Hybrid bonding structure and preparation method thereof

Abstract

The invention relates to the technical field of semiconductor structures, and discloses a hybrid bonding structure and a preparation method thereof, the hybrid bonding structure comprises a first substrate, a first bonding layer, a second bonding layer and a second substrate; the first bonding layer comprises a plurality of first metal layer units arranged at intervals and first dielectric layers at the side parts of the first metal layer units; a first dielectric layer groove is formed in the surface of one side, opposite to the first substrate, of the first dielectric layer; the first dielectric layer grooves are located between the adjacent first metal layer units and located at the pre-cutting line position of the hybrid bonding structure; each mixed bonding structure unit at least comprises a first metal layer unit; the second bonding layer comprises a plurality of second metal layer units arranged at intervals and second dielectric layers on the side parts of the second metal layer units; and the first bonding layer and the second bonding layer are connected into an integrated structure through hybrid bonding. Compared with the prior art, the thermal reliability, stability and reliability of the hybrid bonding structure can be improved, and the hybrid bonding yield is further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor structures, and in particular to a hybrid bonding structure and a preparation method thereof. Background Art

[0002] Three-dimensional integration technology is an important direction for achieving continuous improvement in chip performance. Chip hybrid bonding technology is a key technology for achieving three-dimensional chip stacking, and plays an important role in technologies such as Chiplet, HBM, and CIS. The current hybrid bonding process requires strict control of contaminants (e.g., particles). During the semiconductor packaging process, the substrate slicing process will produce particles, such as silicon debris, and tiny hard particles (the particle size is generally less than 500nm or lower) will be produced on the surface of the dielectric layer at the hybrid bonding interface. According to research, particles with a size of 1μm can cause a bonding gap of 10mm, resulting in bonding defects. The current standard cleaning operation can only remove particles larger than 1μm, while particles smaller than 1μm cannot be removed by standard cleaning operations, and will remain on the semiconductor substrate and the surface of the dielectric layer, and are very likely to appear at the hybrid bonding interface, resulting in bonding gaps inside the hybrid bonding structure, and ultimately leading to the failure of hybrid bonding.

[0003] One solution in the related art is to set a dielectric cavity around the metal bump of the hybrid bonding interface to accommodate the particles on the two opposite surfaces of the hybrid bonding interface. However, in this solution, due to the cavity around the metal bump, the metal bump is very easy to expand to the left and right during the annealing stage, and the expansion in the vertical direction is limited, which is prone to bonding voids. In addition, the pure cavity structure will lead to low thermal reliability of the hybrid bonding structure. When heated, the air in the cavity expands, and the bonding interface is easily cracked, causing chip failure. Summary of the invention

[0004] In view of this, the present invention provides a hybrid bonding structure and a preparation method thereof to solve the problems in the related art that tiny hard particles exist on the surface of the dielectric layer at the hybrid bonding interface, resulting in bonding gaps inside the hybrid bonding structure, and cavities exist inside the hybrid bonding structure, resulting in bonding voids inside the hybrid bonding structure and low thermal reliability.

[0005] In a first aspect, the present invention provides a hybrid bonding structure, comprising:

[0006] a first substrate;

[0007] A first bonding layer is located on a surface of one side of the first substrate; the first bonding layer includes a plurality of first metal layer units arranged at intervals and a first dielectric layer on a side of the first metal layer unit; the first dielectric layer has a first dielectric layer groove on a surface of a side facing away from the first substrate; the first dielectric layer groove is located between adjacent first metal layer units and at a pre-cutting line position of the hybrid bonding structure; the pre-cutting line position divides the hybrid bonding structure into a plurality of hybrid bonding structure units; each hybrid bonding structure unit includes at least one first metal layer unit;

[0008] The second bonding layer is located on the surface of the first bonding layer facing away from the first substrate; the second bonding layer comprises a plurality of second metal layer units arranged at intervals and a second dielectric layer on the side of the second metal layer unit;

[0009] The first bonding layer and the second bonding layer are connected to form an integrated structure through hybrid bonding; wherein the first dielectric layer and the second dielectric layer are in corresponding contact and bonded together, and the first metal layer unit and the second metal layer unit are in one-to-one corresponding contact and bonded together;

[0010] The second substrate is located on a surface of the second bonding layer that is away from the first bonding layer.

[0011] The hybrid bonding structure provided by the present invention, on the one hand, can accommodate tiny particles on the surfaces of the first dielectric layer and the second dielectric layer by setting a first dielectric layer groove on the surface of the side facing away from the first substrate, reduce the influence of the particles on the bonding interface, prevent the hybrid bonding structure from having void defects at the bonding interface, increase the particle tolerance of the hybrid bonding interface, and improve the stability and reliability of the hybrid bonding structure; on the other hand, the first dielectric layer groove is located between adjacent first metal layer units and at the pre-cutting line position of the hybrid bonding structure, which is equivalent to reserving a void position outside the hybrid bonding structure unit (i.e., a unit including the bonded metal layer and the side dielectric layer) formed after cutting, so that the interior of the hybrid bonding structure unit formed after cutting is free of voids, improve the thermal reliability of the hybrid bonding structure unit formed after cutting, prevent the generation of bonding voids, and avoid the hybrid bonding structure unit formed after cutting from being thermally expanded and cracked, thereby improving the stability and reliability of the hybrid bonding structure unit formed after cutting. Therefore, the hybrid bonding structure provided by the present invention can increase the particle tolerance of the hybrid bonding interface, make the interior of the hybrid bonding structure free of voids, improve the stability and reliability of the hybrid bonding structure, and thus improve the hybrid bonding yield; at the same time, it further makes the interior of the hybrid bonding unit formed after cutting free of voids, improves the thermal reliability of the hybrid bonding structure unit formed after cutting, thereby improving the stability and reliability of the hybrid bonding structure unit formed after cutting.

