from the surface of the polymer layer.

4. The bonding method as described in claim 1, characterized in that, The steps of bonding the first bonding surface and the second bonding surface include: The first bonding surface and the second bonding surface are arranged opposite to each other, such that the first metal structure corresponds to the second metal structure, and the inorganic layer corresponds to the polymer layer. A preset temperature and a preset pressure are applied to the first bonding surface and the second bonding surface.

5. The bonding method as described in claim 4, characterized in that, In the step of applying a preset temperature and a preset pressure to the first bonding surface and the second bonding surface, the preset temperature is lower than or equal to 200°C, and the preset pressure is between 50N and 100N.

6. The bonding method as described in claim 1, characterized in that, The bonding method further includes: before bonding the first bonding surface and the second bonding surface, processing the second bonding surface to form carboxyl functional groups on the surface of the polymer layer; Before bonding the first bonding surface and the second bonding surface, the first bonding surface is treated to form hydroxyl dangling bonds on the surface of the inorganic layer.

7. The bonding method as described in claim 6, characterized in that, The step of forming carboxyl functional groups on the surface of the polymer layer includes: subjecting the surface of the polymer layer to acidic catalytic activation treatment; The step of forming hydroxyl dangling bonds on the surface of the inorganic layer includes: subjecting the surface of the inorganic layer to an alkaline chemical wet treatment.

8. The bonding method as described in claim 7, characterized in that, In the step of performing acidic catalytic activation treatment on the surface of the polymer layer, the acidic catalytic activation treatment includes treatment with citric acid.

9. The bonding method as described in claim 7, characterized in that, In the step of performing alkaline chemical wet treatment on the surface of the inorganic layer, the alkaline chemical wet treatment includes treatment with ammonia water.

10. The bonding method as described in claim 7, characterized in that, The step of forming carboxyl functional groups on the surface of the polymer layer includes: removing oxides from the surface of the second metal structure by plasma bombardment of the second bonding surface before acid catalytic activation treatment of the polymer layer surface, and surface activation of the polymer layer.

11. The bonding method as described in claim 7, characterized in that, The step of forming hydroxyl dangling bonds on the surface of the inorganic layer includes: removing oxides from the surface of the first metal structure by plasma bombardment of the first bonding surface before performing alkaline chemical wet treatment on the surface of the inorganic layer, and performing surface activation on the inorganic layer.

12. The bonding method as described in claim 11, characterized in that, The plasma bombardment is a bombardment using plasma containing Ar and H2.

13. The bonding method as described in claim 1, characterized in that, In the step of providing the first bonding surface, the first metal structure includes a bonding pad; In the step of providing the second bonding surface, the second metal structure includes a pad.

14. The bonding method as described in claim 1, characterized in that, The first metal structure adopts <111> Nanotwinned copper with crystalline phase; The second metal structure adopts <111> Nanotwinned copper with crystalline phase.

15. The bonding method as described in claim 1, characterized in that, In the step of providing the first bonding surface, the inorganic layer comprises silicon carbonitride.

16. The bonding method as described in claim 1, characterized in that, In the step of providing the second bonding surface, the polymer layer is made of a polymer material with a coefficient of thermal expansion of less than or equal to 50 ppm / K.

17. The bonding method as described in claim 1, characterized in that, In the step of providing the first bonding surface, the Young's modulus of the polymer layer is lower than that of the inorganic layer.

18. The bonding method as described in claim 17, characterized in that, In the step of providing the first bonding surface, the Young's modulus of the inorganic layer is 70 GPa to 300 GPa; In the step of providing the second bonding surface, the Young's modulus of the polymer layer is from 0.1 GPa to 3 GPa.

19. The bonding method as described in claim 1, characterized in that, In the step of providing the second bonding surface, the material of the polymer layer includes polyimide.

20. A method for forming an encapsulation structure, characterized in that, include: A device wafer is provided, the device wafer comprising a first bonding surface prepared by any one of claims 1 to 19, the first bonding surface comprising an inorganic layer and a plurality of first metal structures; A first package is provided, the first package including a second bonding surface prepared by any one of claims 1 to 19, the second bonding surface including a polymer layer and a plurality of second metal structures; the first bonding surface of the device wafer and the second bonding surface of the first package are bonded together, such that a metal bond is formed between the first metal structure and the second metal structure, and a dielectric bond is formed between the inorganic layer and the polymer layer.

21. The method for forming the packaging structure as described in claim 20, characterized in that, In the step of providing a first package, the first package includes a first side and a second side facing away from each other, wherein the first side has a first bonding surface and the second side has a second bonding surface. The method of forming the encapsulation structure further includes: providing a second encapsulation body, on which a second bonding surface is formed, the second bonding surface including a polymer layer and a plurality of second metal structures; After providing the second package, the first bonding surface of the first package and the second bonding surface of the second package are bonded together to form a metal bond between the first metal structure and the second metal structure, and a dielectric bond between the inorganic layer and the polymer layer.