[0012] In an optional implementation, a second dielectric layer groove is provided on a surface of the second dielectric layer facing away from the second substrate; the second dielectric layer groove is located between adjacent second metal layer units and at a pre-cutting line position of the hybrid bonding structure.

[0013] The hybrid bonding structure provided by the present invention is characterized in that a second dielectric layer groove is arranged on a surface of the second dielectric layer on the side facing away from the second substrate; the second dielectric layer groove is located between adjacent second metal layer units and at a pre-cutting line position of the hybrid bonding structure, and can accommodate tiny particles on the surface of the first dielectric layer and the second dielectric layer, further increasing the particle tolerance of the hybrid bonding interface, making the interior of the hybrid bonding structure free of voids, improving the stability and reliability of the hybrid bonding structure, and further improving the hybrid bonding yield; at the same time, it further makes the interior of the hybrid bonding unit formed after cutting free of voids, improves the thermal reliability of the hybrid bonding structure unit formed after cutting, and thus improves the stability and reliability of the hybrid bonding structure unit formed after cutting.

[0014] In an optional embodiment, the positions of the first dielectric layer grooves correspond vertically to the positions of the second dielectric layer grooves, and the same group of first dielectric layer grooves and second dielectric layer grooves that correspond in position are located at the same pre-cutting line position.

[0015] The hybrid bonding structure provided by the present invention sets the position of the first dielectric layer groove and the position of the second dielectric layer groove to correspond vertically, and the same group of first dielectric layer grooves and second dielectric layer grooves with corresponding positions are located at the same pre-cutting line position, so that the first dielectric layer grooves and the second dielectric layer grooves can be vertically corresponding and connected to form larger grooves, which is conducive to better accommodating tiny particles on the surfaces of the first dielectric layer and the second dielectric layer, further increasing the particle tolerance of the hybrid bonding interface, improving the stability and reliability of the hybrid bonding structure, and thus improving the hybrid bonding yield. At the same time, the thermal reliability of the hybrid bonding structure unit formed after cutting can be improved, thereby improving the stability and reliability of the hybrid bonding structure unit formed after cutting.

[0016] In an optional implementation, the position of the first dielectric layer groove does not correspond to the position of the second dielectric layer groove, and the first dielectric layer groove and the second dielectric layer groove are respectively located at different pre-cutting line positions.

[0017] The hybrid bonding structure provided by the present invention can provide a dielectric layer groove at each pre-cutting line position as much as possible by arranging the position of the first dielectric layer groove and the position of the second dielectric layer groove not to correspond to each other, and the first dielectric layer groove and the second dielectric layer groove are respectively located at different pre-cutting line positions, so as to accommodate particles at different positions or regions on the surface of the first dielectric layer and the surface of the second dielectric layer as much as possible, further increase the particle tolerance of the hybrid bonding interface, improve the stability and reliability of the hybrid bonding structure, and thus improve the hybrid bonding yield, and at the same time, can improve the thermal reliability of the hybrid bonding structure unit formed after cutting, thereby improving the stability and reliability of the hybrid bonding structure unit formed after cutting, and can also simplify the process flow and improve the process efficiency.

[0018] In an optional implementation, the pre-cutting line position corresponding to the groove of the first dielectric layer further has a first through hole; the first through hole penetrates the first substrate and the first dielectric layer and extends into the groove of the first dielectric layer.

[0019] The hybrid bonding structure provided by the present invention is provided with a first through hole at a pre-cutting line position corresponding to a groove of the first dielectric layer. The first through hole penetrates the first substrate and the first dielectric layer and extends into the groove of the first dielectric layer. The first through hole can play a role of exhaust, and various gaseous by-products generated during the annealing process can be discharged in time, so as to reduce the influence on the hybrid structure and improve the reliability of the hybrid bonding structure. At the same time, the first through hole is located at the pre-cutting line position of the hybrid bonding structure, so that there is no gap inside the hybrid bonding structure unit formed after cutting, so as to improve the thermal reliability of the hybrid bonding structure unit formed after cutting, prevent the generation of bonding voids, and avoid the hybrid bonding structure unit formed after cutting from being thermally expanded and cracked, thereby improving the stability and reliability of the hybrid bonding structure unit formed after cutting.

[0020] In an optional implementation, the pre-cutting line position corresponding to the groove of the second dielectric layer further has a second through hole; the second through hole penetrates the second substrate and the second dielectric layer and extends into the groove of the second dielectric layer.

[0021] The hybrid bonding structure provided by the present invention is provided with a second through hole at a pre-cutting line position corresponding to the groove of the second dielectric layer. The second through hole penetrates the second substrate and the second dielectric layer and extends into the groove of the second dielectric layer. The second through hole can play a role of exhaust, and various gaseous by-products generated during the annealing process can be discharged in time, thereby reducing the impact on the hybrid bonding structure and improving the reliability of the hybrid bonding structure. At the same time, the second through hole is located at the pre-cutting line position of the hybrid bonding structure, so that there is no gap inside the hybrid bonding structure unit formed after cutting, thereby improving the thermal reliability of the hybrid bonding structure unit formed after cutting, preventing the generation of bonding voids, and avoiding the hybrid bonding structure unit formed after cutting from being thermally expanded and cracked, thereby improving the stability and reliability of the hybrid bonding structure unit formed after cutting.

[0022] In an optional embodiment, the material of the first dielectric layer is SiO2, SiCN or SiN; the material of the second dielectric layer is SiO2, SiCN or SiN;

[0023] The diameter or width of the groove of the first dielectric layer is less than 50 μm to 100 μm; the depth of the groove of the first dielectric layer is 2 μm to 5 μm;

[0024] The diameter or width of the groove of the second dielectric layer is less than 50 μm to 100 μm; the depth of the groove of the second dielectric layer is 2 μm to 5 μm;

[0025] The diameter of the first through hole is less than 50 μm;

[0026] The diameter of the second through hole is less than 50 μm.

[0027] In a second aspect, the present invention provides a method for preparing a hybrid bonding structure, which is used to prepare the hybrid bonding structure of the first aspect, and the preparation method comprises:

[0028] providing a first substrate;

[0029] A first bonding layer is formed on a surface of one side of the first substrate, wherein the first bonding layer includes a plurality of first metal layer units arranged at intervals and a first dielectric layer on a side of the first metal layer unit;

[0030] A first dielectric layer groove is formed on a surface of the first dielectric layer facing away from the first substrate; the first dielectric layer groove is located between adjacent first metal layer units and at a pre-cutting line position of the hybrid bonding structure; the pre-cutting line position divides the hybrid bonding structure into a plurality of hybrid bonding structure units; each hybrid bonding structure unit includes at least one first metal layer unit;

[0031] providing a second substrate;

[0032] A second bonding layer is formed on a surface of one side of the second substrate, wherein the second bonding layer comprises a plurality of second metal layer units arranged at intervals and a first dielectric layer at a side of the second metal layer unit;

[0033] The first substrate and the second substrate are hybrid bonded together to form a hybrid bonding structure; the first bonding layer and the second bonding layer are connected into an integrated structure through hybrid bonding; wherein the first dielectric layer and the second dielectric layer are correspondingly contacted and bonded together, and the first metal layer unit and the second metal layer unit are correspondingly contacted and bonded together.

[0034] The preparation method of the hybrid bonding structure provided by the present invention, on the one hand, by forming a first dielectric layer groove on the side surface of the first dielectric layer facing away from the first substrate, tiny particles on the surfaces of the first dielectric layer and the second dielectric layer can be accommodated, the influence of the particles on the bonding interface is reduced, the hybrid bonding structure is prevented from having void defects at the bonding interface, the particle tolerance of the hybrid bonding interface is increased, and the stability and reliability of the hybrid bonding structure are improved; on the other hand, the first dielectric layer groove is located between adjacent first metal layer units and at the pre-cutting line position of the hybrid bonding structure, which is equivalent to reserving the void position outside the hybrid bonding structure unit (i.e., the unit including the bonded metal layer and the side dielectric layer) formed after cutting, so that the interior of the hybrid bonding structure unit formed after cutting is free of voids, the thermal reliability of the hybrid bonding structure unit formed after cutting is improved, the generation of bonding voids is prevented, and the hybrid bonding structure unit formed after cutting is avoided from being thermally expanded and cracked, thereby improving the stability and reliability of the hybrid bonding structure unit formed after cutting. Therefore, the hybrid bonding structure provided by the present invention can increase the particle tolerance of the hybrid bonding interface, make the interior of the hybrid bonding structure free of voids, improve the stability and reliability of the hybrid bonding structure, and thus improve the hybrid bonding yield; at the same time, it further makes the interior of the hybrid bonding unit formed after cutting free of voids, improves the thermal reliability of the hybrid bonding structure unit formed after cutting, thereby improving the stability and reliability of the hybrid bonding structure unit formed after cutting.

[0035] In an optional implementation manner, before the step of hybrid bonding the first substrate and the second substrate together, the step further includes:

[0036] A second dielectric layer groove is formed on a surface of the second dielectric layer facing away from the second substrate; the second dielectric layer groove is located between adjacent second metal layer units and at a pre-cutting position of the hybrid bonding structure.

[0037] In an optional embodiment, after the step of forming a first dielectric layer groove on a surface of the first dielectric layer facing away from the first substrate, the step includes: forming a first through hole at a position of the pre-cutting line corresponding to the first dielectric layer groove; the first through hole penetrates the first substrate and the first dielectric layer and extends into the first dielectric layer groove;

[0038] and / or:

[0039] After forming a second dielectric layer groove on the surface of the second dielectric layer facing away from the second substrate, the method includes forming a second through hole at the pre-cutting line position corresponding to the second dielectric layer groove; the second through hole penetrates the second substrate and the second dielectric layer and extends into the second dielectric layer groove. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the related technologies, the drawings required for use in the specific embodiments or the related technical descriptions will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0041] Figure 1 It is a schematic diagram of a bonding structure in the related art.

[0042] Figure 2 is a structural schematic diagram of a hybrid bonding structure according to an embodiment of the present invention.

[0043] Figure 3 is a top view of a hybrid bonding structure according to an embodiment of the present invention.

[0044] Figure 4 is a schematic structural diagram of another hybrid bonding structure according to an embodiment of the present invention.

[0045] Figure 5 It is a schematic flow chart of a method for preparing a hybrid bonding structure according to an embodiment of the present invention.

[0046] Figure 6 It is a schematic diagram of a hybrid bonding structure for forming a first dielectric layer groove in a method for preparing a hybrid bonding structure according to an embodiment of the present invention.

[0047] Figure 7 Schematic diagram of a hybrid bonding structure for forming a second dielectric layer groove in a method for preparing a hybrid bonding structure according to an embodiment of the present invention.

[0048] Figure 8 In a method for preparing a hybrid bonding structure according to an embodiment of the present invention, Figure 6 and Figure 7 Schematic diagram of the structure of hybrid bonding of the first substrate and the second substrate.

[0049] Fig. 9 It is a schematic diagram of a hybrid bonding structure for forming a first dielectric layer groove in a method for preparing a hybrid bonding structure according to an embodiment of the present invention.

[0050] Fig.10 Schematic diagram of a hybrid bonding structure for forming a second dielectric layer groove in a method for preparing a hybrid bonding structure according to an embodiment of the present invention.

[0051] Fig.11 In a method for preparing a hybrid bonding structure according to an embodiment of the present invention, Fig. 9 and Fig.10Schematic diagram of the structure of hybrid bonding of the first substrate and the second substrate.

[0052] Fig.12 It is a specific schematic diagram of a method for preparing a hybrid bonding structure according to an embodiment of the present invention.

[0053] Fig.13 It is a specific schematic diagram of a method for preparing another hybrid bonding structure according to an embodiment of the present invention.