22. The method for forming the packaging structure as described in claim 21, characterized in that, In the step of providing the first package, there are multiple first packages, and the multiple first packages are stacked. The first bonding surface in the lower first package is bonded to the second bonding surface in the upper first package.

23. The method for forming the packaging structure as described in claim 22, characterized in that, In the step of providing a device wafer, the device wafer includes a plurality of spaced-apart cell regions, and the first bonding surface is located on the surface of the cell regions; The method for forming the encapsulation structure includes: sequentially bonding a plurality of first encapsulation bodies onto the first bonding surface of each unit region; After bonding multiple first packages in sequence, a second package is bonded to the topmost first package. A molding layer is formed covering the device wafer, the first package, and the second package, with the molding layer exposing the surface of the second package. The molding layer and device wafer are cut along the boundaries of adjacent unit regions to form multiple packaging structures.

24. The method for forming the packaging structure as described in claim 20, characterized in that, The steps of providing the first package include: A first substrate is provided, the first substrate including a first side and a second side opposite to each other, a first metal layer and a metal pillar located below the first metal layer are formed on the first side of the first substrate; A first dielectric stack is formed on a first side of the first substrate, the first dielectric stack comprising: a first dielectric layer, an inorganic layer and a second dielectric layer stacked sequentially; Using the top of the first metal layer as the etching stop position, the first dielectric stack is etched to form a first trench in the first dielectric stack; A conductive material is formed on the surface of the first trench and the first dielectric stack; With the top of the inorganic layer as the planarization stop position, the conductive material layer and the second dielectric layer above the inorganic layer are removed, and the remaining conductive material in the first trench serves as the first metal structure, with the top of the first metal structure recessed. A back-side through-hole exposure process is performed on the second side of the first substrate to expose the metal pillar on the second side; A second metal structure is formed on the metal pillar on the second side of the first substrate; A polymer layer is formed on the second side of the first substrate, covering a portion of the sidewall of the second metal structure, the second metal structure protruding from the polymer layer.

25. The method for forming the packaging structure as described in claim 24, characterized in that, The step of forming a polymer layer covering a portion of the sidewall of the second metal structure on the second side includes: A polymer material layer covering the second metal structure is formed on the second side; The polymer material layer is then cured. Using the top of the second metal structure as the planarization stop position, the cured polymer material layer is planarized to remove the polymer material layer that is higher than the second metal structure. The polymer material layer of a certain thickness is etched to form a polymer layer covering the sidewalls of the second metal structure.

26. The method for forming the packaging structure as described in claim 24, characterized in that, The step of forming a second metal structure on the metal pillar on the second side includes: depositing a second dielectric stack on the second side; etching the second dielectric stack to form a second trench in the second dielectric stack exposing the metal pillar; and forming the second metal structure in the second trench.

27. The method for forming the packaging structure as described in claim 21, characterized in that, The steps of providing the second package include: A second substrate is provided, and a second metal layer is formed on the surface of the second substrate; A second metal structure is formed on the second metal layer; A polymer layer is formed on the second substrate, covering a portion of the sidewall of the second metal structure, the second metal structure protruding from the polymer layer.

28. The method for forming the packaging structure as described in claim 27, characterized in that, The step of forming a second metal structure on the second metal layer includes: A third dielectric layer covering the second metal layer is formed on the second substrate; The third dielectric layer is etched to form a first groove in the third dielectric layer that exposes the second metal layer; A seed layer is formed on the surface of the first groove and the third dielectric layer; After the seed layer is formed, a fourth dielectric layer is formed on the second substrate; The fourth dielectric layer is etched to form a second groove in the fourth dielectric layer; The second metal structure is formed in the second groove.

29. The method for forming the packaging structure as described in claim 27, characterized in that, The step of forming a polymer layer covering a portion of the sidewalls of the second metal structure on the second substrate includes: A polymer material layer covering the second metal structure is formed on the second substrate; The polymer material layer is then cured. Using the top of the second metal structure as the planarization stop position, the cured polymer material layer is planarized to remove the polymer material layer that is higher than the second metal structure. The polymer material layer of a certain thickness is etched to form a polymer layer covering the sidewalls of the second metal structure.

30. The method for forming the packaging structure as described in claim 20, characterized in that, The steps for providing device wafers include: Provide a third base; A metal pillar is formed penetrating the third substrate; A third metal layer is formed on top of the metal pillar; A third dielectric stack is formed covering a third substrate, a metal pillar, and a third metal layer. The third dielectric stack includes a first dielectric layer, an inorganic layer, and a second dielectric layer stacked sequentially. With the top of the third metal layer as the etching stop position, the third dielectric stack is etched to form a first trench in the third dielectric stack. A conductive material is formed on the surfaces of the first trench and the third dielectric stack; Using the top of the inorganic layer as the planarization stop position, the conductive material layer and the second dielectric layer above the inorganic layer are removed, and the remaining conductive material located in the first trench serves as the first metal structure, with the top of the first metal structure recessed.