[0054] Reference numerals:

[0055] 1. Substrate; 2. Dielectric layer; 3. Metal bump; 4. Dielectric cavity; 11. First substrate; 12. First bonding layer; 121. First metal layer unit; 122. First dielectric layer; 13. First dielectric layer groove; 14. First through hole; 21. Second substrate; 22. Second bonding layer; 221. Second metal layer unit; 222. Second dielectric layer; 23. Second dielectric layer groove; 24. Second through hole; 30. Pre-cut line. DETAILED DESCRIPTION

[0056] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0057] In the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention. Various structural schematic diagrams according to embodiments of the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified for the purpose of clear expression, and some details may be omitted. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships between them are only exemplary, and may be deviated due to manufacturing tolerances or technical limitations in practice, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs. In the context of the present invention, when a layer / element is referred to as being "on" another layer / element, the layer / element may be directly on the other layer / element, or there may be a middle layer / element between them. In addition, if a layer / element is "on" another layer / element in one orientation, then when the orientation is reversed, the layer / element may be "under" the other layer / element.

[0058] Three-dimensional integration technology is an important direction for achieving continuous improvement in chip performance. Chip hybrid bonding technology is a key technology for achieving three-dimensional chip stacking, and plays an important role in technologies such as Chiplet, HBM, and CIS. The current hybrid bonding process requires strict control of contaminants (e.g., particles). During the semiconductor packaging process, the substrate slicing process will produce particles, such as silicon debris, and tiny hard particles (the particle size is generally less than 500nm or lower) will be produced on the surface of the dielectric layer at the hybrid bonding interface. According to research, particles with a size of 1μm can cause a bonding gap of 10mm, resulting in bonding defects. The current standard cleaning operation can only remove particles larger than 1μm, while particles smaller than 1μm cannot be removed by standard cleaning operations, and will remain on the semiconductor substrate and the surface of the dielectric layer, and are very likely to appear at the hybrid bonding interface, resulting in bonding gaps inside the hybrid bonding structure, and ultimately leading to the failure of hybrid bonding.

[0059] A solution in the related art is as follows Figure 1 As shown in FIG. 1 , the hybrid bonding structure is formed by bonding two identical parts, the upper and lower parts; in the formed bonding structure, the dielectric layer 2 and the metal bump 3 are located on the substrate 1, and the particles on the opposite surfaces of the upper and lower parts are accommodated by setting a dielectric cavity 4 around the metal bump 3 at the hybrid bonding interface. However, in this scheme, due to the cavity around the metal bump 3, the metal bump is very easy to expand to the left and right during the annealing stage, and the expansion in the vertical direction is limited, which is easy to cause bonding. Figure 1 The void situation shown, that is, the metal bumps 3 of the upper and lower parts are not bonded as expected, but a disconnected gap appears; in addition, the pure cavity structure will lead to low thermal reliability of the hybrid bonding structure. When heated, the air in the cavity expands, and the bonding interface is easily cracked, causing chip failure.

[0060] like Figure 2 As shown, this embodiment provides a hybrid bonding structure, and the hybrid bonding structure includes:

[0061] A first substrate 11;

[0062] The first bonding layer 12 is located on one side surface of the first substrate 11; the first bonding layer 12 includes a plurality of first metal layer units 121 arranged at intervals and a first dielectric layer 122 on the side of the first metal layer unit 121; the first dielectric layer 122 has a first dielectric layer groove 13 on the side surface facing away from the first substrate 11; the first dielectric layer groove 13 is located between adjacent first metal layer units 121 and at the position of the pre-cutting line 30 of the hybrid bonding structure; the position of the pre-cutting line 30 divides the hybrid bonding structure into a plurality of hybrid bonding structure units; each hybrid bonding structure unit includes at least one first metal layer unit 121;

[0063] The second bonding layer 22 is located on the surface of the first bonding layer 12 facing away from the first substrate 11; the second bonding layer 22 includes a plurality of second metal layer units 221 arranged at intervals and a second dielectric layer 222 on the side of the second metal layer unit 221;

[0064] The first bonding layer 12 and the second bonding layer 22 are connected to form an integrated structure through hybrid bonding; wherein the first dielectric layer 122 and the second dielectric layer 222 are in corresponding contact and bonded together, and the first metal layer unit 121 and the second metal layer unit 221 are in one-to-one corresponding contact and bonded together;

[0065] The second substrate 21 is located on a surface of the second bonding layer 22 that is away from the first bonding layer 12 .

[0066] In a specific implementation, the materials of the first substrate 11 and the second substrate 21 can be silicon (Si), silicon on insulator (SOI), silicon carbide (SiC), silicon germanium (SiGe), etc. The first dielectric layer groove 13 is suitable for accommodating tiny particles on the surface of the first dielectric layer 122 and the second dielectric layer 222. During the bonding process of the first bonding layer 12 and the second bonding layer 22, the tiny particles on the surface of the first dielectric layer 122 and the second dielectric layer 222 enter the nearby first dielectric layer groove 13 along with the diffusion of the bonding wave.

[0067] Specifically, in some specific embodiments, the top view of the hybrid bonding structure is as follows Figure 3 As shown, based on the hybrid bonding structure, the hybrid bonding structure can be divided into a plurality of hybrid bonding structure units along the pre-cutting line 30 according to requirements; each hybrid bonding structure unit includes at least one first metal layer unit 121 .

[0068] The hybrid bonding structure provided in this embodiment, on the one hand, by setting a first dielectric layer groove on the surface of the first dielectric layer on the side facing away from the first substrate, can accommodate tiny particles on the surfaces of the first dielectric layer and the second dielectric layer, reduce the influence of the particles on the bonding interface, prevent the hybrid bonding structure from having void defects at the bonding interface, increase the particle tolerance of the hybrid bonding interface, and improve the stability and reliability of the hybrid bonding structure; on the other hand, the first dielectric layer groove is located between adjacent first metal layer units and at the pre-cutting line position of the hybrid bonding structure, which is equivalent to reserving a void position outside the hybrid bonding structure unit (i.e., a unit including the bonded metal layer and the side dielectric layer) formed after cutting, so that the interior of the hybrid bonding structure unit formed after cutting is free of voids, improve the thermal reliability of the hybrid bonding structure unit formed after cutting, prevent the generation of bonding voids, and avoid the hybrid bonding structure unit formed after cutting from being thermally expanded and cracked, thereby improving the stability and reliability of the hybrid bonding structure unit formed after cutting. Therefore, the hybrid bonding structure provided by the present invention can increase the particle tolerance of the hybrid bonding interface, make the interior of the hybrid bonding structure free of voids, improve the stability and reliability of the hybrid bonding structure, and thus improve the hybrid bonding yield; at the same time, it further makes the interior of the hybrid bonding unit formed after cutting free of voids, improves the thermal reliability of the hybrid bonding structure unit formed after cutting, thereby improving the stability and reliability of the hybrid bonding structure unit formed after cutting.

[0069] In some optional embodiments, such as Figure 2 As shown, the second dielectric layer 222 has a second dielectric layer groove 23 on one side of the surface facing away from the second substrate 21 ; the second dielectric layer groove 23 is located between adjacent second metal layer units 221 and at the position of the pre-cutting line 30 of the hybrid bonding structure.

[0070] The hybrid bonding structure provided in the present embodiment has a second dielectric layer groove on the surface of the second dielectric layer facing away from the second substrate; the second dielectric layer groove is located between adjacent second metal layer units and at the pre-cutting line position of the hybrid bonding structure, and can accommodate tiny particles on the surface of the first dielectric layer and the second dielectric layer, further increasing the particle tolerance of the hybrid bonding interface, making the interior of the hybrid bonding structure free of voids, improving the stability and reliability of the hybrid bonding structure, and further improving the hybrid bonding yield; at the same time, it further makes the interior of the hybrid bonding unit formed after cutting free of voids, improves the thermal reliability of the hybrid bonding structure unit formed after cutting, thereby improving the stability and reliability of the hybrid bonding structure unit formed after cutting.

[0071] In some optional embodiments, the positions of the first dielectric layer grooves 13 and the positions of the second dielectric layer grooves 23 correspond vertically, and the same group of first dielectric layer grooves 13 and second dielectric layer grooves 23 with corresponding positions are located at the same pre-cutting line.

[0072] The hybrid bonding structure provided in the present embodiment sets the position of the first dielectric layer groove and the position of the second dielectric layer groove to correspond vertically, and the same group of first dielectric layer grooves and second dielectric layer grooves with corresponding positions are located at the same pre-cutting line position, so that the first dielectric layer grooves and the second dielectric layer grooves can be vertically aligned and connected to form larger grooves, which is conducive to better accommodating tiny particles on the surfaces of the first dielectric layer and the second dielectric layer, further increasing the particle tolerance of the hybrid bonding interface, improving the stability and reliability of the hybrid bonding structure, and thus improving the hybrid bonding yield. At the same time, the thermal reliability of the hybrid bonding structure unit formed after cutting can be improved, thereby improving the stability and reliability of the hybrid bonding structure unit formed after cutting.

[0073] In some optional implementations, the position of the first dielectric layer groove 13 does not correspond to the position of the second dielectric layer groove 23 , and the first dielectric layer groove 13 and the second dielectric layer groove 23 are respectively located at different pre-cutting lines 30 .

[0074] The hybrid bonding structure provided in the present embodiment, by setting the position of the first dielectric layer groove and the position of the second dielectric layer groove not to correspond, and the first dielectric layer groove and the second dielectric layer groove are respectively located at different pre-cutting line positions, so that each pre-cutting line position can have a dielectric layer groove as much as possible, and particles at different positions or regions on the surface of the first dielectric layer and the surface of the second dielectric layer can be accommodated as much as possible, further increasing the particle tolerance of the hybrid bonding interface, improving the stability and reliability of the hybrid bonding structure, and thus improving the hybrid bonding yield, and at the same time, can improve the thermal reliability of the hybrid bonding structure unit formed after cutting, thereby improving the stability and reliability of the hybrid bonding structure unit formed after cutting, and can also simplify the process flow and improve the process efficiency.

[0075] In some optional embodiments, such as Figure 4 As shown, the first dielectric layer groove 13 also has a first through hole 14 at the position of the pre-cutting line 30 corresponding to the first dielectric layer groove 13 ; the first through hole 14 penetrates the first substrate 11 and the first dielectric layer 122 , and extends into the first dielectric layer groove 13 .

[0076] The hybrid bonding structure provided in the present embodiment is provided with a first through hole at the pre-cutting line position corresponding to the groove of the first dielectric layer. The first through hole penetrates the first substrate and the first dielectric layer and extends into the groove of the first dielectric layer. The first through hole can play the role of exhaust, and various gaseous by-products generated during the annealing process can be discharged in time, so as to reduce the influence on the hybrid structure and improve the reliability of the hybrid bonding structure. At the same time, the first through hole is located at the pre-cutting line position of the hybrid bonding structure, so that there is no gap inside the hybrid bonding structure unit formed after cutting, so as to improve the thermal reliability of the hybrid bonding structure unit formed after cutting, prevent the generation of bonding voids, and avoid the hybrid bonding structure unit formed after cutting from being cracked due to heat, thereby improving the stability and reliability of the hybrid bonding structure unit formed after cutting.

[0077] In some optional embodiments, such as Figure 4 As shown, the second dielectric layer groove 23 further has a second through hole 24 at the position of the pre-cutting line 30 corresponding to the second dielectric layer groove 23 ; the second through hole 24 penetrates the second substrate 21 and the second dielectric layer 222 , and extends into the second dielectric layer groove 23 .