31. A bonding structure, characterized in that, include: The first bonding surface includes an inorganic layer and a plurality of first metal structures; The second bonding surface is bonded to the first bonding surface, and the second bonding surface includes a polymer layer and a plurality of second metal structures. The first metal structure and the second metal structure form a metallic bond, and the inorganic layer and the polymer layer form a dielectric bond.

32. The bonding structure as described in claim 31, characterized in that, At the interface between the polymer layer and the inorganic layer, the surface of the polymer layer includes carboxyl functional groups, and the surface of the inorganic layer includes hydroxyl dangling bonds, with chemical bonds formed between the carboxyl functional groups and the hydroxyl dangling bonds.

33. The bonding structure as described in claim 31, characterized in that, The first metal structure includes pads, and the second metal structure includes pads.

34. The bonding structure as described in claim 31, characterized in that, Both the first metal structure and the second metal structure adopt <111> Nanotwinned copper with crystalline phase.

35. The bonding structure as described in claim 31, characterized in that, The inorganic layer comprises silicon carbonitride.

36. The bonding structure as described in claim 31, characterized in that, The polymer layer is made of a polymer material with a coefficient of thermal expansion of less than or equal to 50 ppm / K.

37. The bonding structure as described in claim 31, characterized in that, The Young's modulus of the inorganic layer is higher than that of the polymer layer.

38. The bonding structure as described in claim 37, characterized in that, The Young's modulus of the inorganic layer is 70 GPa to 300 GPa, and the Young's modulus of the polymer layer is 0.1 GPa to 3 GPa.

39. The bonding structure as described in claim 31, characterized in that, The polymer layer is made of polyimide.

40. A packaging structure, characterized in that, include: The device package includes a first bonding surface as described in any one of claims 31 to 39, wherein the first bonding surface includes an inorganic layer and a plurality of first metal structures; A first package is bonded to the device package, the first package including a second bonding surface as described in any one of claims 31 to 39, the second bonding surface including a polymer layer and a plurality of second metal structures, the first metal structure and the second metal structures forming a metal bond, and the inorganic layer and the polymer layer forming a dielectric bond.

41. The packaging structure as described in claim 40, characterized in that, The first package includes a first side and a second side facing away from each other, the first side including the first bonding surface, and the second side including the second bonding surface; The encapsulation structure further includes: a second encapsulation body, the second encapsulation body including a second bonding surface, the second bonding surface including a polymer layer and a plurality of second metal structures; The first bonding surface of the first package and the second bonding surface of the second package are bonded together to form a metallic bond between the first metal structure and the second metal structure, and a dielectric bond is formed between the inorganic layer and the polymer layer.

42. The packaging structure as described in claim 41, characterized in that, There are multiple first packages, and the multiple first packages are stacked. The first bonding surface in the lower first package is bonded to the second bonding surface in the upper first package.

43. The packaging structure as described in claim 41, characterized in that, The first package includes: A first substrate, the first substrate including a first side and a second side opposite to each other, the first side of the first substrate having a first metal layer and a metal pillar located below the first metal layer; A first metal structure is located on the first side, on top of the first metal layer; A first dielectric layer is located on the first substrate on the first side of the first metal structure. An inorganic layer is located on the first dielectric layer on the side of the first metal structure, and the inorganic layer and the first dielectric layer completely cover the sidewall of the first metal structure. A second metal structure is located on the second side at the end of the metal pillar away from the first metal layer; A polymer layer is located on the first substrate on the second side of the second metal structure, and the polymer layer covers a portion of the sidewall of the second metal structure.

44. The packaging structure as described in claim 43, characterized in that, The first package also includes: The second dielectric stack is located on the second side between the first substrate and the polymer layer.

45. The packaging structure as described in claim 41, characterized in that, The second package includes: A second substrate, on which a second metal layer is formed; A second metal structure is located on the second metal layer; A polymer layer is located on the second substrate on the side of the second metal structure, and the polymer layer covers a portion of the sidewall of the second metal structure.

46. ​​The packaging structure as described in claim 45, characterized in that, The second package also includes: The third dielectric layer is located between the second substrate and the polymer layer; A seed layer is located between the second metal layer and the second metal structure.

47. The packaging structure as described in claim 41, characterized in that, The device package includes: Third base; A third metal layer is located on top of the third substrate; A metal pillar is located at the bottom of the third metal layer and is connected to the bottom of the third metal layer; a first metal structure is located at the top of the third metal layer; The first dielectric layer is located on the third substrate, the third metal layer, and the metal pillars, and is exposed on the top of the first metal structure; An inorganic layer is located on the first dielectric layer on the side of the first metal structure.

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