[0078] The hybrid bonding structure provided in the present embodiment is provided with a second through hole at the pre-cutting line position corresponding to the groove of the second dielectric layer. The second through hole penetrates the second substrate and the second dielectric layer and extends into the groove of the second dielectric layer. The second through hole can play the role of exhaust, and various gaseous by-products generated during the annealing process can be discharged in time, thereby reducing the impact on the hybrid bonding structure and improving the reliability of the hybrid bonding structure. At the same time, the second through hole is located at the pre-cutting line position of the hybrid bonding structure, so that there is no gap inside the hybrid bonding structure unit formed after cutting, thereby improving the thermal reliability of the hybrid bonding structure unit formed after cutting, preventing the generation of bonding voids, and avoiding the hybrid bonding structure unit formed after cutting from being thermally expanded and cracked, thereby improving the stability and reliability of the hybrid bonding structure unit formed after cutting.

[0079] In some optional embodiments, the material of the first dielectric layer 122 is SiO2, SiCN or SiN; the material of the second dielectric layer 222 is SiO2, SiCN or SiN;

[0080] The diameter or width of the first dielectric layer groove 13 is less than 50 μm to 100 μm, such as 50 μm, 70 μm, 80 μm, 90 μm or 100 μm; the depth of the first dielectric layer groove 13 is 2 μm to 5 μm, such as 2 μm, 3 μm, 4 μm or 5 μm;

[0081] The diameter or width of the second dielectric layer groove 23 is less than 50 μm to 100 μm, such as 50 μm, 70 μm, 80 μm, 90 μm or 100 μm; the depth of the second dielectric layer groove 23 is 2 μm to 5 μm, such as 2 μm, 3 μm, 4 μm or 5 μm;

[0082] The diameter of the first through hole 14 is less than 50 μm, for example, 10 μm, 20 μm, 30 μm or 40 μm;

[0083] The diameter of the second through hole 24 is smaller than 50 μm, for example, 10 μm, 20 μm, 30 μm or 40 μm.

[0084] like Figure 5 As shown, this embodiment provides a method for preparing a hybrid bonding structure, and the preparation method includes but is not limited to steps S101 to S106.

[0085] Step S101, providing a first substrate;

[0086] Step S102, forming a first bonding layer on a surface of one side of the first substrate, the first bonding layer comprising a plurality of first metal layer units arranged at intervals and a first dielectric layer on the side of the first metal layer unit;

[0087] Step S103, forming a first dielectric layer groove on a surface of the first dielectric layer facing away from the first substrate, such as Figure 6 As shown; the first dielectric layer groove is located between adjacent first metal layer units and at the pre-cutting line position of the hybrid bonding structure; the pre-cutting line position divides the hybrid bonding structure into a plurality of hybrid bonding structure units; each hybrid bonding structure unit includes at least one first metal layer unit;

[0088] Step S104, providing a second substrate;

[0089] Step S105, forming a second bonding layer on a surface of one side of the second substrate, the second bonding layer comprising a plurality of second metal layer units arranged at intervals and a second dielectric layer on the side of the second metal layer unit;

[0090] Step S106, hybrid bonding the first substrate and the second substrate together to form a hybrid bonding structure, such as Figure 8 As shown; the first bonding layer and the second bonding layer are connected to form an integrated structure through hybrid bonding; wherein the first dielectric layer and the second dielectric layer are in corresponding contact and bonded together, and the first metal layer unit and the second metal layer unit are in one-to-one corresponding contact and bonded together.

[0091] In specific implementation, the first dielectric layer groove is formed on the surface of the first dielectric layer facing away from the first substrate by etching, punching, cutting or other grooving processes. The specific method can be selected according to actual conditions and is not limited in this embodiment.

[0092] The preparation method of the hybrid bonding structure provided in the present embodiment, on the one hand, by forming a first dielectric layer groove on the side surface of the first dielectric layer facing away from the first substrate, tiny particles on the surfaces of the first dielectric layer and the second dielectric layer can be accommodated, the influence of the particles on the bonding interface is reduced, the hybrid bonding structure is prevented from having void defects at the bonding interface, the particle tolerance of the hybrid bonding interface is increased, and the stability and reliability of the hybrid bonding structure are improved; on the other hand, the first dielectric layer groove is located between adjacent first metal layer units and at the pre-cutting line position of the hybrid bonding structure, which is equivalent to reserving the void position outside the hybrid bonding structure unit (i.e., the unit including the bonded metal layer and the side dielectric layer) formed after cutting, so that the interior of the hybrid bonding structure unit formed after cutting is free of voids, the thermal reliability of the hybrid bonding structure unit formed after cutting is improved, the generation of bonding voids is prevented, and the hybrid bonding structure unit formed after cutting is prevented from being thermally expanded and cracked, thereby improving the stability and reliability of the hybrid bonding structure unit formed after cutting. Therefore, the hybrid bonding structure provided by the present invention can increase the particle tolerance of the hybrid bonding interface, make the interior of the hybrid bonding structure free of voids, improve the stability and reliability of the hybrid bonding structure, and thus improve the hybrid bonding yield; at the same time, it further makes the interior of the hybrid bonding unit formed after cutting free of voids, improves the thermal reliability of the hybrid bonding structure unit formed after cutting, thereby improving the stability and reliability of the hybrid bonding structure unit formed after cutting.

[0093] In an optional embodiment, if Figure 7 As shown, before the step of hybrid bonding the first substrate and the second substrate together, the step further includes:

[0094] A second dielectric layer groove is formed on a surface of the second dielectric layer facing away from the second substrate; the second dielectric layer groove is located between adjacent second metal layer units and at a pre-cutting position of the hybrid bonding structure.

[0095] The hybrid bonding structure provided in the present embodiment forms a second dielectric layer groove on the surface of the second dielectric layer facing away from the second substrate; the second dielectric layer groove is located between adjacent second metal layer units and at the pre-cutting line position of the hybrid bonding structure, and can accommodate tiny particles on the surface of the first dielectric layer and the second dielectric layer, further increasing the particle tolerance of the hybrid bonding interface, making the interior of the hybrid bonding structure free of voids, improving the stability and reliability of the hybrid bonding structure, and further improving the hybrid bonding yield; at the same time, it further makes the interior of the hybrid bonding unit formed after cutting free of voids, improves the thermal reliability of the hybrid bonding structure unit formed after cutting, thereby improving the stability and reliability of the hybrid bonding structure unit formed after cutting.

[0096] In an optional embodiment, if Fig. 9As shown, after the step of forming a first dielectric layer groove on a surface of the first dielectric layer facing away from the first substrate, the method further comprises: forming a first through hole at a position of a pre-cutting line corresponding to the first dielectric layer groove; the first through hole penetrates the first substrate and the first dielectric layer, and extends into the first dielectric layer groove;

[0097] and / or:

[0098] like Fig.10 As shown, after the step of forming a second dielectric layer groove on the surface of the second dielectric layer facing away from the second substrate, the method includes: forming a second through hole at the pre-cutting line position corresponding to the second dielectric layer groove; the second through hole penetrates the second substrate and the second dielectric layer, and extends into the second dielectric layer groove.

[0099] The hybrid bonding structure provided in the present embodiment can play a role in exhaust by setting the first through hole and / or the second through hole, and can timely exhaust various gaseous by-products generated in the annealing process, reduce the impact on the hybrid structure, and improve the reliability of the hybrid bonding structure; at the same time, the first through hole and / or the second through hole are located at the pre-cutting line position of the hybrid bonding structure, so that the interior of the hybrid bonding structure unit formed after cutting is free of gaps, thereby improving the thermal reliability of the hybrid bonding structure unit formed after cutting, preventing the generation of bonding voids, and avoiding the hybrid bonding structure unit formed after cutting from being cracked due to heat, thereby improving the stability and reliability of the hybrid bonding structure unit formed after cutting.

[0100] like Fig.12 The present invention also provides a specific flow chart of a method for preparing a hybrid bonding structure, comprising the following steps:

[0101] Step S201, providing a first substrate;

[0102] Step S202, forming a first bonding layer on a surface of one side of the first substrate, the first bonding layer comprising a plurality of first metal layer units arranged at intervals and a first dielectric layer on the side of the first metal layer unit;

[0103] Step S203, forming a first dielectric layer groove on a surface of the first dielectric layer facing away from the first substrate, such as Figure 6 As shown; the first dielectric layer groove is located between adjacent first metal layer units and at the pre-cutting line position of the hybrid bonding structure; the pre-cutting line position divides the hybrid bonding structure into a plurality of hybrid bonding structure units; each hybrid bonding structure unit includes at least one first metal layer unit;

[0104] Step S204, providing a second substrate;

[0105] Step S205, forming a second bonding layer on a surface of one side of the second substrate, the second bonding layer comprising a plurality of second metal layer units arranged at intervals and a second dielectric layer on the side of the second metal layer unit;

[0106] Step S206, forming a second dielectric layer groove on a surface of the second dielectric layer facing away from the second substrate, such as Figure 7 As shown; the second dielectric layer groove is located between adjacent second metal layer units and at a pre-cutting position of the hybrid bonding structure;

[0107] Step S207, hybrid bonding the first substrate and the second substrate together to form a hybrid bonding structure, such as Figure 8 As shown; the first bonding layer and the second bonding layer are connected to form an integrated structure through hybrid bonding; wherein the first dielectric layer and the second dielectric layer are in corresponding contact and bonded together, and the first metal layer unit and the second metal layer unit are in one-to-one corresponding contact and bonded together.

[0108] like Fig.13 As shown, the present invention also provides a specific flow diagram of another method for preparing a hybrid bonding structure, comprising the following steps:

[0109] Step S301, providing a first substrate;

[0110] Step S302, forming a first bonding layer on a surface of one side of the first substrate, the first bonding layer comprising a plurality of first metal layer units arranged at intervals and a first dielectric layer on the side of the first metal layer unit;

[0111] Step S303, forming a first dielectric layer groove on a surface of the first dielectric layer facing away from the first substrate; the first dielectric layer groove is located between adjacent first metal layer units and at a pre-cutting line position of the hybrid bonding structure; the pre-cutting line position divides the hybrid bonding structure into a plurality of hybrid bonding structure units; each hybrid bonding structure unit includes at least one first metal layer unit;

[0112] Step S304, forming a first through hole at the pre-cutting line position corresponding to the groove of the first dielectric layer, such as Fig. 9 As shown; the first through hole penetrates the first substrate and the first dielectric layer, and extends into the groove of the first dielectric layer;

[0113] Step S305, providing a second substrate;

[0114] Step S306, forming a second bonding layer on a surface of one side of the second substrate, the second bonding layer comprising a plurality of second metal layer units arranged at intervals and a second dielectric layer on the side of the second metal layer unit;

[0115] Step S307, forming a second dielectric layer groove on a surface of the second dielectric layer facing away from the second substrate; the second dielectric layer groove is located between adjacent second metal layer units and at a pre-cutting position of the hybrid bonding structure;

[0116] Step S308, forming a second through hole at the pre-cutting line position corresponding to the groove of the second dielectric layer, such as Fig.10 As shown; the second through hole penetrates the second substrate and the second dielectric layer, and extends into the groove of the second dielectric layer.

[0117] Step S309, hybrid bonding the first substrate and the second substrate together to form a hybrid bonding structure, such as Fig.11 As shown; the first bonding layer and the second bonding layer are connected to form an integrated structure through hybrid bonding; wherein the first dielectric layer and the second dielectric layer are in corresponding contact and bonded together, and the first metal layer unit and the second metal layer unit are in one-to-one corresponding contact and bonded together.

[0118] In the description of this specification, the description with reference to the terms "this embodiment", "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples, unless otherwise clearly and specifically defined. In addition, the terms "first" and "second" are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" can explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0119] In the above description, the technical details of the patterning and etching of each layer are not described in detail. However, those skilled in the art should understand that various technical means can be used to form layers, regions, etc. of desired shapes. In addition, in order to form the same structure, those skilled in the art can also design methods that are not completely the same as the methods described above. In addition, although the various embodiments are described above separately, this does not mean that the measures in the various embodiments cannot be used in combination to advantage.

[0120] The above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described above, and that various obvious changes, readjustments, combinations and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention is described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may also include more other equivalent embodiments without departing from the concept of the present invention. The scope of protection of the present invention is determined by the scope of the attached claims.

Claims

1. A hybrid bonding structure, characterized in that: The hybrid bonding structure comprises: a first substrate; A first bonding layer is located on a surface of one side of the first substrate; the first bonding layer includes a plurality of first metal layer units arranged at intervals and a first dielectric layer on a side of the first metal layer unit; the first dielectric layer has a first dielectric layer groove on a surface of a side facing away from the first substrate; the first dielectric layer groove is located between adjacent first metal layer units and at a pre-cutting line position of the hybrid bonding structure; the pre-cutting line position divides the hybrid bonding structure into a plurality of hybrid bonding structure units; each of the hybrid bonding structure units includes at least one first metal layer unit; A second bonding layer is located on a surface of the first bonding layer facing away from the first substrate; the second bonding layer comprises a plurality of second metal layer units arranged at intervals and a second dielectric layer on a side of the second metal layer unit; The first bonding layer and the second bonding layer are connected to form an integrated structure through hybrid bonding; wherein the first dielectric layer and the second dielectric layer are in corresponding contact and bonded together, and the first metal layer unit and the second metal layer unit are in one-to-one corresponding contact and bonded together; A second substrate is located on a surface of the second bonding layer that is opposite to the first bonding layer.

2. The hybrid bonding structure according to claim 1, characterized in that: A second dielectric layer groove is formed on a surface of the second dielectric layer facing away from the second substrate; the second dielectric layer groove is located between adjacent second metal layer units and at a pre-cutting line position of the hybrid bonding structure.

3. The hybrid bonding structure according to claim 2, characterized in that: The positions of the first dielectric layer grooves correspond vertically to the positions of the second dielectric layer grooves, and the same group of first dielectric layer grooves and second dielectric layer grooves corresponding in position are located at the same pre-cutting line position.

4. The hybrid bonding structure according to claim 2, characterized in that: The position of the first dielectric layer groove does not correspond to the position of the second dielectric layer groove, and the first dielectric layer groove and the second dielectric layer groove are respectively located at different pre-cutting line positions.

5. The hybrid bonding structure according to claim 3 or 4, characterized in that: A first through hole is also provided at the pre-cutting line position corresponding to the groove of the first dielectric layer; the first through hole penetrates the first substrate and the first dielectric layer and extends into the groove of the first dielectric layer.

6. The hybrid bonding structure according to claim 5, characterized in that: A second through hole is also provided at the pre-cutting line position corresponding to the groove of the second dielectric layer; the second through hole penetrates the second substrate and the second dielectric layer and extends into the groove of the second dielectric layer.

7. The hybrid bonding structure according to claim 6, characterized in that: The material of the first dielectric layer is SiO2, SiCN or SiN; the material of the second dielectric layer is SiO2, SiCN or SiN; The diameter or width of the groove of the first dielectric layer is less than 50 μm to 100 μm; the depth of the groove of the first dielectric layer is 2 μm to 5 μm; The diameter or width of the groove of the second dielectric layer is less than 50 μm to 100 μm; the depth of the groove of the first dielectric layer is 2 μm to 5 μm; The diameter of the first through hole is less than 50 μm; The diameter of the second through hole is less than 50 μm.

8. A method for preparing a hybrid bonding structure, for preparing the hybrid bonding structure as claimed in claim 1, characterized in that: providing a first substrate; forming a first bonding layer on a surface of one side of the first substrate, wherein the first bonding layer comprises a plurality of first metal layer units arranged at intervals and a first dielectric layer on a side of the first metal layer unit; A first dielectric layer groove is formed on a surface of the first dielectric layer facing away from the first substrate; the first dielectric layer groove is located between adjacent first metal layer units and at a pre-cutting line position of the hybrid bonding structure; the pre-cutting line position divides the hybrid bonding structure into a plurality of hybrid bonding structure units; each of the hybrid bonding structure units includes at least one first metal layer unit; providing a second substrate; forming a second bonding layer on a surface of one side of the second substrate, wherein the second bonding layer comprises a plurality of second metal layer units arranged at intervals and a second dielectric layer on a side of the second metal layer unit; The first substrate and the second substrate are hybrid bonded together to form a hybrid bonding structure; the first bonding layer and the second bonding layer are connected into an integrated structure through hybrid bonding; wherein the first dielectric layer and the second dielectric layer are correspondingly contacted and bonded together, and the first metal layer unit and the second metal layer unit are correspondingly contacted and bonded together.

9. The method for preparing a hybrid bonding structure according to claim 8, characterized in that: Before the step of hybrid bonding the first substrate and the second substrate together, the method further includes: A second dielectric layer groove is formed on a surface of the second dielectric layer facing away from the second substrate; the second dielectric layer groove is located between adjacent second metal layer units and at a pre-cutting position of the hybrid bonding structure.

10. The method for preparing a hybrid bonding structure according to claim 9, characterized in that: After the step of forming a first dielectric layer groove on the surface of the first dielectric layer facing away from the first substrate, the method further comprises: forming a first through hole at a pre-cutting line position corresponding to the first dielectric layer groove; the first through hole penetrates the first substrate and the first dielectric layer and extends into the first dielectric layer groove; and / or: After the step of forming a second dielectric layer groove on the surface of the second dielectric layer facing away from the second substrate, the method includes: forming a second through hole at the pre-cutting line position corresponding to the second dielectric layer groove; the second through hole penetrates the second substrate and the second dielectric layer and extends into the second dielectric layer groove.

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